diff --git a/src/game/bg.c b/src/game/bg.c
index 640955cb0..be420950c 100644
--- a/src/game/bg.c
+++ b/src/game/bg.c
@@ -86,12 +86,12 @@ u32 var800a4920;
 u32 g_BgSection3;
 struct room *g_Rooms;
 u8 *g_MpRoomVisibility;
-s16 g_BgForceOnscreenRooms[350];
+RoomNum g_BgForceOnscreenRooms[350];
 s32 g_BgNumForceOnscreenRooms;
 u16 g_BgUnloadDelay240;
 u16 g_BgUnloadDelay240_2;
 u32 var800a4bf4;
-s16 g_GlareRooms[100];
+RoomNum g_GlareRooms[100];
 u32 *g_BgPrimaryData2;
 struct bgroom *g_BgRooms;
 struct bgportal *g_BgPortals;
@@ -135,7 +135,7 @@ void bgUnpausePropsInRoom(u32 roomnum, bool tintedglassonly)
 	struct prop *prop;
 	struct defaultobj *obj;
 	s16 *propnumptr;
-	s16 rooms[2];
+	RoomNum rooms[2];
 	s16 propnums[256];
 
 	rooms[0] = roomnum;
@@ -869,11 +869,11 @@ Gfx *bgRenderRoomInXray(Gfx *gdl, s32 roomnum)
 
 Gfx *bgRenderSceneInXray(Gfx *gdl)
 {
-	s16 *roomnumptr;
-	s16 *room;
+	RoomNum *roomnumptr;
+	RoomNum *room;
 	s16 i;
 	s32 j;
-	s16 roomnumsbyprop[200];
+	RoomNum roomnumsbyprop[200];
 	struct prop *prop;
 	struct prop **ptr;
 	s32 k;
@@ -969,15 +969,15 @@ Gfx *bgRenderScene(Gfx *gdl)
 	s32 firstroomnum = -1;
 	s32 i;
 	s32 roomnum;
-	s16 roomnumsbyprop[200];
+	RoomNum roomnumsbyprop[200];
 	struct prop **ptr;
 	struct drawslot *thing;
-	s16 *roomnumptr;
+	RoomNum *roomnumptr;
 	struct prop *prop;
 	s16 tmp;
-	s16 *room;
+	RoomNum *room;
 	s16 roomorder[60];
-	s16 roomnums[60];
+	RoomNum roomnums[60];
 
 	g_NumRoomsWithGlares = 0;
 
@@ -4619,7 +4619,7 @@ bool bgRoomIsLoaded(s32 room)
 	return g_Rooms[room].loaded240;
 }
 
-bool bgRoomContainsCoord(struct coord *pos, s16 roomnum)
+bool bgRoomContainsCoord(struct coord *pos, RoomNum roomnum)
 {
 	struct coord copy;
 	copy.x = pos->x;
@@ -4646,7 +4646,7 @@ bool bgRoomContainsCoord(struct coord *pos, s16 roomnum)
  * - The normal points towards the front of the portal.
  * - The room on the front side is roomnum2.
  */
-bool bgTestPosInRoomCheap(struct coord *pos, s16 roomnum)
+bool bgTestPosInRoomCheap(struct coord *pos, RoomNum roomnum)
 {
 	s32 i;
 
@@ -4672,7 +4672,7 @@ bool bgTestPosInRoomCheap(struct coord *pos, s16 roomnum)
 	return true;
 }
 
-bool bgTestPosInRoomExpensive(struct coord *pos, s16 roomnum)
+bool bgTestPosInRoomExpensive(struct coord *pos, RoomNum roomnum)
 {
 	s32 t5;
 	struct coord *next;
@@ -4780,7 +4780,7 @@ bool bgTestPosInRoomExpensive(struct coord *pos, s16 roomnum)
 	return true;
 }
 
-bool bgTestPosInRoom(struct coord *pos, s16 roomnum)
+bool bgTestPosInRoom(struct coord *pos, RoomNum roomnum)
 {
 	if (g_Rooms[roomnum].flags & ROOMFLAG_COMPLICATEDPORTALS) {
 		return bgTestPosInRoomExpensive(pos, roomnum);
@@ -4809,7 +4809,7 @@ bool bgTestPosInRoom(struct coord *pos, s16 roomnum)
  * to pos and writes the room number to the bestroom pointer. The bestroom
  * pointer is a pointer to a single s16 rather than an array.
  */
-void bgFindRoomsByPos(struct coord *posarg, s16 *inrooms, s16 *aboverooms, s32 max, s16 *bestroom)
+void bgFindRoomsByPos(struct coord *posarg, RoomNum *inrooms, RoomNum *aboverooms, s32 max, RoomNum *bestroom)
 {
 	s32 inlen = 0;
 	s32 abovelen = 0;
@@ -5332,7 +5332,7 @@ void bgTickPortalsXray(void)
 	bgChooseRoomsToLoad();
 }
 
-void bgAddToSnake(s16 fromroomnum, s16 roomnum, s16 depth, struct screenbox *box)
+void bgAddToSnake(RoomNum fromroomnum, RoomNum roomnum, s16 depth, struct screenbox *box)
 {
 	struct bgsnakeitem *item;
 	s32 i;
@@ -5419,10 +5419,10 @@ void bgConsumeSnakeItem(struct bgsnakeitem *item)
 	s32 i;
 	s16 portalnum;
 	s16 prevvalidcount;
-	s16 prevfoundroom;
-	s16 newfoundroom;
+	RoomNum prevfoundroom;
+	RoomNum newfoundroom;
 	s16 side;
-	s16 tmp;
+	RoomNum tmp;
 	bool pass;
 	struct portalmetric *metric;
 	struct screenbox prevbox;
@@ -5832,7 +5832,7 @@ Gfx *bgRenderSceneAndLoadCandidate(Gfx *gdl)
 	return gdl;
 }
 
-s32 bgGetForceOnscreenRooms(s16 *rooms, s32 len)
+s32 bgGetForceOnscreenRooms(RoomNum *rooms, s32 len)
 {
 	s32 i;
 
@@ -5845,7 +5845,7 @@ s32 bgGetForceOnscreenRooms(s16 *rooms, s32 len)
 	return i;
 }
 
-s32 bgRoomGetNeighbours(s32 roomnum, s16 *dstrooms, s32 len)
+s32 bgRoomGetNeighbours(s32 roomnum, RoomNum *dstrooms, s32 len)
 {
 	s32 count = 0;
 	s32 i;
@@ -5991,7 +5991,7 @@ bool bgPortalExists(s32 portalnum)
 
 void bgPortalSwapRooms(s32 portal)
 {
-	s16 tmp = g_BgPortals[portal].roomnum1;
+	RoomNum tmp = g_BgPortals[portal].roomnum1;
 	g_BgPortals[portal].roomnum1 = g_BgPortals[portal].roomnum2;
 	g_BgPortals[portal].roomnum2 = tmp;
 }
@@ -6210,10 +6210,10 @@ void bgCalculatePortalBbox(s32 portalnum, struct coord *bbmin, struct coord *bbm
 	}
 }
 
-void bgFindEnteredRooms(struct coord *bbmin, struct coord *bbmax, s16 *rooms, s32 maxlen, bool arg4)
+void bgFindEnteredRooms(struct coord *bbmin, struct coord *bbmax, RoomNum *rooms, s32 maxlen, bool arg4)
 {
-	s16 room;
-	s16 otherroom;
+	RoomNum room;
+	RoomNum otherroom;
 	s32 portalnum;
 	struct coord propbbmin;
 	struct coord propbbmax;
diff --git a/src/game/body.c b/src/game/body.c
index 38c313aba..5d272d3d7 100644
--- a/src/game/body.c
+++ b/src/game/body.c
@@ -346,7 +346,7 @@ s32 bodyChooseHead(s32 bodynum)
 void bodyAllocateChr(s32 stagenum, struct packedchr *packed, s32 cmdindex)
 {
 	struct pad pad;
-	s16 rooms[2];
+	RoomNum rooms[2];
 	struct chrdata *chr;
 	struct modeldef *headmodeldef;
 	struct model *model;
@@ -531,9 +531,9 @@ void bodyAllocateChr(s32 stagenum, struct packedchr *packed, s32 cmdindex)
 	}
 }
 
-struct prop *bodyAllocateEyespy(struct pad *pad, s16 room)
+struct prop *bodyAllocateEyespy(struct pad *pad, RoomNum room)
 {
-	s16 rooms[2];
+	RoomNum rooms[2];
 	struct prop *prop;
 	struct chrdata *chr;
 	struct model *model;
diff --git a/src/game/bondbike.c b/src/game/bondbike.c
index 5b33c3feb..4ef6948f2 100644
--- a/src/game/bondbike.c
+++ b/src/game/bondbike.c
@@ -107,7 +107,7 @@ void bbikeTryDismountAngle(f32 relativeangle, f32 distance)
 	struct hoverbikeobj *bike;
 	f32 angle;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	s32 result;
 	f32 ymax;
 	f32 ymin;
@@ -371,11 +371,11 @@ s32 bbikeCalculateNewPosition(struct coord *vel, f32 angledelta)
 {
 	s32 result = CDRESULT_NOCOLLISION;
 	struct coord dstpos;
-	s16 dstrooms[8];
+	RoomNum dstrooms[8];
 	struct hov hov;
 	bool hasvel = false;
 	struct hoverbikeobj *bike = (struct hoverbikeobj *) g_Vars.currentplayer->hoverbike->obj;
-	s16 spa8[20];
+	RoomNum spa8[20];
 	f32 xdiff;
 	f32 zdiff;
 	f32 ymax;
@@ -530,7 +530,7 @@ void bbikeUpdateVertical(struct coord *pos)
 {
 	struct defaultobj *bike = g_Vars.currentplayer->hoverbike->obj;
 	f32 angle;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	bool newinlift;
 	struct prop *lift = NULL;
 	f32 ground;
diff --git a/src/game/bondeyespy.c b/src/game/bondeyespy.c
index 7d4ace04e..9dd2b7f43 100644
--- a/src/game/bondeyespy.c
+++ b/src/game/bondeyespy.c
@@ -39,7 +39,7 @@ u32 g_EyespyMaxFallSpeed = 3000;
  * position 50 units above the current position, or less if the eyespy is near
  * the top of its height range.
  */
-f32 eyespyFindGround(s16 *floorroom)
+f32 eyespyFindGround(RoomNum *floorroom)
 {
 	struct prop *prop = g_Vars.currentplayer->eyespy->prop;
 	s32 inlift;
@@ -75,7 +75,7 @@ s32 eyespyTryMoveUpwards(f32 yvel)
 	struct prop *prop = g_Vars.currentplayer->eyespy->prop;
 	struct chrdata *chr = prop->chr;
 	struct coord dstpos;
-	s16 dstrooms[8];
+	RoomNum dstrooms[8];
 	s32 types;
 	u32 stack;
 	f32 f0;
@@ -118,9 +118,9 @@ s32 eyespyCalculateNewPosition(struct coord *vel)
 	struct prop *eyespyprop = g_Vars.currentplayer->eyespy->prop;
 	struct chrdata *chr = eyespyprop->chr;
 	struct coord dstpos;
-	s16 dstrooms[8];
-	s16 floorroom;
-	s16 sp74[24];
+	RoomNum dstrooms[8];
+	RoomNum floorroom;
+	RoomNum sp74[24];
 	s32 types;
 	s32 i;
 	f32 ymin;
@@ -713,7 +713,7 @@ void eyespyProcessInput(bool allowbuttons)
 	f32 angle;
 	f32 ascendspeed = 0.0f;
 	f32 prevverta = g_Vars.currentplayer->eyespy->verta;
-	s16 prevrooms[8];
+	RoomNum prevrooms[8];
 	s32 contpad2;
 	u32 stack[5];
 	f32 tmp;
diff --git a/src/game/bondgrab.c b/src/game/bondgrab.c
index 1388160ec..e44c6d170 100644
--- a/src/game/bondgrab.c
+++ b/src/game/bondgrab.c
@@ -284,7 +284,7 @@ bool bgrabTryMoveUpwards(f32 y)
 {
 	bool result;
 	struct coord newpos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	f32 ymax;
 	f32 ymin;
 	f32 radius;
@@ -320,7 +320,7 @@ s32 bgrabCalculateNewPosition(struct coord *delta, f32 angle, bool arg2)
 	s32 cdresult = CDRESULT_NOCOLLISION;
 	s32 i;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	bool ismoving = false;
 	f32 ymax;
 	f32 ymin;
diff --git a/src/game/bondgun.c b/src/game/bondgun.c
index 0aca40646..45bd3626d 100644
--- a/src/game/bondgun.c
+++ b/src/game/bondgun.c
@@ -4280,7 +4280,7 @@ struct modeldef *bgunGetCartModeldef(void)
 	return g_Vars.currentplayer->gunctrl.cartmodeldef;
 }
 
-void bgun0f09ebcc(struct defaultobj *obj, struct coord *coord, s16 *rooms, Mtxf *matrix1, struct coord *velocity, Mtxf *matrix2, struct prop *prop, struct coord *pos)
+void bgun0f09ebcc(struct defaultobj *obj, struct coord *coord, RoomNum *rooms, Mtxf *matrix1, struct coord *velocity, Mtxf *matrix2, struct prop *prop, struct coord *pos)
 {
 	struct prop *objprop = obj->prop;
 
@@ -4325,7 +4325,7 @@ void bgun0f09ed2c(struct defaultobj *obj, struct coord *newpos, Mtxf *arg2, stru
 {
 	struct prop *objprop = obj->prop;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	if (objprop) {
 		struct prop *playerprop = g_Vars.currentplayer->prop;
@@ -4348,7 +4348,7 @@ void bgun0f09ed2c(struct defaultobj *obj, struct coord *newpos, Mtxf *arg2, stru
 	}
 }
 
-struct defaultobj *bgunCreateThrownProjectile2(struct chrdata *chr, struct gset *gset, struct coord *pos, s16 *rooms, Mtxf *arg4, struct coord *velocity)
+struct defaultobj *bgunCreateThrownProjectile2(struct chrdata *chr, struct gset *gset, struct coord *pos, RoomNum *rooms, Mtxf *arg4, struct coord *velocity)
 {
 	struct defaultobj *obj = NULL;
 	struct weaponfunc *basefunc;
@@ -4457,7 +4457,7 @@ void bgunCreateThrownProjectile(s32 handnum, struct gset *gset)
 	struct weaponobj *weapon;
 	struct coord muzzlepos;
 	struct coord spawnpos;
-	s16 spawnrooms[8];
+	RoomNum spawnrooms[8];
 	bool droppinggrenade = false;
 	struct hand *hand;
 	struct coord aimpos;
@@ -6748,7 +6748,7 @@ void bgunUpdateSmoke(struct hand *hand, s32 handnum, s32 weaponnum, struct weapo
 
 	if (hand->createsmoke && (hand->state != HANDSTATE_ATTACK || hand->forcecreatesmoke)) {
 		struct coord smokepos;
-		s16 smokerooms[2];
+		RoomNum smokerooms[2];
 		s32 smoketype = SMOKETYPE_MUZZLE_AUTOMATIC;
 
 		switch (weaponnum) {
@@ -11413,7 +11413,7 @@ void bgunPlayPropHitSound(struct gset *gset, struct prop *prop, s32 texturenum)
 #endif
 }
 
-void bgunPlayGlassHitSound(struct coord *pos, s16 *rooms, s32 texturenum)
+void bgunPlayGlassHitSound(struct coord *pos, RoomNum *rooms, s32 texturenum)
 {
 	if (g_Vars.lvupdate240 > 0) {
 		struct sndstate **handle = bgunAllocateAudioHandle();
@@ -11428,7 +11428,7 @@ void bgunPlayGlassHitSound(struct coord *pos, s16 *rooms, s32 texturenum)
 	}
 }
 
-void bgunPlayBgHitSound(struct gset *gset, struct coord *hitpos, s32 texturenum, s16 *rooms)
+void bgunPlayBgHitSound(struct gset *gset, struct coord *hitpos, s32 texturenum, RoomNum *rooms)
 {
 #if VERSION >= VERSION_NTSC_1_0
 	struct sndstate **handle;
diff --git a/src/game/bondmove.c b/src/game/bondmove.c
index 8e1c2893e..2b8890203 100644
--- a/src/game/bondmove.c
+++ b/src/game/bondmove.c
@@ -394,7 +394,7 @@ f32 bmoveCalculateLookahead(void)
 	struct coord sp100;
 	u32 stack;
 	struct coord spf0;
-	s16 spe0[8];
+	RoomNum spe0[8];
 	s32 i;
 	f32 angle;
 	f32 value;
@@ -403,9 +403,9 @@ f32 bmoveCalculateLookahead(void)
 	u32 stack6;
 	struct coord spbc;
 	struct coord spb0;
-	s16 spa0[8];
-	s16 sp90[8];
-	s16 sp80[8];
+	RoomNum spa0[8];
+	RoomNum sp90[8];
+	RoomNum sp80[8];
 	s32 j;
 	f32 sp78;
 	s32 indextoremove;
@@ -1808,7 +1808,7 @@ void bmoveProcessInput(bool allowc1x, bool allowc1y, bool allowc1buttons, bool i
 	}
 }
 
-void bmoveFindEnteredRoomsByPos(struct player *player, struct coord *mid, s16 *rooms)
+void bmoveFindEnteredRoomsByPos(struct player *player, struct coord *mid, RoomNum *rooms)
 {
 	struct coord bbmin;
 	struct coord bbmax;
@@ -1826,7 +1826,7 @@ void bmoveFindEnteredRoomsByPos(struct player *player, struct coord *mid, s16 *r
 	bgFindEnteredRooms(&bbmin, &bbmax, rooms, 7, false);
 }
 
-void bmoveFindEnteredRooms(struct player *player, s16 *rooms)
+void bmoveFindEnteredRooms(struct player *player, RoomNum *rooms)
 {
 	bmoveFindEnteredRoomsByPos(player, &player->prop->pos, rooms);
 }
diff --git a/src/game/bondwalk.c b/src/game/bondwalk.c
index 545e7d779..e32d6668b 100644
--- a/src/game/bondwalk.c
+++ b/src/game/bondwalk.c
@@ -187,7 +187,7 @@ s32 bwalkTryMoveUpwards(f32 amount)
 {
 	bool result;
 	struct coord newpos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	u32 stack;
 	u32 types;
 	f32 ymax;
@@ -235,9 +235,9 @@ bool bwalkCalculateNewPosition(struct coord *vel, f32 rotateamount, bool apply,
 	s32 result = CDRESULT_NOCOLLISION;
 	f32 halfradius;
 	struct coord dstpos;
-	s16 dstrooms[8];
+	RoomNum dstrooms[8];
 	bool copyrooms = false;
-	s16 sp64[22];
+	RoomNum sp64[22];
 	s32 types;
 	f32 ymax;
 	f32 ymin;
@@ -392,7 +392,7 @@ bool bwalkCalculateNewPositionWithPush(struct coord *delta, f32 rotateamount, bo
 			} else if (obstacle->type == PROPTYPE_CHR) {
 				struct chrdata *chr = obstacle->chr;
 				struct coord newpos;
-				s16 newrooms[8];
+				RoomNum newrooms[8];
 				f32 movingdist;
 				f32 xdist;
 				f32 zdist;
@@ -713,10 +713,10 @@ void bwalkUpdateVertical(void)
 	f32 ground;
 	bool onladder;
 	bool onladder2 = false;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct coord testpos;
 	struct coord newpos;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	s32 newinlift;
 	struct prop *lift = NULL;
 	f32 sumground;
diff --git a/src/game/bot.c b/src/game/bot.c
index 9c017c7d8..017405eec 100644
--- a/src/game/bot.c
+++ b/src/game/bot.c
@@ -227,7 +227,7 @@ void botSpawn(struct chrdata *chr, u8 respawning)
 	struct defaultobj *obj;
 	struct aibot *aibot = chr->aibot;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	if (chr->prop) {
 		prop = chr->prop->child;
@@ -660,8 +660,8 @@ void botCheckPickups(struct chrdata *chr)
 	s32 i;
 	s16 *propnumptr;
 	s16 propnums[260];
-	s16 allrooms[22];
-	s16 neighbours[12];
+	RoomNum allrooms[22];
+	RoomNum neighbours[12];
 
 	roomsCopy(chr->prop->rooms, allrooms);
 
@@ -1208,7 +1208,7 @@ void botApplyProtect(struct chrdata *chr, struct prop *prop)
 	chr->aibot->forcemainloop = true;
 }
 
-void botApplyDefend(struct chrdata *chr, struct coord *pos, s16 *room, f32 angle)
+void botApplyDefend(struct chrdata *chr, struct coord *pos, RoomNum *room, f32 angle)
 {
 	chr->aibot->command = AIBOTCMD_DEFEND;
 	chr->aibot->defendholdpos.x = pos->x;
@@ -1219,7 +1219,7 @@ void botApplyDefend(struct chrdata *chr, struct coord *pos, s16 *room, f32 angle
 	chr->aibot->forcemainloop = true;
 }
 
-void botApplyHold(struct chrdata *chr, struct coord *pos, s16 *room, f32 angle)
+void botApplyHold(struct chrdata *chr, struct coord *pos, RoomNum *room, f32 angle)
 {
 	chr->aibot->command = AIBOTCMD_HOLD;
 	chr->aibot->defendholdpos.x = pos->x;
@@ -1521,7 +1521,7 @@ void botChooseGeneralTarget(struct chrdata *botchr)
 	s32 i;
 	s32 j;
 	bool distancesdone[MAX_MPCHRS];
-	s16 room = -1;
+	RoomNum room = -1;
 	struct chrdata *trychr;
 	s32 playernum;
 
diff --git a/src/game/botact.c b/src/game/botact.c
index 5d5a78fe9..f691b305e 100644
--- a/src/game/botact.c
+++ b/src/game/botact.c
@@ -440,7 +440,7 @@ s32 botactGetShootInterval60(s32 weaponnum, s32 funcnum)
  *
  * Return true if a route was found, false if not.
  */
-bool botactFindRocketRoute(struct chrdata *chr, struct coord *frompos, struct coord *topos, s16 *fromrooms, s16 *torooms, struct projectile *projectile)
+bool botactFindRocketRoute(struct chrdata *chr, struct coord *frompos, struct coord *topos, RoomNum *fromrooms, RoomNum *torooms, struct projectile *projectile)
 {
 	struct waypoint *from = waypointFindClosestToPos(frompos, fromrooms);
 	struct waypoint *to = waypointFindClosestToPos(topos, torooms);
@@ -479,7 +479,7 @@ bool botactFindRocketRoute(struct chrdata *chr, struct coord *frompos, struct co
 void botactGetRocketNextStepPos(u16 padnum, struct coord *pos)
 {
 	struct pad pad;
-	s16 rooms[2];
+	RoomNum rooms[2];
 
 	padUnpack(padnum, PADFIELD_ROOM | PADFIELD_POS, &pad);
 
diff --git a/src/game/botmgr.c b/src/game/botmgr.c
index 595c7c43c..59778fbff 100644
--- a/src/game/botmgr.c
+++ b/src/game/botmgr.c
@@ -28,7 +28,7 @@ void botmgrRemoveAll(void)
 
 void botmgrAllocateBot(s32 chrnum, s32 aibotnum)
 {
-	s16 rooms[1];
+	RoomNum rooms[1];
 	struct prop *prop;
 	struct chrdata *chr;
 	struct aibot *aibot;
diff --git a/src/game/botroom.c b/src/game/botroom.c
index e72898295..b27308f13 100644
--- a/src/game/botroom.c
+++ b/src/game/botroom.c
@@ -46,16 +46,16 @@
  * It's likely that these don't ever overflow, or they overflow minimally which
  * has no serious effect, but this should be investigated further.
  */
-bool botroomFindPos(s16 room, struct coord *pos, f32 *angleptr, s32 *padnumptr, s32 *covernumptr)
+bool botroomFindPos(RoomNum room, struct coord *pos, f32 *angleptr, s32 *padnumptr, s32 *covernumptr)
 {
 	s32 i;
 	struct waypoint *waypoint;
 	s32 waypointnum;
-	s32 covernums[40]; /// written to stack
+	s32 covernums[40];
 	s32 covercount;
-	struct cover cover; // written to stack
-	s16 rooms[2]; // written to stack
-	s32 padnums[40]; // written to stack
+	struct cover cover;
+	RoomNum rooms[2];
+	s32 padnums[40];
 	s32 padcount;
 	s32 totalcount;
 	struct pad pad;
diff --git a/src/game/camera.c b/src/game/camera.c
index 3a4b5ee14..2c1f833de 100644
--- a/src/game/camera.c
+++ b/src/game/camera.c
@@ -597,10 +597,10 @@ bool camIsPosInScreenBox(struct coord *pos, f32 arg1, struct drawslot *drawslot)
  * correct address to camIsPosInScreenBox so it can interpret the pointer as a
  * drawslot.
  */
-bool camIsPosInFovAndVisibleRoom(s16 *rooms, struct coord *pos, f32 arg2)
+bool camIsPosInFovAndVisibleRoom(RoomNum *rooms, struct coord *pos, f32 arg2)
 {
 	s32 i;
-	s16 room;
+	RoomNum room;
 	bool hasdata = false;
 	struct drawslot *thisthing;
 	struct screenbox box;
@@ -640,5 +640,5 @@ bool camIsPosInFovAndVisibleRoom(s16 *rooms, struct coord *pos, f32 arg2)
 		return false;
 	}
 
-	return camIsPosInScreenBox(pos, arg2, (struct drawslot *) (&box.array[-1][0]));
+	return camIsPosInScreenBox(pos, arg2, (struct drawslot *) &(((u8 *) &box)[-((uintptr_t) &(((struct drawslot *)0)->box))]));
 }
diff --git a/src/game/chr.c b/src/game/chr.c
index 398b5f169..667d1350a 100644
--- a/src/game/chr.c
+++ b/src/game/chr.c
@@ -197,7 +197,7 @@ void chrSetPerimEnabled(struct chrdata *chr, bool enable)
  * pos and rooms for the chr. It does collision checks and updates dstpos and
  * dstrooms to valid ones if needed.
  */
-void chrCalculatePushPos(struct chrdata *chr, struct coord *dstpos, s16 *dstrooms, bool arg3)
+void chrCalculatePushPos(struct chrdata *chr, struct coord *dstpos, RoomNum *dstrooms, bool arg3)
 {
 	f32 ymax;
 	f32 ymin;
@@ -210,7 +210,7 @@ void chrCalculatePushPos(struct chrdata *chr, struct coord *dstpos, s16 *dstroom
 	f32 halfradius;
 	struct defaultobj *chair = NULL;
 	s32 cdresult;
-	s16 sp84[20];
+	RoomNum sp84[20];
 #if VERSION < VERSION_NTSC_1_0
 	s32 i;
 #endif
@@ -478,14 +478,14 @@ void chrCalculatePushPos(struct chrdata *chr, struct coord *dstpos, s16 *dstroom
 }
 
 #if VERSION >= VERSION_NTSC_1_0
-bool chr0f01f264(struct chrdata *chr, struct coord *pos, s16 *rooms, f32 arg3, bool arg4)
+bool chr0f01f264(struct chrdata *chr, struct coord *pos, RoomNum *rooms, f32 arg3, bool arg4)
 #else
-bool chr0f01f264(struct chrdata *chr, struct coord *pos, s16 *rooms, f32 arg3)
+bool chr0f01f264(struct chrdata *chr, struct coord *pos, RoomNum *rooms, f32 arg3)
 #endif
 {
 	bool result;
 	struct coord newpos;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	f32 ymax;
 	f32 ymin;
 	f32 radius;
@@ -520,7 +520,7 @@ bool chr0f01f378(struct model *model, struct coord *arg1, struct coord *arg2, f3
 	struct prop *lift;
 	s32 i;
 	f32 ground;
-	s16 spfc[8];
+	RoomNum spfc[8];
 	f32 manground = chr->manground;
 	s32 race = CHRRACE(chr);
 	f32 yincrement = 0.0f;
@@ -531,7 +531,7 @@ bool chr0f01f378(struct model *model, struct coord *arg1, struct coord *arg2, f3
 	f32 lvupdate60f;
 	f32 lvupdate60freal;
 	struct coord spd0;
-	s16 spc0[8];
+	RoomNum spc0[8];
 #endif
 
 	// NTSC beta reads g_Vars lvupdate properties throughout this function,
@@ -775,9 +775,9 @@ bool chr0f01f378(struct model *model, struct coord *arg1, struct coord *arg2, f3
 			arg2->y -= chr->manground;
 		} else {
 			struct coord *sp98;
-			s16 *sp94;
+			RoomNum *sp94;
 			struct coord sp88;
-			s16 sp78[8];
+			RoomNum sp78[8];
 			f32 ground;
 			struct modelnode *node;
 			u16 nodetype;
@@ -1290,7 +1290,7 @@ void chrInit(struct prop *prop, u8 *ailist)
 }
 
 struct prop *chr0f020b14(struct prop *prop, struct model *model,
-		struct coord *pos, s16 *rooms, f32 faceangle, u8 *ailist)
+		struct coord *pos, RoomNum *rooms, f32 faceangle, u8 *ailist)
 {
 	struct chrdata *chr;
 	struct coord testpos;
@@ -1345,7 +1345,7 @@ struct prop *chr0f020b14(struct prop *prop, struct model *model,
 	return prop;
 }
 
-struct prop *chrAllocate(struct model *model, struct coord *pos, s16 *rooms, f32 faceangle, u8 *ailist)
+struct prop *chrAllocate(struct model *model, struct coord *pos, RoomNum *rooms, f32 faceangle, u8 *ailist)
 {
 	struct prop *prop = propAllocate();
 
@@ -1871,7 +1871,7 @@ void chrHandleJointPositioned(s32 joint, Mtxf *mtx)
 	}
 }
 
-void chr0f021fa8(struct chrdata *chr, struct coord *pos, s16 *rooms)
+void chr0f021fa8(struct chrdata *chr, struct coord *pos, RoomNum *rooms)
 {
 	struct coord lower;
 	struct coord upper;
@@ -1904,7 +1904,7 @@ void chr0f021fa8(struct chrdata *chr, struct coord *pos, s16 *rooms)
 	bgFindEnteredRooms(&lower, &upper, rooms, 7, true);
 }
 
-void chr0f022084(struct chrdata *chr, s16 *room)
+void chr0f022084(struct chrdata *chr, RoomNum *room)
 {
 	chr0f021fa8(chr, &chr->prop->pos, room);
 }
diff --git a/src/game/chraction.c b/src/game/chraction.c
index 65b834e5a..4ca511b18 100644
--- a/src/game/chraction.c
+++ b/src/game/chraction.c
@@ -1520,7 +1520,7 @@ f32 chrGetAttackEntityRelativeAngle(struct chrdata *chr, s32 attackflags, s32 en
 {
 	f32 angle;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	if (attackflags & ATTACKFLAG_AIMFORWARD) {
 		return 0;
@@ -5109,13 +5109,13 @@ void chrDie(struct chrdata *chr, s32 aplayernum)
 	}
 }
 
-bool func0f03645c(struct chrdata *chr, struct coord *arg1, s16 *arg2, struct coord *arg3, struct coord *arg4, s32 arg5)
+bool func0f03645c(struct chrdata *chr, struct coord *arg1, RoomNum *arg2, struct coord *arg3, struct coord *arg4, s32 arg5)
 {
 	bool result = false;
 	f32 ymax;
 	f32 ymin;
 	f32 radius;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct prop *prop = chr->prop;
 
 	chrGetBbox(prop, &radius, &ymax, &ymin);
@@ -5132,7 +5132,7 @@ bool func0f03645c(struct chrdata *chr, struct coord *arg1, s16 *arg2, struct coo
 	return result;
 }
 
-bool func0f03654c(struct chrdata *chr, struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2, struct coord *vector, f32 arg6, u32 types)
+bool func0f03654c(struct chrdata *chr, struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2, struct coord *vector, f32 arg6, u32 types)
 {
 	struct coord tmp;
 	f32 a;
@@ -5144,7 +5144,7 @@ bool func0f03654c(struct chrdata *chr, struct coord *pos, s16 *rooms, struct coo
 	f32 radius;
 	struct coord sp5c;
 	struct coord sp50;
-	s16 sp40[8];
+	RoomNum sp40[8];
 	f32 mult;
 
 	prop = chr->prop;
@@ -5302,15 +5302,15 @@ bool chrCanJumpInDirection(struct chrdata *chr, bool side, f32 distance)
 	return propchrHasClearLineToPos(prop, &dstpos, &vector);
 }
 
-bool chrIsRoomOffScreen(struct chrdata *chr, struct coord *waypos, s16 *wayrooms)
+bool chrIsRoomOffScreen(struct chrdata *chr, struct coord *waypos, RoomNum *wayrooms)
 {
 	struct prop *prop = chr->prop;
-	s16 sp7c[20];
+	RoomNum sp7c[20];
 	u32 stack;
 	s32 i;
-	s16 sp64[8];
+	RoomNum sp64[8];
 	bool offscreen = true;
-	s16 sp50[8];
+	RoomNum sp50[8];
 
 	if ((chr->hidden & CHRHFLAG_CLOAKED) == 0 || USINGDEVICE(DEVICE_IRSCANNER)) {
 		func0f065dfc(&prop->pos, prop->rooms, waypos, sp64, sp7c, 20);
@@ -5364,7 +5364,7 @@ void chrGoPosInitMagic(struct chrdata *chr, struct waydata *waydata, struct coor
 	chrSetLookAngle(chr, angle);
 }
 
-void chrGoPosGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, s16 *rooms, u32 *flags)
+void chrGoPosGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, RoomNum *rooms, u32 *flags)
 {
 	struct waypoint *waypoint = chr->act_gopos.waypoints[chr->act_gopos.curindex];
 	struct pad pad;
@@ -5396,7 +5396,7 @@ void chrGoPosGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos,
 	}
 }
 
-void chrGoPosGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, s16 *rooms)
+void chrGoPosGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, RoomNum *rooms)
 {
 	chrGoPosGetCurWaypointInfoWithFlags(chr, pos, rooms, NULL);
 }
@@ -5421,7 +5421,7 @@ s32 chrGoPosCalculateBaseTtl(struct chrdata *chr)
 	f32 zdiff;
 	u32 stack;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	f32 speed;
 
 	chrGoPosGetCurWaypointInfo(chr, &pos, rooms);
@@ -5487,7 +5487,7 @@ void chrGoPosConsiderRestart(struct chrdata *chr)
 void chrGoPosInitExpensive(struct chrdata *chr)
 {
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	chrGoPosGetCurWaypointInfo(chr, &pos, rooms);
 
@@ -5600,7 +5600,7 @@ s16 chrPatrolCalculatePadNum(struct chrdata *chr, s32 numsteps)
 	return *padnumptr;
 }
 
-void chrPatrolGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, s16 *rooms, u32 *flags)
+void chrPatrolGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, RoomNum *rooms, u32 *flags)
 {
 	s32 padnum = chrPatrolCalculatePadNum(chr, 0);
 	struct pad pad;
@@ -5619,14 +5619,14 @@ void chrPatrolGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos
 	}
 }
 
-void chrPatrolGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, s16 *rooms)
+void chrPatrolGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, RoomNum *rooms)
 {
 	chrPatrolGetCurWaypointInfoWithFlags(chr, pos, rooms, NULL);
 }
 
 void func0f037580(struct chrdata *chr)
 {
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	chr->act_patrol.waydata.mode = WAYMODE_INIT;
 	chr->act_patrol.waydata.iter = 0;
@@ -5645,26 +5645,26 @@ void func0f0375b0(struct chrdata *chr)
 	func0f037580(chr);
 }
 
-void chrNavTickMagic(struct chrdata *chr, struct waydata *waydata, f32 speed, struct coord *arg3, s16 *rooms)
+void chrNavTickMagic(struct chrdata *chr, struct waydata *waydata, f32 speed, struct coord *arg3, RoomNum *rooms)
 {
-	s16 sp118[8];
+	RoomNum sp118[8];
 	f32 ymax;
 	f32 ymin;
 	f32 radius;
 	f32 ground;
 	u16 floorcol;
 	u8 floortype;
-	s16 floorroom;
+	RoomNum floorroom;
 	struct coord spf4;
 	struct prop *prop = chr->prop;
 	union modelrwdata *rwdata;
 	struct waypoint *waypoint;
 	struct coord spdc;
-	s16 spcc[8];
+	RoomNum spcc[8];
 	u32 stack[4];
 	struct pad pad;
 	struct coord sp5c;
-	s16 sp4c[8];
+	RoomNum sp4c[8];
 
 	chr->invalidmove = 0;
 	chr->lastmoveok60 = g_Vars.lvframe60;
@@ -5773,7 +5773,7 @@ void chrNavTickMagic(struct chrdata *chr, struct waydata *waydata, f32 speed, st
  */
 void chrCalculatePosition(struct chrdata *chr, struct coord *pos)
 {
-	s16 rooms[8];
+	RoomNum rooms[8];
 	f32 frac;
 
 	if (chr->actiontype == ACT_PATROL && chr->act_patrol.waydata.mode == WAYMODE_MAGIC) {
@@ -6075,7 +6075,7 @@ void chrGoPosChooseAnimation(struct chrdata *chr)
 	}
 }
 
-bool chrGoToRoomPos(struct chrdata *chr, struct coord *pos, s16 *room, u32 goposflags)
+bool chrGoToRoomPos(struct chrdata *chr, struct coord *pos, RoomNum *room, u32 goposflags)
 {
 	struct prop *prop = chr->prop;
 	struct waypoint *nextwaypoint;
@@ -6083,7 +6083,7 @@ bool chrGoToRoomPos(struct chrdata *chr, struct coord *pos, s16 *room, u32 gopos
 	struct waypoint *waypoints[MAX_CHRWAYPOINTS];
 	s32 i;
 	struct coord curwppos;
-	s16 curwprooms[8];
+	RoomNum curwprooms[8];
 	s32 isgopos = chr->actiontype == ACT_GOPOS
 		&& (chr->act_gopos.flags & GOPOSMASK_SPEED) == (goposflags & 0xff & GOPOSMASK_SPEED)
 		&& !chrGoPosIsWaiting(chr);
@@ -6249,15 +6249,15 @@ void chrStartPatrol(struct chrdata *chr, struct path *path)
 	s32 *padnumptr;
 	struct pad pad;
 	struct coord nextpos;
-	s16 nextrooms[8];
-	s16 rooms[8];
+	RoomNum nextrooms[8];
+	RoomNum rooms[8];
 	f32 ymax;
 	f32 ymin;
 	f32 radius;
 	f32 bestdistance = 0;
 	s32 nextstep = -1;
 	struct prop *prop = chr->prop;
-	s16 sp60[2];
+	RoomNum sp60[2];
 
 	if (CHRRACE(chr) != RACE_EYESPY) {
 		// Do some kind of collision test with the pad to resume from...
@@ -6361,11 +6361,11 @@ void chrRecordLastVisibleTargetTime(struct chrdata *chr)
 	chr->lastvisibletarget60 = g_Vars.lvframe60;
 }
 
-bool chrHasLosToEntity(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms, bool allowextraheight, u32 attackflags, u32 entityid)
+bool chrHasLosToEntity(struct chrdata *chr, struct coord *chrpos, RoomNum *chrrooms, bool allowextraheight, u32 attackflags, u32 entityid)
 {
 	bool result = false;
 	struct coord targetpos;
-	s16 targetrooms[8];
+	RoomNum targetrooms[8];
 	struct prop *targetprop;
 	struct chrdata *targetchr;
 	u32 types;
@@ -6404,7 +6404,7 @@ bool chrHasLosToEntity(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms,
 
 				if (allowextraheight && (chr->chrflags & CHRCFLAG_LOSEXTRAHEIGHT)) {
 					struct coord frompos;
-					s16 fromrooms[8];
+					RoomNum fromrooms[8];
 
 					frompos.x = chrpos->x;
 					frompos.y = chrpos->y + 70;
@@ -6451,7 +6451,7 @@ bool chrHasLosToEntity(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms,
 	return result;
 }
 
-bool chrHasLosToAttackTarget(struct chrdata *chr, struct coord *pos, s16 *rooms, bool allowextraheight)
+bool chrHasLosToAttackTarget(struct chrdata *chr, struct coord *pos, RoomNum *rooms, bool allowextraheight)
 {
 	u32 attackflags = ATTACKFLAG_AIMATTARGET;
 	u32 entityid = 0;
@@ -6464,16 +6464,16 @@ bool chrHasLosToAttackTarget(struct chrdata *chr, struct coord *pos, s16 *rooms,
 	return chrHasLosToEntity(chr, pos, rooms, allowextraheight, attackflags, entityid);
 }
 
-bool chrHasLosToChr(struct chrdata *chr, struct chrdata *target, s16 *room)
+bool chrHasLosToChr(struct chrdata *chr, struct chrdata *target, RoomNum *room)
 {
 	bool cansee = false;
 	u32 stack;
-	s16 sp88[] = {-1, 0, 0, 0, 0, 0, 0, 0};
+	RoomNum sp88[] = {-1, 0, 0, 0, 0, 0, 0, 0};
 
 	if (!botIsTargetInvisible(chr, target)) {
 		struct prop *prop = chr->prop;
 		struct coord pos;
-		s16 rooms[8];
+		RoomNum rooms[8];
 
 		pos.x = prop->pos.x;
 		pos.y = chr->ground + chr->height - 20;
@@ -6529,12 +6529,12 @@ bool chrHasLosToTarget(struct chrdata *chr)
 	return cansee;
 }
 
-bool chrHasLosToPos(struct chrdata *chr, struct coord *pos, s16 *rooms)
+bool chrHasLosToPos(struct chrdata *chr, struct coord *pos, RoomNum *rooms)
 {
 	struct prop *prop = chr->prop;
 	bool result = false;
 	struct coord eyepos;
-	s16 chrrooms[8];
+	RoomNum chrrooms[8];
 
 	eyepos.x = prop->pos.x;
 	eyepos.y = chr->ground + chr->height - 20;
@@ -6558,7 +6558,7 @@ bool chrHasLosToPos(struct chrdata *chr, struct coord *pos, s16 *rooms)
  * Wasteful because this function calculates angles then does nothing with them.
  * chrHasLosToPos is called with the same arguments regardless.
  */
-bool chrHasLosToPosWasteful(struct chrdata *chr, struct coord *pos, s16 *rooms)
+bool chrHasLosToPosWasteful(struct chrdata *chr, struct coord *pos, RoomNum *rooms)
 {
 	f32 facingangle = chrGetInverseTheta(chr);
 	f32 posangle = atan2f(pos->x - chr->prop->pos.x, pos->z - chr->prop->pos.z);
@@ -7122,7 +7122,7 @@ bool chrGoToPad(struct chrdata *chr, s32 padnum, u32 goposflags)
 		if (padnum >= 0)
 #endif
 		{
-			s16 rooms[2];
+			RoomNum rooms[2];
 			struct pad pad;
 
 			padUnpack(padnum, PADFIELD_ROOM | PADFIELD_POS, &pad);
@@ -7234,8 +7234,8 @@ bool chrGoToProp(struct chrdata *chr, struct prop *prop, u32 goposflags)
 
 bool chrGoToPos(struct chrdata *chr, struct coord *pos, u32 goposflags)
 {
-	s16 inrooms[21];
-	s16 aboverooms[21];
+	RoomNum inrooms[21];
+	RoomNum aboverooms[21];
 
 	if (chrIsReadyForOrders(chr)) {
 #if VERSION >= VERSION_NTSC_1_0
@@ -7246,7 +7246,7 @@ bool chrGoToPos(struct chrdata *chr, struct coord *pos, u32 goposflags)
 		if (g_NumChrsSeenPlayerRecently2 < 10)
 #endif
 		{
-			s16 *rooms = NULL;
+			RoomNum *rooms = NULL;
 
 			bgFindRoomsByPos(pos, inrooms, aboverooms, 20, NULL);
 
@@ -7372,7 +7372,7 @@ bool chrTryRunFromTarget(struct chrdata *chr)
 	f32 ymin;
 	f32 radius;
 	struct coord dst;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct coord diff;
 	f32 distance;
 
@@ -7492,7 +7492,7 @@ bool chrGoToCoverProp(struct chrdata *chr)
 					f32 propheight;
 					f32 chrheight;
 					struct coord dstpos;
-					s16 dstrooms[8];
+					RoomNum dstrooms[8];
 
 					propGetBbox(prop, &propradius, &propymax, &propymin);
 					propGetBbox(chrprop, &chrradius, &chrymax, &chrymin);
@@ -9032,7 +9032,7 @@ bool func0f03e9f4(struct chrdata *chr, struct attackanimconfig *animcfg, bool fi
 		f32 sqdist;
 		bool holdturn;
 		struct coord targetpos;
-		s16 targetrooms[8];
+		RoomNum targetrooms[8];
 
 		sp178 = targetprop->pos.x - chrprop->pos.x;
 		sp174 = targetprop->pos.y - chrprop->pos.y;
@@ -9867,10 +9867,10 @@ void chrTickShoot(struct chrdata *chr, s32 handnum)
 		bool shotdue;
 		bool makebeam;
 		struct coord gunpos;
-		s16 gunrooms[8];
+		RoomNum gunrooms[8];
 		struct coord hitpos;
 		bool hitsomething;
-		s16 hitrooms[8];
+		RoomNum hitrooms[8];
 		bool queriedhitrooms;
 		s32 tickspershot;
 
@@ -11771,7 +11771,7 @@ void func0f044b68(struct coord *arg0, struct coord *arg1, struct coord *arg2)
  * This is similar to chrNavCheckForObstacle. The difference between the two are
  * not yet understood.
  */
-bool chrNavCanSeeNextPos(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms, struct coord *aimpos, struct coord *leftpos, struct coord *rightpos, f32 negchrradius, f32 chrradius, s32 cdtypes, s32 arg9)
+bool chrNavCanSeeNextPos(struct chrdata *chr, struct coord *chrpos, RoomNum *chrrooms, struct coord *aimpos, struct coord *leftpos, struct coord *rightpos, f32 negchrradius, f32 chrradius, s32 cdtypes, s32 arg9)
 {
 	struct coord spd4;
 	f32 spd0;
@@ -11791,8 +11791,8 @@ bool chrNavCanSeeNextPos(struct chrdata *chr, struct coord *chrpos, s16 *chrroom
 	f32 radius2;
 	struct coord sp6c;
 	struct coord sp60;
-	s16 sp50[8];
-	s16 sp40[8];
+	RoomNum sp50[8];
+	RoomNum sp40[8];
 	struct prop *prop = chr->prop;
 
 	chrGetBbox(prop, &radius2, &ymax, &ymin);
@@ -11928,7 +11928,7 @@ bool chrNavCanSeeNextPos(struct chrdata *chr, struct coord *chrpos, s16 *chrroom
  * This is similar to chrNavCanSeeNextPos. The only difference is this one uses
  * the value1 and value2 variables.
  */
-bool chrNavCheckForObstacle(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms, struct coord *aimpos, struct coord *leftpos, struct coord *rightpos, f32 negchrradius, f32 chrradius, s32 cdtypes, bool hasobstacle)
+bool chrNavCheckForObstacle(struct chrdata *chr, struct coord *chrpos, RoomNum *chrrooms, struct coord *aimpos, struct coord *leftpos, struct coord *rightpos, f32 negchrradius, f32 chrradius, s32 cdtypes, bool hasobstacle)
 {
 	struct coord spd4;
 	f32 spd0;
@@ -11950,8 +11950,8 @@ bool chrNavCheckForObstacle(struct chrdata *chr, struct coord *chrpos, s16 *chrr
 	f32 radius2;
 	struct coord sp6c;
 	struct coord sp60;
-	s16 sp50[8];
-	s16 sp40[8];
+	RoomNum sp50[8];
+	RoomNum sp40[8];
 	struct prop *prop = chr->prop;
 
 	chrGetBbox(prop, &radius2, &ymax, &ymin);
@@ -12656,7 +12656,7 @@ bool chrGoPosUpdateLiftAction(struct chrdata *chr, u32 curpadflags, bool arg2, b
 			// Waiting for door to close or lift to arrive at destination
 			if (arg2 || chr->liftaction == LIFTACTION_WAITINGONLIFT) {
 				// Continue waiting
-				s16 rooms[] = {0, -1};
+				RoomNum rooms[] = {0, -1};
 				u32 stack2;
 
 				rooms[0] = nextpad.room;
@@ -12727,13 +12727,13 @@ void chrTickGoPos(struct chrdata *chr)
 {
 	struct waypoint *waypoint;
 	struct coord nextpos;
-	s16 nextrooms[8];
+	RoomNum nextrooms[8];
 	struct prop *prop = chr->prop;
 	bool enteringmagic = false;
 	struct pad pad;
 	bool sp240 = true;
 	struct coord curwppos;
-	s16 curwprooms[8];
+	RoomNum curwprooms[8];
 	u32 curwpflags;
 
 	chr->act_gopos.flags &= ~(GOPOSFLAG_CROUCH | GOPOSFLAG_DUCK);
@@ -13025,7 +13025,7 @@ void chrTickPatrol(struct chrdata *chr)
 	bool enteringmagic;
 	u32 flags = 0;
 	struct coord sp58;
-	s16 sp48[8];
+	RoomNum sp48[8];
 	s32 arrivinglaterally;
 	s32 arriving;
 	bool advance;
@@ -13742,7 +13742,7 @@ f32 chrGetAngleToTarget(struct chrdata *chr)
 	return chrGetAngleToPos(chr, &prop->pos);
 }
 
-void chrGetAttackEntityPos(struct chrdata *chr, u32 attackflags, s32 entityid, struct coord *pos, s16 *rooms)
+void chrGetAttackEntityPos(struct chrdata *chr, u32 attackflags, s32 entityid, struct coord *pos, RoomNum *rooms)
 {
 	struct prop *targetprop;
 	struct chrdata *targetchr;
@@ -14585,7 +14585,7 @@ bool waypointIsWithin90DegreesOfPosAngle(struct waypoint *waypoint, struct coord
  * those are in the quadrant then no further checks are made and the function
  * returns -1.
  */
-s32 chrFindWaypointWithinPosQuadrant(struct coord *pos, s16 *rooms, f32 angle, u8 quadrant)
+s32 chrFindWaypointWithinPosQuadrant(struct coord *pos, RoomNum *rooms, f32 angle, u8 quadrant)
 {
 	struct waypoint *waypoint = waypointFindClosestToPos(pos, rooms);
 	s32 neighbournum;
@@ -14716,7 +14716,7 @@ bool chrSetChrPresetToChrNearSelf(u8 checktype, struct chrdata *chr, f32 distanc
 bool chrSetChrPresetToChrNearPad(u32 checktype, struct chrdata *chr, f32 distance, s32 padnum)
 {
 	struct pad pad;
-	s16 rooms[2];
+	RoomNum rooms[2];
 
 	padnum = chrResolvePadId(chr, padnum);
 	padUnpack(padnum, PADFIELD_POS | PADFIELD_ROOM, &pad);
@@ -14727,19 +14727,19 @@ bool chrSetChrPresetToChrNearPad(u32 checktype, struct chrdata *chr, f32 distanc
 	return chrSetChrPresetToChrNearPos(checktype, chr, distance, &pad.pos, rooms);
 }
 
-bool chrSetChrPresetToChrNearPos(u8 checktype, struct chrdata *chr, f32 distance, struct coord *pos, s16 *rooms)
+bool chrSetChrPresetToChrNearPos(u8 checktype, struct chrdata *chr, f32 distance, struct coord *pos, RoomNum *rooms)
 {
 	s32 i;
 	s16 *propnumptr;
 	s16 propnums[256];
-	s16 allrooms[21];
+	RoomNum allrooms[21];
 	f32 xmin = pos->x - distance;
 	f32 xmax = pos->x + distance;
 	f32 ymin = pos->y - distance;
 	f32 ymax = pos->y + distance;
 	f32 zmin = pos->z - distance;
 	f32 zmax = pos->z + distance;
-	s16 neighbours[11];
+	RoomNum neighbours[11];
 
 	roomsCopy(rooms, allrooms);
 
@@ -14912,7 +14912,7 @@ bool chrSetPadPresetToPadOnRouteToTarget(struct chrdata *chr)
 	return false;
 }
 
-bool chrIsPosOffScreen(struct coord *pos, s16 *rooms)
+bool chrIsPosOffScreen(struct coord *pos, RoomNum *rooms)
 {
 	bool offscreen = true;
 	s32 i;
@@ -14943,12 +14943,12 @@ bool chrIsPosOffScreen(struct coord *pos, s16 *rooms)
  * If the spawn cannot happen, the function return false.
  */
 #if VERSION >= VERSION_NTSC_1_0
-bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, s16 *rooms, f32 angle, bool allowonscreen, bool force, bool onlysurrounding)
+bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, RoomNum *rooms, f32 angle, bool allowonscreen, bool force, bool onlysurrounding)
 {
 	struct coord testpos;
 	s32 i;
 	u32 types;
-	s16 testrooms[8];
+	RoomNum testrooms[8];
 	f32 ymin;
 	f32 ymax = 200;
 	f32 curangle = angle;
@@ -15030,12 +15030,12 @@ bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, s16 *rooms, f32 angl
  * ntsc-beta's version of this function doesn't have the onlysurrounding argument
  * nor out of bounds checking, and lacks the reduction for the volume test.
  */
-bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, s16 *rooms, f32 angle, bool allowonscreen, bool force)
+bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, RoomNum *rooms, f32 angle, bool allowonscreen, bool force)
 {
 	struct coord testpos;
 	s32 i;
 	u32 types;
-	s16 testrooms[8];
+	RoomNum testrooms[8];
 	f32 curangle = angle;
 
 	if (force) {
@@ -15084,11 +15084,11 @@ bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, s16 *rooms, f32 angl
  * triggered, but the function will not attempt to spawn the chr until the next
  * time it's called.
  */
-struct prop *chrSpawnAtCoord(s32 bodynum, s32 headnum, struct coord *pos, s16 *rooms, f32 angle, u8 *ailist, u32 spawnflags)
+struct prop *chrSpawnAtCoord(s32 bodynum, s32 headnum, struct coord *pos, RoomNum *rooms, f32 angle, u8 *ailist, u32 spawnflags)
 {
 	struct prop *prop;
 	struct coord pos2;
-	s16 rooms2[8];
+	RoomNum rooms2[8];
 	s32 stack;
 
 	if (chrsGetNumFree() > 1) {
@@ -15199,7 +15199,7 @@ struct prop *chrSpawnAtPad(struct chrdata *basechr, s32 body, s32 head, s32 pad_
 {
 	s32 resolved_pad_id = chrResolvePadId(basechr, pad_id);
 	struct pad pad;
-	s16 room[2];
+	RoomNum room[2];
 	f32 fvalue;
 	padUnpack(resolved_pad_id, PADFIELD_POS | PADFIELD_LOOK | PADFIELD_ROOM, &pad);
 	fvalue = atan2f(pad.look.x, pad.look.z);
@@ -15253,10 +15253,10 @@ void func0f04b740(void)
 	// empty
 }
 
-bool chrMoveToPos(struct chrdata *chr, struct coord *pos, s16 *rooms, f32 angle, bool force)
+bool chrMoveToPos(struct chrdata *chr, struct coord *pos, RoomNum *rooms, f32 angle, bool force)
 {
 	struct coord pos2;
-	s16 rooms2[8];
+	RoomNum rooms2[8];
 	bool result = false;
 	u32 nodetype;
 	union modelrwdata *rwdata;
@@ -15356,7 +15356,7 @@ bool chrCheckCoverOutOfSight(struct chrdata *chr, s32 covernum, bool soft)
 
 s32 chrAssignCoverByCriteria(struct chrdata *chr, u16 criteria, s32 refdist)
 {
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct cover cover;
 	struct covercandidate tmp;
 	s32 oldcover;
@@ -15619,7 +15619,7 @@ bool chrRunFromPos(struct chrdata *chr, u32 goposflags, f32 rundist, struct coor
 {
 	f32 curdistfrompos;
 	struct coord delta;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	if (chrIsReadyForOrders(chr)) {
 		delta.x = chr->prop->pos.x - frompos->x;
@@ -16010,12 +16010,12 @@ bool audioWasNotPlayedRecently(s16 audioid)
 }
 
 #if VERSION >= VERSION_NTSC_1_0
-Gfx *chrsRenderChrStats(Gfx *gdl, s16 *rooms)
+Gfx *chrsRenderChrStats(Gfx *gdl, RoomNum *rooms)
 {
 	return gdl;
 }
 #else
-Gfx *chrsRenderChrStats(Gfx *gdl, s16 *rooms)
+Gfx *chrsRenderChrStats(Gfx *gdl, RoomNum *rooms)
 {
 	s32 x;
 	s32 y;
@@ -16127,7 +16127,7 @@ void chrAvoid(struct chrdata *chr)
 	f32 zdiff;
 	f32 halfchrradius;
 	f32 chrangle = modelGetChrRotY(chr->model);
-	s16 dstrooms[8];
+	RoomNum dstrooms[8];
 	struct coord dstpos;
 
 	// @bug: This shouldn't be here, and the perim is not enabled again
diff --git a/src/game/chraicommands.c b/src/game/chraicommands.c
index f7aba6865..49e55c0e6 100644
--- a/src/game/chraicommands.c
+++ b/src/game/chraicommands.c
@@ -2361,7 +2361,7 @@ bool aiObjectMoveToPad(void)
 	u16 padnum = cmd[4] | (cmd[3] << 8);
 	Mtxf matrix;
 	struct pad pad;
-	s16 rooms[2];
+	RoomNum rooms[2];
 
 	if (obj && obj->prop) {
 		padUnpack(padnum, PADFIELD_POS | PADFIELD_LOOK | PADFIELD_UP | PADFIELD_ROOM, &pad);
@@ -5184,7 +5184,7 @@ bool aiChrMoveToPad(void)
 	bool pass = false;
 	f32 theta;
 	struct pad pad;
-	s16 rooms[2];
+	RoomNum rooms[2];
 	struct chrdata *chr2;
 
 	if (chr && chr->prop) {
@@ -9611,7 +9611,7 @@ bool aiSetDrCarollImages(void)
 bool aiSetRoomFlag(void)
 {
 	u8 *cmd = g_Vars.ailist + g_Vars.aioffset;
-	s16 roomnum = cmd[3] | cmd[2] << 8;
+	RoomNum roomnum = cmd[3] | cmd[2] << 8;
 	s16 flag = cmd[5] | cmd[4] << 8;
 
 	g_Rooms[roomnum].flags |= flag;
@@ -9658,7 +9658,7 @@ bool aiShowCutsceneChrs(void)
 bool aiConfigureEnvironment(void)
 {
 	u8 *cmd = g_Vars.ailist + g_Vars.aioffset;
-	s16 room_id = (cmd[3] | (cmd[2] << 8));
+	RoomNum room_id = (cmd[3] | (cmd[2] << 8));
 	s32 value = cmd[5];
 	s32 i;
 
diff --git a/src/game/dlights.c b/src/game/dlights.c
index 3def7eaf0..c00836a0a 100644
--- a/src/game/dlights.c
+++ b/src/game/dlights.c
@@ -311,7 +311,7 @@ void roomSetDefaults(struct room *room)
 	room->lightop_duration240 = 0;
 }
 
-Gfx *lightsSetForRoom(Gfx *gdl, s16 roomnum)
+Gfx *lightsSetForRoom(Gfx *gdl, RoomNum roomnum)
 {
 	Lights1 *lights = gfxAllocate(sizeof(Lights1));
 
@@ -989,7 +989,7 @@ bool lightTickBroken(s32 roomnum, s32 lightnum)
 			f32 rand1 = 2.0f * RANDOMFRAC() - 1.0f; // range -1 to 1
 			f32 rand2 = 2.0f * RANDOMFRAC() - 1.0f; // range -1 to 1
 			s32 sparktype = -1;
-			s16 smokerooms[2];
+			RoomNum smokerooms[2];
 			struct bgroom *room;
 
 			spc8.x = light->bbox[1].x - light->bbox[0].x;
diff --git a/src/game/dyntex.c b/src/game/dyntex.c
index 33600ae35..97ebf827c 100644
--- a/src/game/dyntex.c
+++ b/src/game/dyntex.c
@@ -354,7 +354,7 @@ void dyntexSetCurrentType(s16 type)
 	g_DyntexCurType = type;
 }
 
-void dyntexSetCurrentRoom(s16 roomnum)
+void dyntexSetCurrentRoom(RoomNum roomnum)
 {
 	s32 i;
 
diff --git a/src/game/explosions.c b/src/game/explosions.c
index 43a8a8e62..18ce20f59 100644
--- a/src/game/explosions.c
+++ b/src/game/explosions.c
@@ -81,18 +81,18 @@ struct explosiontype g_ExplosionTypes[] = {
 	/*25*/ { 640, 480, 32,  11.2, 1600, 1000, 1000, 180, 2, 5, SMOKETYPE_NONE,         0x80a4, 4     },
 };
 
-bool explosionCreateSimple(struct prop *prop, struct coord *pos, s16 *rooms, s16 type, s32 playernum)
+bool explosionCreateSimple(struct prop *prop, struct coord *pos, RoomNum *rooms, s16 type, s32 playernum)
 {
 	return explosionCreate(prop, pos, rooms, type, playernum, false, NULL, 0, NULL);
 }
 
-bool explosionCreateComplex(struct prop *prop, struct coord *pos, s16 *rooms, s16 type, s32 playernum)
+bool explosionCreateComplex(struct prop *prop, struct coord *pos, RoomNum *rooms, s16 type, s32 playernum)
 {
 	struct coord sp100;
 	struct coord sp88;
 	struct explosiontype *etype;
 	bool makescorch = true;
-	s16 room;
+	RoomNum room;
 	f32 y;
 	struct prop *collisionprop;
 
@@ -232,8 +232,8 @@ void explosionAlertChrs(f32 *radius, struct coord *noisepos)
 #endif
 }
 
-bool explosionCreate(struct prop *sourceprop, struct coord *exppos, s16 *exprooms,
-		s16 type, s32 playernum, bool makescorch, struct coord *arg6, s16 room, struct coord *arg8)
+bool explosionCreate(struct prop *sourceprop, struct coord *exppos, RoomNum *exprooms,
+		s16 type, s32 playernum, bool makescorch, struct coord *arg6, RoomNum room, struct coord *arg8)
 {
 	u32 stack;
 	struct explosion *exp = NULL;
@@ -314,8 +314,8 @@ bool explosionCreate(struct prop *sourceprop, struct coord *exppos, s16 *exproom
 			struct coord portal2bbmax;
 			struct coord spd4;
 			struct coord spc8;
-			s16 otherroom;
-			s16 otherroom2;
+			RoomNum otherroom;
+			RoomNum otherroom2;
 			f32 mult = 1;
 			s32 stack4;
 			s32 portalnum2;
@@ -626,7 +626,7 @@ bool explosionOverlapsProp(struct explosion *exp, struct prop *prop, struct coor
 {
 	bool result = false;
 	s32 i;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	if (exp->type == EXPLOSIONTYPE_HUGE25) {
 		result = true;
diff --git a/src/game/lv.c b/src/game/lv.c
index 0aed98d9d..57a3feb6f 100644
--- a/src/game/lv.c
+++ b/src/game/lv.c
@@ -1607,9 +1607,9 @@ Gfx *lvRender(Gfx *gdl)
 						|| debugIsChrStatsEnabled()
 						|| debug0f11ee40()) {
 #if VERSION < VERSION_NTSC_1_0
-					s16 spc8[21];
-					s16 spb0[11];
-					s16 sp9c[10];
+					RoomNum spc8[21];
+					RoomNum spb0[11];
+					RoomNum sp9c[10];
 					s32 j;
 
 					sp9c[0] = g_Vars.currentplayer->memcamroom;
@@ -2063,7 +2063,7 @@ void lvTick(void)
 					// Check if another player is in a nearby room
 					for (playernum = 0; playernum < PLAYERCOUNT() && !foundnearbychr; playernum++) {
 						if (g_Vars.players[playernum]->isdead == false) {
-							s16 *rooms = g_Vars.players[playernum]->prop->rooms;
+							RoomNum *rooms = g_Vars.players[playernum]->prop->rooms;
 							s32 r;
 
 							for (r = 0; rooms[r] != -1 && !foundnearbychr; r++) {
diff --git a/src/game/mplayer/scenarios.c b/src/game/mplayer/scenarios.c
index 4ee3e806c..e2c144d21 100644
--- a/src/game/mplayer/scenarios.c
+++ b/src/game/mplayer/scenarios.c
@@ -64,10 +64,10 @@ struct mpscenario {
 	Gfx *(*radarextrafunc)(Gfx *gdl);
 	bool (*radarchrfunc)(Gfx **gdl, struct prop *prop);
 	bool (*highlightpropfunc)(struct prop *prop, s32 *colour);
-	bool (*spawnfunc)(f32 arg0, struct coord *pos, s16 *rooms, struct prop *prop, f32 *arg4);
+	bool (*spawnfunc)(f32 arg0, struct coord *pos, RoomNum *rooms, struct prop *prop, f32 *arg4);
 	s32 (*maxteamsfunc)(void);
-	bool (*isroomhighlightedfunc)(s16 room);
-	void (*highlightroomfunc)(s16 room, s32 *arg1, s32 *arg2, s32 *arg3);
+	bool (*isroomhighlightedfunc)(RoomNum room);
+	void (*highlightroomfunc)(RoomNum room, s32 *arg1, s32 *arg2, s32 *arg3);
 	void *unk3c; // never hooked into nor fired
 	void (*readsavefunc)(struct savebuffer *buffer);
 	void (*writesavefunc)(struct savebuffer *buffer);
@@ -791,7 +791,7 @@ bool scenarioHighlightProp(struct prop *prop, s32 *colour)
  *
  * CTC uses this to ensure the chrs spawn near their base.
  */
-f32 scenarioChooseSpawnLocation(f32 chrradius, struct coord *pos, s16 *rooms, struct prop *prop)
+f32 scenarioChooseSpawnLocation(f32 chrradius, struct coord *pos, RoomNum *rooms, struct prop *prop)
 {
 	f32 result;
 
@@ -917,7 +917,7 @@ s32 scenarioGetMaxTeams(void)
 /**
  * This callback is unused.
  */
-bool scenarioIsRoomHighlighted(s16 room)
+bool scenarioIsRoomHighlighted(RoomNum room)
 {
 	if (g_MpScenarios[g_MpSetup.scenario].isroomhighlightedfunc) {
 		return g_MpScenarios[g_MpSetup.scenario].isroomhighlightedfunc(room);
@@ -931,7 +931,7 @@ bool scenarioIsRoomHighlighted(s16 room)
  *
  * Used in CTC for the team bases and in KOH for the hill.
  */
-void scenarioHighlightRoom(s16 room, s32 *arg1, s32 *arg2, s32 *arg3)
+void scenarioHighlightRoom(RoomNum room, s32 *arg1, s32 *arg2, s32 *arg3)
 {
 	if (g_MpScenarios[g_MpSetup.scenario].highlightroomfunc) {
 		g_MpScenarios[g_MpSetup.scenario].highlightroomfunc(room, arg1, arg2, arg3);
@@ -1351,7 +1351,7 @@ void scenarioHandleDroppedToken(struct chrdata *chr, struct prop *prop)
 	struct defaultobj *obj;
 	struct pad pad;
 	Mtxf mtx;
-	s16 rooms[2];
+	RoomNum rooms[2];
 
 	if (g_MpSetup.scenario == MPSCENARIO_CAPTURETHECASE) {
 		for (i = 0; i < ARRAYCOUNT(g_ScenarioData.ctc.tokens); i++) {
diff --git a/src/game/mplayer/scenarios/capturethecase.inc b/src/game/mplayer/scenarios/capturethecase.inc
index 652561aca..b701a69c2 100644
--- a/src/game/mplayer/scenarios/capturethecase.inc
+++ b/src/game/mplayer/scenarios/capturethecase.inc
@@ -457,7 +457,7 @@ void ctcAddPad(s32 *cmd)
 	}
 }
 
-bool ctcChooseSpawnLocation(f32 arg0, struct coord *pos, s16 *rooms, struct prop *prop, f32 *arg4)
+bool ctcChooseSpawnLocation(f32 arg0, struct coord *pos, RoomNum *rooms, struct prop *prop, f32 *arg4)
 {
 	struct chrdata *chr = prop->chr;
 	s32 index = radarGetTeamIndex(chr->team);
@@ -477,7 +477,7 @@ s32 ctcGetMaxTeams(void)
 	return 4;
 }
 
-bool ctcIsRoomHighlighted(s16 room)
+bool ctcIsRoomHighlighted(RoomNum room)
 {
 	s32 i;
 
@@ -490,7 +490,7 @@ bool ctcIsRoomHighlighted(s16 room)
 	return false;
 }
 
-void ctcHighlightRoom(s16 roomnum, s32 *arg1, s32 *arg2, s32 *arg3)
+void ctcHighlightRoom(RoomNum roomnum, s32 *arg1, s32 *arg2, s32 *arg3)
 {
 	s32 i;
 
diff --git a/src/game/mplayer/scenarios/kingofthehill.inc b/src/game/mplayer/scenarios/kingofthehill.inc
index ae926e975..2a837ff23 100644
--- a/src/game/mplayer/scenarios/kingofthehill.inc
+++ b/src/game/mplayer/scenarios/kingofthehill.inc
@@ -658,12 +658,12 @@ void kohAddHill(s32 *cmd)
 	}
 }
 
-bool kohIsRoomHighlighted(s16 room)
+bool kohIsRoomHighlighted(RoomNum room)
 {
 	return room == g_ScenarioData.koh.hillrooms[0];
 }
 
-void kohHighlightRoom(s16 roomnum, s32 *arg1, s32 *arg2, s32 *arg3)
+void kohHighlightRoom(RoomNum roomnum, s32 *arg1, s32 *arg2, s32 *arg3)
 {
 	if (roomnum == g_ScenarioData.koh.hillrooms[0]) {
 		f32 a = *arg1;
diff --git a/src/game/nbomb.c b/src/game/nbomb.c
index c38e0265d..9ef9e2839 100644
--- a/src/game/nbomb.c
+++ b/src/game/nbomb.c
@@ -431,7 +431,7 @@ void nbombInflictDamage(struct nbomb *nbomb)
 	s16 propnums[256];
 	struct coord bbmin;
 	struct coord bbmax;
-	s16 roomnums[54];
+	RoomNum roomnums[54];
 	s16 *propnumptr;
 	s32 i;
 	struct gset gset;
diff --git a/src/game/objectives.c b/src/game/objectives.c
index 7cc60ae29..61e147e26 100644
--- a/src/game/objectives.c
+++ b/src/game/objectives.c
@@ -455,7 +455,7 @@ void objectiveCheckRoomEntered(s32 currentroom)
 	}
 }
 
-void objectiveCheckThrowInRoom(s32 arg0, s16 *inrooms)
+void objectiveCheckThrowInRoom(s32 arg0, RoomNum *inrooms)
 {
 	struct criteria_throwinroom *criteria = g_ThrowInRoomCriterias;
 
@@ -464,7 +464,7 @@ void objectiveCheckThrowInRoom(s32 arg0, s16 *inrooms)
 			s32 room = chrGetPadRoom(NULL, criteria->pad);
 
 			if (room >= 0) {
-				s16 requirerooms[2];
+				RoomNum requirerooms[2];
 				requirerooms[0] = room;
 				requirerooms[1] = -1;
 
diff --git a/src/game/padhalllv.c b/src/game/padhalllv.c
index 20f1f24b8..7d55e2be9 100644
--- a/src/game/padhalllv.c
+++ b/src/game/padhalllv.c
@@ -73,12 +73,12 @@ void navSetSeed(u32 upper, u32 lower)
  * The function will return NULL if there are no waypoints at all within the
  * position's room or its neighbours.
  */
-struct waypoint *waypointFindClosestToPos(struct coord *pos, s16 *rooms)
+struct waypoint *waypointFindClosestToPos(struct coord *pos, RoomNum *rooms)
 {
 	struct waypoint *closest = NULL;
-	s16 allrooms[30];
+	RoomNum allrooms[30];
 	s32 candlen = 0;
-	s16 neighbours[10];
+	RoomNum neighbours[10];
 	s32 i;
 	s32 j;
 	struct waypoint *candwaypoints[10];
@@ -152,7 +152,7 @@ struct waypoint *waypointFindClosestToPos(struct coord *pos, s16 *rooms)
 		// Check which candidates have line of sight
 		for (i = 0; i < candlen; i++) {
 			struct pad pad;
-			s16 padrooms[8];
+			RoomNum padrooms[8];
 
 			padUnpack(candwaypoints[i]->padnum, PADFIELD_POS | PADFIELD_ROOM, &pad);
 
@@ -185,10 +185,10 @@ struct waypoint *waypointFindClosestToPos(struct coord *pos, s16 *rooms)
 			for (i = 0; i < candlen; i++) {
 				if (checkmore[i] && (sp250[i].x != sp1d8[i].x || sp250[i].z != sp1d8[i].z)) {
 					struct pad pad;
-					s16 padrooms[8];
+					RoomNum padrooms[8];
 					struct coord sp98;
 					struct coord tmppos;
-					s16 tmprooms[8];
+					RoomNum tmprooms[8];
 					f32 mult;
 
 					padUnpack(candwaypoints[i]->padnum, PADFIELD_POS | PADFIELD_ROOM, &pad);
diff --git a/src/game/player.c b/src/game/player.c
index b3de7af4e..0e7278e30 100644
--- a/src/game/player.c
+++ b/src/game/player.c
@@ -211,7 +211,7 @@ s32 g_NumDeathAnimations = 0;
  * @dangerous: If there are too many pads (24+) in the setup then array
  * overflows may occur.
  */
-f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, s16 *dstrooms, struct prop *prop, s16 *pads, s32 numpads)
+f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, RoomNum *dstrooms, struct prop *prop, s16 *pads, s32 numpads)
 {
 	u8 verybadpads[24];
 	u8 badpads[24];
@@ -226,7 +226,7 @@ f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, s16 *dstrooms
 	// "sl" prefixes are for shortlist
 	s16 slpadindexes[8];
 	struct coord slpositions[4];
-	s16 slrooms[4][8];
+	RoomNum slrooms[4][8];
 	f32 slangles[4];
 	s32 sllen = 0;
 
@@ -237,9 +237,9 @@ f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, s16 *dstrooms
 	u8 stack2[0x10];
 	struct pad pad;
 	s32 stack3[2];
-	s16 tmppadrooms[2];
+	RoomNum tmppadrooms[2];
 	f32 bestsqdist;
-	s16 neighbours[20];
+	RoomNum neighbours[20];
 
 	// Iterate all spawn pads and populate the category arrays
 	for (p = 0; p < numpads; p++) {
@@ -472,7 +472,7 @@ f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, s16 *dstrooms
 	return dstangle;
 }
 
-f32 playerChooseGeneralSpawnLocation(f32 chrradius, struct coord *pos, s16 *rooms, struct prop *prop)
+f32 playerChooseGeneralSpawnLocation(f32 chrradius, struct coord *pos, RoomNum *rooms, struct prop *prop)
 {
 	return playerChooseSpawnLocation(chrradius, pos, rooms, prop, g_SpawnPoints, g_NumSpawnPoints);
 }
@@ -480,7 +480,7 @@ f32 playerChooseGeneralSpawnLocation(f32 chrradius, struct coord *pos, s16 *room
 void playerStartNewLife(void)
 {
 	struct coord pos = {0, 0, 0};
-	s16 rooms[8];
+	RoomNum rooms[8];
 	f32 angle;
 	s32 *cmd = g_StageSetup.intro;
 	f32 groundy;
@@ -3366,9 +3366,9 @@ void playerTick(bool arg0)
 					rocket->base.realrot[0][0] * rocket->base.realrot[0][0] +
 					rocket->base.realrot[1][0] * rocket->base.realrot[1][0] +
 					rocket->base.realrot[2][0] * rocket->base.realrot[2][0]);
-			s16 inrooms[21];
-			s16 aboverooms[21];
-			s16 bestroom;
+			RoomNum inrooms[21];
+			RoomNum aboverooms[21];
+			RoomNum bestroom;
 			s16 outofbounds = false;
 
 			sp2b8[0][0] = rocket->base.realrot[0][0] / sp2a8;
@@ -4921,14 +4921,14 @@ void playerSetCameraMode(s32 mode)
 	g_Vars.currentplayer->cameramode = mode;
 }
 
-void player0f0c1840(struct coord *pos, struct coord *up, struct coord *look, struct coord *pos2, s16 *rooms2)
+void player0f0c1840(struct coord *pos, struct coord *up, struct coord *look, struct coord *pos2, RoomNum *rooms2)
 {
 	bool done = false;
-	s16 inrooms[21];
-	s16 aboverooms[21];
-	s16 sp54[8];
-	s16 bestroom;
-	s16 tmp;
+	RoomNum inrooms[21];
+	RoomNum aboverooms[21];
+	RoomNum sp54[8];
+	RoomNum bestroom;
+	RoomNum tmp;
 	s32 i;
 	s32 room;
 
@@ -5022,7 +5022,7 @@ void player0f0c1840(struct coord *pos, struct coord *up, struct coord *look, str
 
 void player0f0c1ba4(struct coord *pos, struct coord *up, struct coord *look, struct coord *memcampos, s32 memcamroom)
 {
-	s16 rooms[2];
+	RoomNum rooms[2];
 	rooms[0] = memcamroom;
 	rooms[1] = -1;
 
diff --git a/src/game/playerreset.c b/src/game/playerreset.c
index 0e786b62c..aed9245f3 100644
--- a/src/game/playerreset.c
+++ b/src/game/playerreset.c
@@ -110,7 +110,7 @@ struct cmd32 {
 void playerReset(void)
 {
 	struct coord pos = {0, 0, 0};
-	s16 rooms[8];
+	RoomNum rooms[8];
 	f32 turnanglerad = 0;
 	f32 groundy;
 	bool hasdefaultweapon = false;
diff --git a/src/game/prop.c b/src/game/prop.c
index 12360bc08..2a0c496f3 100644
--- a/src/game/prop.c
+++ b/src/game/prop.c
@@ -391,11 +391,11 @@ Gfx *propRender(Gfx *gdl, struct prop *prop, bool xlupass)
  * terminal in the pre-bg pass and the screen in the post-bg pass, likely to
  * avoid Z-fighting issues.
  */
-Gfx *propsRender(Gfx *gdl, s16 renderroomnum, s32 renderpass, s16 *roomnumsbyprop)
+Gfx *propsRender(Gfx *gdl, RoomNum renderroomnum, s32 renderpass, RoomNum *roomnumsbyprop)
 {
 	struct prop **ptr;
 	struct prop *prop;
-	s16 *proprooms;
+	RoomNum *proprooms;
 
 	if (renderpass == RENDERPASS_OPA_PREBG || renderpass == RENDERPASS_OPA_POSTBG) {
 		// Iterate onscreen props near to far
@@ -592,22 +592,22 @@ struct prop *shotCalculateHits(s32 handnum, bool arg1, struct coord *arg2, struc
 	s32 sparktype;
 
 #ifdef AVOID_UB
-	s16 rooms[131];
+	RoomNum rooms[131];
 #else
-	s16 rooms[124];
+	RoomNum rooms[124];
 #endif
 
-	s16 spc8[8];
-	s16 spb8[8];
+	RoomNum spc8[8];
+	RoomNum spb8[8];
 	s32 uVar6;
-	s16 *roomsptr;
+	RoomNum *roomsptr;
 	struct prop *prop;
 	struct coord spa0;
 	struct defaultobj *obj;
 	bool doexplosiveshells;
 	struct coord sp8c;
-	s16 sp7c[8];
-	s16 sp6c[8];
+	RoomNum sp7c[8];
+	RoomNum sp6c[8];
 	struct prop *hitprop;
 
 	bgun0f0a9494(arg6);
@@ -1688,7 +1688,7 @@ void propsTickPlayer(bool islastplayer)
 	s32 savedslotupdate240_60;
 	f32 savedslotupdate240f;
 	struct g_vars *vars = &g_Vars;
-	s16 *rooms;
+	RoomNum *rooms;
 	u8 mostindex;
 	u8 leastindex;
 	u8 runstateindex;
@@ -2215,8 +2215,8 @@ void propsTickPadEffects(void)
 	struct pad pad;
 	u32 stack;
 	struct coord up;
-	s16 rooms[2];
-	s16 rooms2[2];
+	RoomNum rooms[2];
+	RoomNum rooms2[2];
 	s32 type;
 
 	if (g_LastPadEffectIndex >= 0) {
@@ -2306,8 +2306,8 @@ void propsTestForPickup(void)
 	s16 *propnumptr;
 	s32 i;
 	s16 propnums[256];
-	s16 allrooms[21];
-	s16 tmp[11];
+	RoomNum allrooms[21];
+	RoomNum tmp[11];
 
 	if (g_Vars.currentplayer->bondmovemode != MOVEMODE_CUTSCENE
 			&& !g_PlayerInvincible
@@ -2853,10 +2853,10 @@ bool propIsOfCdType(struct prop *prop, u32 types)
 	return result;
 }
 
-void roomsCopy(s16 *src, s16 *dst)
+void roomsCopy(RoomNum *src, RoomNum *dst)
 {
-	s16 *srcptr = src;
-	s16 *dstptr = dst;
+	RoomNum *srcptr = src;
+	RoomNum *dstptr = dst;
 	s32 val;
 
 	while ((val = *srcptr) != -1) {
@@ -2871,7 +2871,7 @@ void roomsCopy(s16 *src, s16 *dst)
 /**
  * Append newrooms to dstrooms without duplicates.
  */
-void roomsAppend(s16 *newrooms, s16 *dstrooms, s32 maxlen)
+void roomsAppend(RoomNum *newrooms, RoomNum *dstrooms, s32 maxlen)
 {
 	s32 i;
 
@@ -2887,12 +2887,12 @@ void roomsAppend(s16 *newrooms, s16 *dstrooms, s32 maxlen)
 	}
 }
 
-bool arrayIntersects(s16 *a, s16 *b)
+bool arrayIntersects(RoomNum *a, RoomNum *b)
 {
-	s16 *aptr = a;
-	s16 aval = *aptr;
-	s16 *bptr;
-	s16 bval;
+	RoomNum *aptr = a;
+	RoomNum aval = *aptr;
+	RoomNum *bptr;
+	RoomNum bval;
 
 	while (aval != -1) {
 		bptr = b; bval = *bptr;
@@ -2951,7 +2951,7 @@ s32 roomAllocatePropListChunk(s32 room, s32 prevchunkindex)
 	return -1;
 }
 
-void propRegisterRoom(struct prop *prop, s16 room)
+void propRegisterRoom(struct prop *prop, RoomNum room)
 {
 	s32 prev = -1;
 	s32 i;
@@ -2979,7 +2979,7 @@ void propRegisterRoom(struct prop *prop, s16 room)
 	}
 }
 
-void propDeregisterRoom(struct prop *prop, s16 room)
+void propDeregisterRoom(struct prop *prop, RoomNum room)
 {
 	bool removed = false;
 	s32 prev = -1;
@@ -3033,8 +3033,8 @@ void propDeregisterRoom(struct prop *prop, s16 room)
  */
 void propDeregisterRooms(struct prop *prop)
 {
-	s16 *rooms = prop->rooms;
-	s16 room = *rooms;
+	RoomNum *rooms = prop->rooms;
+	RoomNum room = *rooms;
 
 	while (room != -1) {
 		propDeregisterRoom(prop, room);
@@ -3050,8 +3050,8 @@ void propDeregisterRooms(struct prop *prop)
  */
 void propRegisterRooms(struct prop *prop)
 {
-	s16 *rooms = prop->rooms;
-	s16 room = *rooms;
+	RoomNum *rooms = prop->rooms;
+	RoomNum room = *rooms;
 
 	while (room != -1) {
 		propRegisterRoom(prop, room);
@@ -3060,9 +3060,9 @@ void propRegisterRooms(struct prop *prop)
 	}
 }
 
-void func0f065d1c(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms, s16 *morerooms, u32 arg5)
+void func0f065d1c(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms, RoomNum *morerooms, u32 arg5)
 {
-	s16 stackrooms[8];
+	RoomNum stackrooms[8];
 	s32 index;
 	s32 i;
 
@@ -3080,12 +3080,12 @@ void func0f065d1c(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newr
 	newrooms[index] = -1;
 }
 
-void func0f065dd8(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms)
+void func0f065dd8(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms)
 {
 	func0f065d1c(pos, rooms, newpos, newrooms, NULL, 0);
 }
 
-void func0f065dfc(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms, s16 *morerooms, u32 arg5)
+void func0f065dfc(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms, RoomNum *morerooms, u32 arg5)
 {
 	func0f065d1c(pos, rooms, newpos, newrooms, morerooms, arg5);
 
@@ -3098,16 +3098,16 @@ void func0f065dfc(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newr
 	}
 }
 
-void func0f065e74(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms)
+void func0f065e74(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms)
 {
 	func0f065dfc(pos, rooms, newpos, newrooms, NULL, 0);
 }
 
-void func0f065e98(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *dstrooms)
+void func0f065e98(struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *dstrooms)
 {
-	s16 inrooms[21];
-	s16 aboverooms[21];
-	s16 *ptr = NULL;
+	RoomNum inrooms[21];
+	RoomNum aboverooms[21];
+	RoomNum *ptr = NULL;
 	s32 i;
 
 	bgFindRoomsByPos(pos2, inrooms, aboverooms, 20, NULL);
@@ -3148,10 +3148,10 @@ void func0f065e98(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *dstroo
  * to get 256 props in a small space without exhausing the memory of the
  * console, you could potentially achieve arbitrary code execution.
  */
-void roomGetProps(s16 *rooms, s16 *propnums, s32 len)
+void roomGetProps(RoomNum *rooms, s16 *propnums, s32 len)
 {
 	s16 *writeptr = propnums;
-	s32 room;
+	RoomNum room;
 	s32 i;
 	s32 j;
 
diff --git a/src/game/propobj.c b/src/game/propobj.c
index 198b84644..ff0392a62 100644
--- a/src/game/propobj.c
+++ b/src/game/propobj.c
@@ -989,7 +989,7 @@ struct defaultobj *objFindByPadNum(s32 padnum)
 	return NULL;
 }
 
-struct defaultobj *objFindByPos(struct coord *pos, s16 *rooms)
+struct defaultobj *objFindByPos(struct coord *pos, RoomNum *rooms)
 {
 	struct prop *prop = g_Vars.activeprops;
 	u8 *sp38;
@@ -1353,7 +1353,7 @@ struct modelrodata_bbox *objFindBboxRodata(struct defaultobj *obj)
 	return modelFindBboxRodata(obj->model);
 }
 
-s32 objGetAverageBrightnessInRooms(s16 *rooms, s32 brightnesstype)
+s32 objGetAverageBrightnessInRooms(RoomNum *rooms, s32 brightnesstype)
 {
 	s32 brightness = 0;
 	s32 i;
@@ -2142,7 +2142,7 @@ struct prop *objInitWithAutoModel(struct defaultobj *obj)
 	return objInitWithModelDef(obj, g_ModelStates[obj->modelnum].modeldef);
 }
 
-void func0f06a580(struct defaultobj *obj, struct coord *pos, Mtxf *matrix, s16 *rooms)
+void func0f06a580(struct defaultobj *obj, struct coord *pos, Mtxf *matrix, RoomNum *rooms)
 {
 	struct prop *prop = obj->prop;
 
@@ -2171,13 +2171,13 @@ f32 func0f06a620(struct defaultobj *obj)
 	return 4;
 }
 
-void func0f06a650(struct defaultobj *obj, struct coord *pos, Mtxf *arg2, s16 *rooms)
+void func0f06a650(struct defaultobj *obj, struct coord *pos, Mtxf *arg2, RoomNum *rooms)
 {
 	struct modelrodata_bbox *bbox;
-	s16 room;
+	RoomNum room;
 	f32 sp3c;
 	struct coord newpos;
-	s16 newrooms[2];
+	RoomNum newrooms[2];
 
 	bbox = modelFindBboxRodata(obj->model);
 
@@ -2201,14 +2201,14 @@ void func0f06a650(struct defaultobj *obj, struct coord *pos, Mtxf *arg2, s16 *ro
 	}
 }
 
-void func0f06a730(struct defaultobj *obj, struct coord *arg1, Mtxf *mtx, s16 *rooms, struct coord *centre)
+void func0f06a730(struct defaultobj *obj, struct coord *arg1, Mtxf *mtx, RoomNum *rooms, struct coord *centre)
 {
 	struct modelrodata_bbox *bbox = modelFindBboxRodata(obj->model);
 	f32 min = objGetLocalYMin(bbox);
 	f32 max = objGetLocalYMax(bbox);
 	struct coord pos2;
 	Mtxf sp70;
-	s16 rooms2[8];
+	RoomNum rooms2[8];
 	f32 curval;
 	f32 y;
 	f32 maxval;
@@ -2327,12 +2327,12 @@ void func0f06a730(struct defaultobj *obj, struct coord *arg1, Mtxf *mtx, s16 *ro
 	func0f06a580(obj, &pos2, &sp70, rooms2);
 }
 
-void func0f06ab60(struct defaultobj *obj, struct coord *arg1, Mtxf *arg2, s16 *rooms, struct coord *arg4)
+void func0f06ab60(struct defaultobj *obj, struct coord *arg1, Mtxf *arg2, RoomNum *rooms, struct coord *arg4)
 {
 	struct modelrodata_bbox *bbox;
 	f32 mult;
 	struct coord newpos;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	Mtxf sp5c;
 	Mtxf sp1c;
 
@@ -3108,7 +3108,7 @@ bool func0f06c28c(struct chrdata *chr, struct coord *arg1, struct coord *arg2, s
 	return result;
 }
 
-bool projectileFindCollidingProp(struct prop *prop, struct coord *pos1, struct coord *pos2, u32 cdtypes, struct coord *arg4, struct coord *arg5, s16 *rooms)
+bool projectileFindCollidingProp(struct prop *prop, struct coord *pos1, struct coord *pos2, u32 cdtypes, struct coord *arg4, struct coord *arg5, RoomNum *rooms)
 {
 	bool result = false;
 	f32 dist;
@@ -3232,9 +3232,9 @@ s32 func0f06cd00(struct defaultobj *obj, struct coord *pos, struct coord *arg2,
 	struct coord sp1c4;
 	u32 stack;
 	bool s0;
-	s16 spcc[120];
-	s16 *ptr;
-	s16 spb8[8];
+	RoomNum spcc[120];
+	RoomNum *ptr;
+	RoomNum spb8[8];
 	s32 i;
 	f32 scale = 1.0f;
 
@@ -3287,7 +3287,7 @@ s32 func0f06cd00(struct defaultobj *obj, struct coord *pos, struct coord *arg2,
 					}
 				}
 			} else {
-				s16 spa0[2];
+				RoomNum spa0[2];
 				spa0[0] = spcc[i];
 				spa0[1] = -1;
 
@@ -3377,7 +3377,7 @@ bool func0f06d37c(struct defaultobj *obj, struct coord *arg1, struct coord *arg2
 	bool sp98 = false;
 	struct coord sp8c;
 	struct coord sp80;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct coord sp64;
 	struct coord sp58;
 	struct coord sp4c;
@@ -3966,7 +3966,7 @@ void objLand2(struct defaultobj *obj, struct coord *arg1, struct coord *arg2)
 	struct modelrodata_bbox *bbox = modelFindBboxRodata(obj->model);
 	f32 ymin = objGetLocalYMin(bbox);
 	struct prop *prop = obj->prop;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 
 	func0f06e9cc(arg2, &sp40);
 	mtx00015f04(obj->model->scale, &sp40);
@@ -3987,7 +3987,7 @@ void boltLand(struct weaponobj *weapon, struct coord *arg1)
 	s32 beamnum;
 	f32 zmax;
 	struct prop *prop;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 
 	bbox = modelFindBboxRodata(weapon->base.model);
 	prop = weapon->base.prop;
@@ -4023,7 +4023,7 @@ void knifeLand(struct defaultobj *obj, struct coord *arg1, struct coord *arg2)
 	struct modelrodata_bbox *bbox = modelFindBboxRodata(obj->model);
 	f32 zero = 0.0f;
 	struct prop *prop = obj->prop;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	struct coord sp1c;
 
 	// @bug? Should these be assigned to zero?
@@ -4175,7 +4175,7 @@ bool propExplode(struct prop *prop, s32 exptype)
 	if (prop->parent) {
 		struct prop *parent = prop->parent;
 		struct coord pos;
-		s16 rooms[8];
+		RoomNum rooms[8];
 
 		while (parent->parent) {
 			parent = parent->parent;
@@ -5159,10 +5159,10 @@ f32 objGetHov04(struct defaultobj *obj)
 	return result;
 }
 
-void hovUpdateGround(struct defaultobj *obj, struct hov *hov, struct coord *pos, s16 *rooms, f32 matrix[3][3])
+void hovUpdateGround(struct defaultobj *obj, struct hov *hov, struct coord *pos, RoomNum *rooms, f32 matrix[3][3])
 {
 	f32 ground;
-	s16 testrooms[8];
+	RoomNum testrooms[8];
 	struct coord testpos;
 
 	if (g_Vars.lvframe60 > hov->nexttick60) {
@@ -5194,8 +5194,8 @@ void hovTick(struct defaultobj *obj, struct hov *hov)
 	struct modelrodata_bbox *bbox;
 	struct coord sp1b4;
 	struct coord sp1a8;
-	s16 sp198[8];
-	s16 sp188[8];
+	RoomNum sp198[8];
+	RoomNum sp188[8];
 	Mtxf sp148;
 	Mtxf sp108;
 	Mtxf spc8;
@@ -5206,7 +5206,7 @@ void hovTick(struct defaultobj *obj, struct hov *hov)
 	f32 spb4;
 	f32 xrot;
 	f32 spac;
-	s16 sp9c[8];
+	RoomNum sp9c[8];
 	struct coord sp90;
 	bool sp8c;
 	f32 radius;
@@ -5481,7 +5481,7 @@ s32 func0f072144(struct defaultobj *obj, struct coord *arg1, f32 arg2, bool arg3
 	f32 sp460[3][3];
 	f32 yrot;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct hov prevhov;
 	struct hov *hov = NULL;
 	union geounion geounion;
@@ -5632,7 +5632,7 @@ void hovercarStartNextPath(struct hovercarobj *hovercar)
 	s32 *pads;
 	struct pad pad;
 	Mtxf matrix;
-	s16 rooms[2];
+	RoomNum rooms[2];
 
 	hovercarFindNextPath(hovercar);
 
@@ -6008,7 +6008,7 @@ bool rocketTickFbw(struct weaponobj *rocket)
 	struct coord newpos;
 	struct coord dir;
 	u32 stack[2];
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 
 	if (projectile->ownerprop && projectile->ownerprop->type == PROPTYPE_CHR) {
 		ownerchr = projectile->ownerprop->chr;
@@ -6185,7 +6185,7 @@ s32 projectileLaunch(struct defaultobj *obj, struct projectile *projectile, stru
 	}
 
 	if (cdresult == CDRESULT_NOCOLLISION) {
-		s16 rooms[8];
+		RoomNum rooms[8];
 
 		func0f065e74(&prop->pos, prop->rooms, &projectile->nextsteppos, rooms);
 
@@ -6197,7 +6197,7 @@ s32 projectileLaunch(struct defaultobj *obj, struct projectile *projectile, stru
 		roomsCopy(rooms, prop->rooms);
 	} else if (cdresult != CDRESULT_NOCOLLISION && obj->type == OBJTYPE_WEAPON) {
 		struct weaponobj *weapon = (struct weaponobj *)obj;
-		s16 rooms[8];
+		RoomNum rooms[8];
 
 		if (weapon->weaponnum == WEAPON_ROCKET || weapon->weaponnum == WEAPON_HOMINGROCKET) {
 			weapon->timer240 = 0;
@@ -6228,7 +6228,7 @@ s32 projectileTick(struct defaultobj *obj, bool *embedded)
 	bool result = false;
 	struct prop *prop = obj->prop;
 	struct coord sp5c8;
-	s16 sp5b8[8];
+	RoomNum sp5b8[8];
 	struct coord sp5ac;
 	f32 sp5a8;
 	struct coord sp59c;
@@ -6662,7 +6662,7 @@ s32 projectileTick(struct defaultobj *obj, bool *embedded)
 				result = true;
 			} else if (projectile->flags & PROJECTILEFLAG_AIRBORNE) {
 				f32 sp390;
-				s16 roomnum;
+				RoomNum roomnum;
 				struct coord sp380;
 				f32 sp37c;
 				f32 realrot[3][3];
@@ -7147,7 +7147,7 @@ s32 projectileTick(struct defaultobj *obj, bool *embedded)
 
 					if (!handled) {
 						if (cdresult != CDRESULT_COLLISION) {
-							s16 rooms[8];
+							RoomNum rooms[8];
 
 							func0f065e74(&prop->pos, prop->rooms, &sp5dc, rooms);
 
@@ -7158,7 +7158,7 @@ s32 projectileTick(struct defaultobj *obj, bool *embedded)
 							propDeregisterRooms(prop);
 							roomsCopy(rooms, prop->rooms);
 						} else {
-							s16 rooms[8];
+							RoomNum rooms[8];
 
 							if (g_EmbedProp && (g_EmbedProp->type == PROPTYPE_CHR || g_EmbedProp->type == PROPTYPE_PLAYER)) {
 								sp5dc.x = prop->pos.x;
@@ -7444,7 +7444,7 @@ s32 projectileTick(struct defaultobj *obj, bool *embedded)
 				if (projectile->speed.f[0] != 0.0f || projectile->speed.f[2] != 0.0f || projectile->unk060 < 1.0f) {
 					f32 f12;
 					f32 spa4;
-					s16 roomnum;
+					RoomNum roomnum;
 					s32 i;
 					f32 sp98 = objGetRotatedLocalYMinByMtx3(objFindBboxRodata(obj), obj->realrot);
 #if VERSION >= VERSION_NTSC_1_0
@@ -7882,7 +7882,7 @@ void platformDisplaceProps(struct prop *platform, s16 *propnums, struct coord *p
 
 					if (g_Vars.players[playernum]->inlift && !g_Vars.players[playernum]->onladder && !g_Vars.players[playernum]->isfalling) {
 						struct coord sp78;
-						s16 sp68[8];
+						RoomNum sp68[8];
 						f32 ydist = newpos->y - prevpos->y;
 
 						if (ydist != 0.0f) {
@@ -7975,7 +7975,7 @@ void liftTick(struct prop *prop)
 	f32 frac;
 	s32 move;
 	struct coord newpos;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	struct coord prevpos;
 #if VERSION >= VERSION_NTSC_1_0
 	f32 prevdist;
@@ -9009,11 +9009,11 @@ void autogunTickShoot(struct prop *autogunprop)
 
 			if (fireleft || fireright) {
 				struct coord gunpos;
-				s16 gunrooms[8];
+				RoomNum gunrooms[8];
 				struct coord dir;
 				bool missed = false;
 				struct coord hitpos;
-				s16 hitrooms[8];
+				RoomNum hitrooms[8];
 				bool makebeam = (autogun->firecount % 4) == 0;
 				struct prop *targetprop = autogun->target;
 				struct modelnode *flashnode;
@@ -9773,7 +9773,7 @@ void chopperIncrementMovement(struct prop *prop, f32 goalroty, f32 goalrotx, str
 {
 	struct defaultobj *obj = prop->obj;
 	struct chopperobj *chopper = (struct chopperobj *)obj;
-	s16 newrooms[8];
+	RoomNum newrooms[8];
 	struct coord newpos;
 	f32 curroty;
 	f32 currotx;
@@ -10066,10 +10066,10 @@ void chopperTickFall(struct prop *chopperprop)
 
 		if (cdExamLos09(&chopperprop->pos, chopperprop->rooms, &newpos, CDTYPE_BG) == CDRESULT_COLLISION) {
 			struct coord sp74;
-			s16 room;
+			RoomNum room;
 			struct coord sp64;
 			f32 ground;
-			s16 newrooms[8];
+			RoomNum newrooms[8];
 
 			chopperprop->pos.y += 100;
 			ground = cdFindGroundAtCyl(&chopperprop->pos, 5, chopperprop->rooms, NULL, NULL);
@@ -10369,7 +10369,7 @@ void hovercarTick(struct prop *prop)
 	bool stopping;
 	struct pad pad;
 	struct coord sp214;
-	s16 sp210[2];
+	RoomNum sp210[2];
 	struct hovercarobj *hovercar = (struct hovercarobj *) prop->obj;
 	struct defaultobj *obj = &hovercar->base;
 	u32 stack;
@@ -10380,11 +10380,11 @@ void hovercarTick(struct prop *prop)
 	struct prop *doorprop;
 	struct coord sp1e4;
 	struct coord sp1d8;
-	s16 sp1d6;
+	RoomNum sp1d6;
 	f32 x;
 	f32 z;
 	struct coord sp1c0;
-	s16 sp1b0[8];
+	RoomNum sp1b0[8];
 	struct modelrodata_bbox *bbox;
 	f32 ymin;
 	s32 *padnum;
@@ -10397,7 +10397,7 @@ void hovercarTick(struct prop *prop)
 	f32 sp180;
 	f32 sp15c[3][3];
 	struct coord sp150;
-	s16 sp140[8];
+	RoomNum sp140[8];
 	f32 tmp2;
 	f32 sp138;
 	struct coord sp12c;
@@ -11026,7 +11026,7 @@ s32 objTickPlayer(struct prop *prop)
 				struct modelrenderdata sp476 = {0, 1, 3};
 				Mtxf sp412;
 				struct coord sp400;
-				s16 sp384[8];
+				RoomNum sp384[8];
 				struct hov *hov = NULL;
 
 				if (fulltick) {
@@ -11112,7 +11112,7 @@ s32 objTickPlayer(struct prop *prop)
 			struct modelrenderdata sp312 = {0, 1, 3};
 			Mtxf sp248;
 			struct coord sp236;
-			s16 sp220[8];
+			RoomNum sp220[8];
 			s32 numchrs;
 			Mtxf sp152;
 			s32 sp148;
@@ -14387,7 +14387,7 @@ bool objDrop(struct prop *prop, bool lazy)
 	struct model *model;
 	Mtxf spf0;
 	struct coord spe4;
-	s16 rooms[8];
+	RoomNum rooms[8];
 
 	if ((obj->hidden & OBJHFLAG_EMBEDDED) && obj->embedment->projectile) {
 		struct projectile *projectile2 = obj->embedment->projectile;
@@ -14704,7 +14704,7 @@ void objCheckDestroyed(struct defaultobj *obj, struct coord *pos, s32 playernum)
 		struct prop *prop = obj->prop;
 		struct prop *rootprop = prop;
 		s16 exptype = g_PropExplosionTypes[8 + obj->modelnum];
-		s16 rooms[8];
+		RoomNum rooms[8];
 
 		// If in Deep Sea outro
 		if (g_Vars.tickmode == TICKMODE_CUTSCENE && g_CutsceneAnimNum == ANIM_CUT_PAM_OUTRO_CAM) {
@@ -18761,7 +18761,7 @@ s32 weaponTestForPickup(struct prop *prop)
 	return objTestForPickup(prop);
 }
 
-void weaponSetGunfireVisible(struct prop *prop, bool visible, s16 room)
+void weaponSetGunfireVisible(struct prop *prop, bool visible, RoomNum room)
 {
 	u32 stack[4];
 	bool flash = false;
@@ -19297,12 +19297,12 @@ void doorDeactivatePortal(struct doorobj *door)
 	}
 }
 
-struct prop *doorInit(struct doorobj *door, struct coord *pos, Mtxf *mtx, s16 *rooms, struct coord *coord, struct coord *centre)
+struct prop *doorInit(struct doorobj *door, struct coord *pos, Mtxf *mtx, RoomNum *rooms, struct coord *coord, struct coord *centre)
 {
 	struct prop *prop;
 	union modelrodata *rodata;
 	Mtxf sp38;
-	s16 sp28[8];
+	RoomNum sp28[8];
 
 	door->base.flags |= OBJFLAG_00000100;
 	prop = objInitWithAutoModel(&door->base);
@@ -19805,10 +19805,10 @@ s32 doorIsOpen(struct doorobj *door)
 	return (door->mode == DOORMODE_IDLE || door->mode == DOORMODE_WAITING) && door->frac >= door->maxfrac;
 }
 
-s32 func0f08e5a8(s16 *rooms2, struct screenbox *box)
+s32 func0f08e5a8(RoomNum *rooms2, struct screenbox *box)
 {
 	bool result = false;
-	s16 *rooms = rooms2;
+	RoomNum *rooms = rooms2;
 	s32 roomnum = *rooms;
 
 	while (roomnum != -1) {
@@ -19913,8 +19913,8 @@ bool posIsInObjFadeDistance(struct coord *pos, f32 modelscale)
 
 bool func0f08e8ac(struct prop *prop, struct coord *pos, f32 arg2, bool arg3)
 {
-	s16 *rooms;
-	s32 roomnum;
+	RoomNum *rooms;
+	RoomNum roomnum;
 	bool result = false;
 	u32 stack;
 
@@ -21123,7 +21123,7 @@ void projectileCreate(struct prop *fromprop, struct fireslotthing *arg1, struct
 		f32 z;
 		f32 sqdist;
 		struct prop *obstacle = NULL;
-		s16 sp1c8[8];
+		RoomNum sp1c8[8];
 		u8 forcebeam = false;
 		struct beam beam;
 		struct coord frompos;
diff --git a/src/game/propsnd.c b/src/game/propsnd.c
index 9e4b07fde..6cd41bd3c 100644
--- a/src/game/propsnd.c
+++ b/src/game/propsnd.c
@@ -232,7 +232,7 @@ void psTickChannel(s32 channelnum)
 #endif
 	{
 		struct coord *pos = NULL;
-		s16 *rooms = NULL;
+		RoomNum *rooms = NULL;
 		s32 newvol;
 		s32 newpan;
 		s32 newfx;
@@ -261,7 +261,7 @@ void psTickChannel(s32 channelnum)
 			}
 		} else {
 			if (pos && rooms) {
-				s16 *tmprooms;
+				RoomNum *tmprooms;
 
 				if (channel->flags & PSFLAG_IGNOREROOMS) {
 					tmprooms = NULL;
@@ -645,7 +645,7 @@ void psStopOneShootChannel(struct prop *prop)
 
 s16 psCreate(struct pschannel *channel, struct prop *prop, s16 soundnum, s16 padnum,
 		s32 vol, u16 flags, u16 flags2, s32 type,
-		struct coord *pos, f32 pitch, s16 *rooms, s32 room,
+		struct coord *pos, f32 pitch, RoomNum *rooms, s32 room,
 		f32 dist1, f32 dist2, f32 dist3)
 {
 	union soundnumhack spac;
@@ -1123,12 +1123,12 @@ void psModify(s32 channelnum, s32 volume, s16 padnum, struct prop *prop, s32 vol
 	}
 }
 
-s32 psCalculateVol(struct coord *pos, f32 dist1, f32 dist2, f32 dist3, s16 *rooms, s16 soundnum, s32 arg6, f32 *playerdistptr)
+s32 psCalculateVol(struct coord *pos, f32 dist1, f32 dist2, f32 dist3, RoomNum *rooms, s16 soundnum, s32 arg6, f32 *playerdistptr)
 {
 	union soundnumhack sp6c;
 	union soundnumhack sp68;
 	f32 playerdist;
-	s16 roomnum;
+	RoomNum roomnum;
 	s32 s0;
 	s32 i;
 
@@ -1382,7 +1382,7 @@ s32 psCalculatePan(struct coord *pos, f32 dist1, f32 dist2, f32 dist3, f32 playe
  * If the given soundnum were to play at the given world position, calculate the
  * final volume and pan and write them to the vol and pan pointers.
  */
-void psGetTheoreticalVolPan(struct coord *pos, s16 *rooms, s16 soundnum, s32 *vol, s32 *pan)
+void psGetTheoreticalVolPan(struct coord *pos, RoomNum *rooms, s16 soundnum, s32 *vol, s32 *pan)
 {
 	f32 dist1;
 	f32 dist2;
@@ -1434,7 +1434,7 @@ void psGetTheoreticalVolPan(struct coord *pos, s16 *rooms, s16 soundnum, s32 *vo
 }
 #endif
 
-void psApplyVolPan(struct sndstate *handle, struct coord *pos, f32 dist1, f32 dist2, f32 dist3, s16 *rooms, s16 soundnum, s32 arg7, f32 *distanceptr)
+void psApplyVolPan(struct sndstate *handle, struct coord *pos, f32 dist1, f32 dist2, f32 dist3, RoomNum *rooms, s16 soundnum, s32 arg7, f32 *distanceptr)
 {
 	union soundnumhack sp5c;
 	union soundnumhack sp58;
diff --git a/src/game/room.c b/src/game/room.c
index 51e889ac8..8ee216e86 100644
--- a/src/game/room.c
+++ b/src/game/room.c
@@ -47,8 +47,8 @@
  */
 
 u8 *g_RoomMtxAges;
-s16 *g_RoomMtxLinkedRooms;
-s16 *g_RoomMtxBaseRooms;
+RoomNum *g_RoomMtxLinkedRooms;
+RoomNum *g_RoomMtxBaseRooms;
 f32 *g_RoomMtxScales;
 Mtxf *g_RoomMtxMatrices;
 
diff --git a/src/game/roomreset.c b/src/game/roomreset.c
index dd5ab8c01..d02e12820 100644
--- a/src/game/roomreset.c
+++ b/src/game/roomreset.c
@@ -15,10 +15,10 @@ void roomsReset(void)
 	g_RoomMtxNumSlots = PLAYERCOUNT() >= 2 ? 200 : 120;
 
 	g_RoomMtxAges = mempAlloc(ALIGN16(g_RoomMtxNumSlots), MEMPOOL_STAGE);
-	g_RoomMtxLinkedRooms = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(s16)), MEMPOOL_STAGE);
-	g_RoomMtxBaseRooms = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(s16)), MEMPOOL_STAGE);
-	g_RoomMtxScales = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(f32)), MEMPOOL_STAGE);
-	g_RoomMtxMatrices = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(Mtxf)), MEMPOOL_STAGE);
+	g_RoomMtxLinkedRooms = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(*g_RoomMtxLinkedRooms)), MEMPOOL_STAGE);
+	g_RoomMtxBaseRooms = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(*g_RoomMtxBaseRooms)), MEMPOOL_STAGE);
+	g_RoomMtxScales = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(*g_RoomMtxScales)), MEMPOOL_STAGE);
+	g_RoomMtxMatrices = mempAlloc(ALIGN16(g_RoomMtxNumSlots * sizeof(*g_RoomMtxMatrices)), MEMPOOL_STAGE);
 
 	for (i = 0; i < PLAYERCOUNT(); i++) {
 		g_Vars.players[i]->lastroomforoffset = -1;
diff --git a/src/game/setup.c b/src/game/setup.c
index fd0d5f718..d532db458 100644
--- a/src/game/setup.c
+++ b/src/game/setup.c
@@ -389,7 +389,7 @@ void setupCreateObject(struct defaultobj *obj, s32 cmdindex)
 	struct coord centre;
 	f32 scale;
 	struct coord pos;
-	s16 rooms[8];
+	RoomNum rooms[8];
 	struct prop *prop2;
 	u32 flag40;
 	u32 stack;
@@ -1084,7 +1084,7 @@ void setupCreateDoor(struct doorobj *door, s32 cmdindex)
 		struct prop *prop;
 		s32 siblingcmdindex;
 		struct coord pos;
-		s16 rooms[8];
+		RoomNum rooms[8];
 		Mtxf finalmtx;
 		struct coord centre;
 		Mtxf zrotmtx;
diff --git a/src/game/setupcover.c b/src/game/setupcover.c
index d03a0cb44..7a592b953 100644
--- a/src/game/setupcover.c
+++ b/src/game/setupcover.c
@@ -26,13 +26,13 @@ void setupPrepareCover(void)
 {
 	s32 i;
 	s32 numcovers = g_PadsFile->numcovers;
-	s16 *roomsptr;
+	RoomNum *roomsptr;
 	f32 scale = 1;
 	struct coord aimpos;
 	struct cover cover;
 	u16 specialcovernums[1024];
-	s16 inrooms[21];
-	s16 aboverooms[21];
+	RoomNum inrooms[21];
+	RoomNum aboverooms[21];
 
 	g_CoverFlags = mempAlloc(ALIGN16(numcovers * sizeof(u16)), MEMPOOL_STAGE);
 	g_CoverRooms = mempAlloc(ALIGN16(numcovers * sizeof(s32)), MEMPOOL_STAGE);
@@ -80,7 +80,7 @@ void setupPrepareCover(void)
 					s32 room = cdFindFloorRoomAtPos(cover.pos, roomsptr);
 
 					if (room > 0) {
-						g_CoverRooms[i] = (s16)room;
+						g_CoverRooms[i] = (RoomNum)room;
 					} else {
 						g_CoverRooms[i] = roomsptr[0];
 					}
@@ -106,7 +106,7 @@ void setupPrepareCover(void)
 						s32 aimroom = cdFindFloorRoomAtPos(&aimpos, roomsptr);
 
 						if (aimroom > 0) {
-							g_CoverFlags[i] |= (g_CoverRooms[i] == (s16)aimroom) ? COVERFLAG_AIMSAMEROOM : COVERFLAG_AIMDIFFROOM;
+							g_CoverFlags[i] |= (g_CoverRooms[i] == (RoomNum)aimroom) ? COVERFLAG_AIMSAMEROOM : COVERFLAG_AIMDIFFROOM;
 						} else {
 							g_CoverFlags[i] |= (g_CoverRooms[i] == roomsptr[0]) ? COVERFLAG_AIMSAMEROOM : COVERFLAG_AIMDIFFROOM;
 						}
diff --git a/src/game/setuppads.c b/src/game/setuppads.c
index d4f4a9a8f..9e629fdad 100644
--- a/src/game/setuppads.c
+++ b/src/game/setuppads.c
@@ -28,15 +28,15 @@
 void setupPreparePads(void)
 {
 	struct packedpad *packedpad;
-	s16 *roomsptr;
+	RoomNum *roomsptr;
 	s32 padnum;
 	s32 numpads;
 	s32 roomnum;
 	struct pad pad;
 	struct waypoint *waypoint;
 	struct waygroup *waygroup;
-	s16 inrooms[24];
-	s16 aboverooms[22];
+	RoomNum inrooms[24];
+	RoomNum aboverooms[22];
 	s32 offset;
 
 	g_PadsFile = (struct padsfileheader *)g_StageSetup.padfiledata;
diff --git a/src/game/setuputils.c b/src/game/setuputils.c
index 8f1288899..b62fc2d64 100644
--- a/src/game/setuputils.c
+++ b/src/game/setuputils.c
@@ -186,7 +186,7 @@ bool setup0f092304(struct defaultobj *obj, struct coord *arg1, struct coord *arg
 	return setupGetObjBbox(obj, &obj->prop->pos, obj->realrot, arg1, arg2);
 }
 
-void setup0f09233c(struct defaultobj *obj, struct coord *pos, f32 realrot[3][3], s16 *rooms)
+void setup0f09233c(struct defaultobj *obj, struct coord *pos, f32 realrot[3][3], RoomNum *rooms)
 {
 	struct coord a;
 	struct coord b;
diff --git a/src/game/shards.c b/src/game/shards.c
index b3235a352..8291ac7a4 100644
--- a/src/game/shards.c
+++ b/src/game/shards.c
@@ -19,7 +19,7 @@ struct shard *g_Shards;
 s32 g_NextShardNum = 0;
 bool g_ShardsActive = false;
 
-void shardCreate(s16 room, struct coord *pos, f32 rotx, f32 size, s32 type);
+void shardCreate(RoomNum room, struct coord *pos, f32 rotx, f32 size, s32 type);
 
 void shardsCreate(struct coord *pos, f32 *rotx, f32 *roty, f32 *rotz, f32 relxmin, f32 relxmax, f32 relymin, f32 relymax, s32 type, struct prop *prop)
 {
@@ -111,7 +111,7 @@ void shardsCreate(struct coord *pos, f32 *rotx, f32 *roty, f32 *rotz, f32 relxmi
 	}
 }
 
-void shardCreate(s16 room, struct coord *pos, f32 rotx, f32 size, s32 type)
+void shardCreate(RoomNum room, struct coord *pos, f32 rotx, f32 size, s32 type)
 {
 	f32 velx = RANDOMFRAC() * 2.0f - 1.0f;
 	f32 vely = RANDOMFRAC() * 1.12f - 0.12f;
@@ -211,7 +211,7 @@ void shardCreate(s16 room, struct coord *pos, f32 rotx, f32 size, s32 type)
 Gfx *shardsRenderWood(Gfx *gdl)
 {
 	if (g_ShardsActive) {
-		s16 prevroom = 0;
+		RoomNum prevroom = 0;
 		s32 i;
 		Mtxf shardmtx;
 		s32 j;
@@ -325,7 +325,7 @@ Gfx *shardsRenderWood(Gfx *gdl)
 Gfx *shardsRenderGlass(Gfx *gdl)
 {
 	if (g_ShardsActive) {
-		s16 prevroom = 0;
+		RoomNum prevroom = 0;
 		s32 i;
 		Mtxf shardmtx;
 		s32 j;
diff --git a/src/game/smoke.c b/src/game/smoke.c
index af2439db1..edc7d5e37 100644
--- a/src/game/smoke.c
+++ b/src/game/smoke.c
@@ -261,7 +261,7 @@ Gfx *smokeRenderPart(struct smoke *smoke, struct smokepart *part, Gfx *gdl, stru
 	return gdl;
 }
 
-struct smoke *smokeCreate(struct coord *pos, s16 *rooms, s16 type)
+struct smoke *smokeCreate(struct coord *pos, RoomNum *rooms, s16 type)
 {
 	struct smoke *smoke = NULL;
 	s32 playercount = PLAYERCOUNT();
@@ -326,7 +326,7 @@ struct smoke *smokeCreate(struct coord *pos, s16 *rooms, s16 type)
 	return smoke;
 }
 
-bool smokeCreateForHand(struct coord *pos, s16 *rooms, s16 type, s32 handnum)
+bool smokeCreateForHand(struct coord *pos, RoomNum *rooms, s16 type, s32 handnum)
 {
 	struct smoke *smoke;
 	s32 i;
@@ -368,7 +368,7 @@ bool smokeCreateForHand(struct coord *pos, s16 *rooms, s16 type, s32 handnum)
  * smoke parts have a size of zero. Perhaps the caller is supposed to check if
  * this function returns false and reuse the zero-sized smoke parts if so?
  */
-bool smokeCreateWithSource(void *source, struct coord *pos, s16 *rooms, s16 type, bool srcispadeffect)
+bool smokeCreateWithSource(void *source, struct coord *pos, RoomNum *rooms, s16 type, bool srcispadeffect)
 {
 	struct smoke *smoke;
 	s32 i;
@@ -415,7 +415,7 @@ void smokeCreateAtProp(struct prop *prop, s16 type)
 	smokeCreateWithSource(prop, &prop->pos, prop->rooms, type, false);
 }
 
-void smokeCreateAtPadEffect(struct padeffectobj *effect, struct coord *pos, s16 *rooms, s16 type)
+void smokeCreateAtPadEffect(struct padeffectobj *effect, struct coord *pos, RoomNum *rooms, s16 type)
 {
 	smokeCreateWithSource(effect, pos, rooms, type, true);
 }
@@ -432,7 +432,7 @@ void smokeClearForProp(struct prop *prop)
 	}
 }
 
-struct smoke *smokeCreateSimple(struct coord *pos, s16 *rooms, s16 type)
+struct smoke *smokeCreateSimple(struct coord *pos, RoomNum *rooms, s16 type)
 {
 	return smokeCreate(pos, rooms, type);
 }
diff --git a/src/game/splat.c b/src/game/splat.c
index 41e41146e..15079869a 100644
--- a/src/game/splat.c
+++ b/src/game/splat.c
@@ -245,9 +245,9 @@ bool splat0f149274(f32 arg0, struct prop *chrprop, struct shotdata *shotdata, f3
 	struct prop *objprop;
 	struct hitthing hitthing;
 	struct hitthing besthitthing;
-	s16 rooms[32];
-	s16 gunrooms[8];
-	s16 endrooms[8];
+	RoomNum rooms[32];
+	RoomNum gunrooms[8];
+	RoomNum endrooms[8];
 	struct coord endpos;
 	s32 i;
 	struct coord *sp50c;
@@ -422,7 +422,7 @@ void splat0f14986c(struct splatdata *splat)
 	bool sp84 = splat->isskedar & 1;
 	bool translucent = splat->translucent;
 	f32 distance;
-	s16 smokerooms[2];
+	RoomNum smokerooms[2];
 
 	texnum = WALLHITTEX_BLOOD1 + (random() % 3);
 
diff --git a/src/game/training.c b/src/game/training.c
index edfc1feed..157ff84fb 100644
--- a/src/game/training.c
+++ b/src/game/training.c
@@ -1248,9 +1248,9 @@ void frEndSession(bool hidetargets)
 	s32 j;
 	s16 propnums[256];
 	s16 *propnumptr;
-	s16 rooms[20];
+	RoomNum rooms[20];
 	u32 stack1;
-	s16 rooms2[10];
+	RoomNum rooms2[10];
 	u32 stack2;
 
 	if (g_FrDataLoaded) {
@@ -1507,8 +1507,8 @@ bool frIsAmmoWasted(void)
 	s32 ammototal[2];
 	s16 *propnumptr;
 	s16 propnums[258];
-	s16 rooms20[22];
-	s16 rooms10[12];
+	RoomNum rooms20[22];
+	RoomNum rooms10[12];
 	u32 stack[4];
 	s32 ammotype;
 	struct hand *hand;
@@ -3144,7 +3144,7 @@ void htEnd(void)
 	struct prop *prop;
 	s16 *propnum;
 	s16 propnums[256];
-	s16 rooms[5] = { 0x0016, 0x0017, 0x0018, 0x0019, -1 };
+	RoomNum rooms[5] = { 0x0016, 0x0017, 0x0018, 0x0019, -1 };
 	struct waypoint *waypoints = g_StageSetup.waypoints;
 
 	g_HtData.intraining = false;
diff --git a/src/game/wallhit.c b/src/game/wallhit.c
index c5e244369..393dbb1b1 100644
--- a/src/game/wallhit.c
+++ b/src/game/wallhit.c
@@ -633,7 +633,7 @@ const char var7f1b5c44[] = "";
 const char var7f1b5c48[] = "";
 
 void wallhitCreate(struct coord *relpos, struct coord *arg1, struct coord *arg2, s16 arg3[3],
-		s16 arg4[3], s16 texnum, s16 room, struct prop *objprop,
+		s16 arg4[3], s16 texnum, RoomNum room, struct prop *objprop,
 		s8 mtxindex, s8 arg9, struct chrdata *chr, bool xlu)
 {
 	f32 scale = RANDOMFRAC() * 0.1f + 0.6f;
@@ -648,7 +648,7 @@ void wallhitCreate(struct coord *relpos, struct coord *arg1, struct coord *arg2,
 }
 
 void wallhitCreateWith20Args(struct coord *relpos, struct coord *arg1, struct coord *arg2, s16 arg3[3],
-		s16 arg4[3], s16 texnum, s16 room, struct prop *objprop,
+		s16 arg4[3], s16 texnum, RoomNum room, struct prop *objprop,
 		struct prop *chrprop, s8 mtxindex, s8 arg10, struct chrdata *chr,
 		f32 width, f32 height, u8 minalpha, u8 maxalpha,
 		s32 rotdeg, u32 timermax, u32 timerspeed, bool xlu)
diff --git a/src/game/weather.c b/src/game/weather.c
index 236c7cc6a..f09a44988 100644
--- a/src/game/weather.c
+++ b/src/game/weather.c
@@ -856,7 +856,7 @@ Gfx *weatherRenderRain(Gfx *gdl, struct weatherdata *weather, s32 arg2)
 		u32 stack2;
 		struct coord distcamtobbmax;
 		struct coord distcamtobbmin;
-		s16 neighbours[20];
+		RoomNum neighbours[20];
 
 		particledata = weather->particledata[arg2];
 		numtris = 0;
@@ -2872,7 +2872,7 @@ Gfx *weatherRenderSnow(Gfx *gdl, struct weatherdata *weather, s32 arg2)
 	s32 i; // 184
 	struct coord sp178;
 	struct coord sp16c;
-	s16 sp144[20];
+	RoomNum sp144[20];
 	struct coord sp124;
 	struct coord sp118;
 	f32 f26;
diff --git a/src/include/bss.h b/src/include/bss.h
index 1791c1c93..67eb234e9 100644
--- a/src/include/bss.h
+++ b/src/include/bss.h
@@ -232,8 +232,8 @@ extern bool g_FogEnabled;
 extern bool g_EnvHasTransparency;
 extern struct distfadesettings *g_EnvDistFadeSettingsPtr;
 extern u8 *g_RoomMtxAges;
-extern s16 *g_RoomMtxLinkedRooms;
-extern s16 *g_RoomMtxBaseRooms;
+extern RoomNum *g_RoomMtxLinkedRooms;
+extern RoomNum *g_RoomMtxBaseRooms;
 extern f32 *g_RoomMtxScales;
 extern Mtxf *g_RoomMtxMatrices;
 extern struct fileinfo g_FileInfo[NUM_FILES];
diff --git a/src/include/game/bg.h b/src/include/game/bg.h
index cb3cd068d..0ac8645ca 100644
--- a/src/include/game/bg.h
+++ b/src/include/game/bg.h
@@ -72,25 +72,25 @@ bool bgTestHitInVtxBatch(struct coord *arg0, struct coord *arg1, struct coord *a
 s32 bg0f1612e4(struct coord *bbmin, struct coord *bbmax, struct coord *frompos, struct coord *dist, struct coord *arg4, struct coord *arg5);
 bool bgTestHitInRoom(struct coord *frompos, struct coord *topos, s32 roomnum, struct hitthing *hitthing);
 bool bgRoomIsLoaded(s32 room);
-bool bgRoomContainsCoord(struct coord *pos, s16 roomnum);
-bool bgTestPosInRoomCheap(struct coord *pos, s16 roomnum);
-bool bgTestPosInRoomExpensive(struct coord *pos, s16 roomnum);
-bool bgTestPosInRoom(struct coord *pos, s16 roomnum);
-void bgFindRoomsByPos(struct coord *pos, s16 *inrooms, s16 *aboverooms, s32 max, s16 *bestroom);
+bool bgRoomContainsCoord(struct coord *pos, RoomNum roomnum);
+bool bgTestPosInRoomCheap(struct coord *pos, RoomNum roomnum);
+bool bgTestPosInRoomExpensive(struct coord *pos, RoomNum roomnum);
+bool bgTestPosInRoom(struct coord *pos, RoomNum roomnum);
+void bgFindRoomsByPos(struct coord *pos, RoomNum *inrooms, RoomNum *aboverooms, s32 max, RoomNum *bestroom);
 bool bgCmdPushValue(bool value);
 bool bgCmdPopValue(void);
 bool bgCmdGetNthValueFromEnd(s32 offset);
 struct bgcmd *bgCmdExecuteBranch(struct bgcmd *cmd, bool s2);
 struct bgcmd *bgCmdExecute(struct bgcmd *cmd);
 void bgTickPortalsXray(void);
-void bgAddToSnake(s16 fromroomnum, s16 roomnum, s16 draworder, struct screenbox *box);
+void bgAddToSnake(RoomNum fromroomnum, RoomNum roomnum, s16 draworder, struct screenbox *box);
 void bgConsumeSnakeItem(struct bgsnakeitem *arg0);
 bool bgTryConsumeSnake(void);
 void bgChooseRoomsToLoad(void);
 void bgTickPortals(void);
 Gfx *bgRenderSceneAndLoadCandidate(Gfx *gdl);
-s32 bgGetForceOnscreenRooms(s16 *rooms, s32 len);
-s32 bgRoomGetNeighbours(s32 room, s16 *rooms, s32 len);
+s32 bgGetForceOnscreenRooms(RoomNum *rooms, s32 len);
+s32 bgRoomGetNeighbours(s32 room, RoomNum *rooms, s32 len);
 bool bgRoomsAreNeighbours(s32 roomnum1, s32 roomnum2);
 void bgCalculateScreenProperties(void);
 void bgExpandRoomToPortals(s32 roomnum);
@@ -101,6 +101,6 @@ void bgSetPortalOpenState(s32 portal, bool open);
 s32 bgFindPortalBetweenPositions(struct coord *pos1, struct coord *pos2);
 bool bgIsBboxOverlapping(struct coord *arg0, struct coord *arg1, struct coord *arg2, struct coord *arg3);
 void bgCalculatePortalBbox(s32 portalnum, struct coord *bbmin, struct coord *bbmax);
-void bgFindEnteredRooms(struct coord *bbmin, struct coord *upper, s16 *rooms, s32 maxlen, bool arg4);
+void bgFindEnteredRooms(struct coord *bbmin, struct coord *upper, RoomNum *rooms, s32 maxlen, bool arg4);
 
 #endif
diff --git a/src/include/game/body.h b/src/include/game/body.h
index e913574ef..4cc36931c 100644
--- a/src/include/game/body.h
+++ b/src/include/game/body.h
@@ -16,7 +16,7 @@ struct model *bodyAllocateModel(s32 bodynum, s32 headnum, u32 spawnflags);
 s32 body0f02d3f8(void);
 s32 bodyChooseHead(s32 bodynum);
 void bodyAllocateChr(s32 stagenum, struct packedchr *packed, s32 cmdindex);
-struct prop *bodyAllocateEyespy(struct pad *pad, s16 room);
+struct prop *bodyAllocateEyespy(struct pad *pad, RoomNum room);
 void bodyCalculateHeadOffset(struct modeldef *headmodeldef, s32 headnum, s32 bodynum);
 
 #endif
diff --git a/src/include/game/bondeyespy.h b/src/include/game/bondeyespy.h
index f3af79691..033893c17 100644
--- a/src/include/game/bondeyespy.h
+++ b/src/include/game/bondeyespy.h
@@ -4,7 +4,7 @@
 #include "data.h"
 #include "types.h"
 
-f32 eyespyFindGround(s16 *floorroom);
+f32 eyespyFindGround(RoomNum *floorroom);
 s32 eyespyTryMoveUpwards(f32 yvel);
 s32 eyespyCalculateNewPosition(struct coord *vel);
 bool eyespyCalculateNewPositionWithPush(struct coord *vel);
diff --git a/src/include/game/bondgun.h b/src/include/game/bondgun.h
index 1e753a449..e704cdcad 100644
--- a/src/include/game/bondgun.h
+++ b/src/include/game/bondgun.h
@@ -73,9 +73,9 @@ void bgunTickMasterLoad(void);
 void bgunTickLoad(void);
 bool bgunLoadAll(void);
 struct modeldef *bgunGetCartModeldef(void);
-void bgun0f09ebcc(struct defaultobj *obj, struct coord *coord, s16 *rooms, Mtxf *matrix1, struct coord *velocity, Mtxf *matrix2, struct prop *prop, struct coord *pos);
+void bgun0f09ebcc(struct defaultobj *obj, struct coord *coord, RoomNum *rooms, Mtxf *matrix1, struct coord *velocity, Mtxf *matrix2, struct prop *prop, struct coord *pos);
 void bgun0f09ed2c(struct defaultobj *obj, struct coord *coord, Mtxf *arg2, struct coord *velocity, Mtxf *arg4);
-struct defaultobj *bgunCreateThrownProjectile2(struct chrdata *chr, struct gset *gset, struct coord *pos, s16 *rooms, Mtxf *arg4, struct coord *velocity);
+struct defaultobj *bgunCreateThrownProjectile2(struct chrdata *chr, struct gset *gset, struct coord *pos, RoomNum *rooms, Mtxf *arg4, struct coord *velocity);
 void bgunCreateThrownProjectile(s32 handnum, struct gset *gset);
 void bgunUpdateHeldRocket(s32 handnum);
 void bgunCreateHeldRocket(s32 handnum, struct weaponfunc_shootprojectile *func);
@@ -142,8 +142,8 @@ s32 bgunAllocateFireslot(void);
 void bgunRender(Gfx **gdl);
 struct sndstate **bgunAllocateAudioHandle(void);
 void bgunPlayPropHitSound(struct gset *gset, struct prop *prop, s32 texturenum);
-void bgunPlayGlassHitSound(struct coord *pos, s16 *rooms, s32 texturenum);
-void bgunPlayBgHitSound(struct gset *gset, struct coord *hitpos, s32 texturenum, s16 *rooms);
+void bgunPlayGlassHitSound(struct coord *pos, RoomNum *rooms, s32 texturenum);
+void bgunPlayBgHitSound(struct gset *gset, struct coord *hitpos, s32 texturenum, RoomNum *rooms);
 void bgunSetTriggerOn(s32 handnum, bool on);
 s32 bgunConsiderToggleGunFunction(s32 usedowntime, bool trigpressed, bool fromactivemenu);
 void bgun0f0a8c50(void);
diff --git a/src/include/game/bondmove.h b/src/include/game/bondmove.h
index 378ab167c..7733b613f 100644
--- a/src/include/game/bondmove.h
+++ b/src/include/game/bondmove.h
@@ -30,8 +30,8 @@ void bmoveUpdateSpeedThetaControl(f32 value);
 f32 bmoveCalculateLookahead(void);
 void bmoveResetMoveData(struct movedata *data);
 void bmoveProcessInput(bool allowc1x, bool allowc1y, bool allowc1buttons, bool ignorec2);
-void bmoveFindEnteredRoomsByPos(struct player *player, struct coord *arg1, s16 *rooms);
-void bmoveFindEnteredRooms(struct player *player, s16 *rooms);
+void bmoveFindEnteredRoomsByPos(struct player *player, struct coord *arg1, RoomNum *rooms);
+void bmoveFindEnteredRooms(struct player *player, RoomNum *rooms);
 void bmoveUpdateRooms(struct player *player);
 void bmove0f0cb904(struct coord *coord);
 void bmove0f0cba88(f32 *a, f32 *b, struct coord *c, f32 mult1, f32 mult2);
diff --git a/src/include/game/bot.h b/src/include/game/bot.h
index 4e188c48e..729822a04 100644
--- a/src/include/game/bot.h
+++ b/src/include/game/bot.h
@@ -4,7 +4,7 @@
 #include "data.h"
 #include "types.h"
 
-bool botroomFindPos(s16 room, struct coord *pos, f32 *angleptr, s32 *padnumptr, s32 *covernumptr);
+bool botroomFindPos(RoomNum room, struct coord *pos, f32 *angleptr, s32 *padnumptr, s32 *covernumptr);
 
 bool botIsDizzy(struct chrdata *chr);
 void botReset(struct chrdata *chr, u8 respawning);
@@ -45,8 +45,8 @@ char *botGetCommandName(s32 command);
 void botApplyAttack(struct chrdata *chr, struct prop *prop);
 void botApplyFollow(struct chrdata *chr, struct prop *prop);
 void botApplyProtect(struct chrdata *chr, struct prop *prop);
-void botApplyDefend(struct chrdata *chr, struct coord *pos, s16 *room, f32 angle);
-void botApplyHold(struct chrdata *chr, struct coord *pos, s16 *room, f32 angle);
+void botApplyDefend(struct chrdata *chr, struct coord *pos, RoomNum *room, f32 angle);
+void botApplyHold(struct chrdata *chr, struct coord *pos, RoomNum *room, f32 angle);
 void botApplyScenarioCommand(struct chrdata *chr, u32 arg1);
 bool botCanFollow(struct chrdata *leader, struct chrdata *follower);
 s32 botFindTeammateToFollow(struct chrdata *chr, f32 range);
diff --git a/src/include/game/botact.h b/src/include/game/botact.h
index 801b20c6d..4b91ac0d4 100644
--- a/src/include/game/botact.h
+++ b/src/include/game/botact.h
@@ -18,7 +18,7 @@ u32 botactGetProjectileThrowInterval(u32 weapon);
 s32 botactGetWeaponByAmmoType(s32 ammotype);
 void botactThrow(struct chrdata *chr);
 s32 botactGetShootInterval60(s32 weaponnum, s32 funcnum);
-bool botactFindRocketRoute(struct chrdata *chr, struct coord *frompos, struct coord *topos, s16 *fromrooms, s16 *torooms, struct projectile *projectile);
+bool botactFindRocketRoute(struct chrdata *chr, struct coord *frompos, struct coord *topos, RoomNum *fromrooms, RoomNum *torooms, struct projectile *projectile);
 void botactGetRocketNextStepPos(u16 padnum, struct coord *pos);
 void botactCreateSlayerRocket(struct chrdata *chr);
 
diff --git a/src/include/game/camera.h b/src/include/game/camera.h
index 725ea06c8..f8dd37acf 100644
--- a/src/include/game/camera.h
+++ b/src/include/game/camera.h
@@ -43,6 +43,6 @@ f32 camGetPerspAspect(void);
 void cam0f0b5838(void);
 bool cam0f0b5b9c(struct coord *arg0, f32 arg1);
 bool camIsPosInScreenBox(struct coord *pos, f32 arg1, struct drawslot *drawslot);
-bool camIsPosInFovAndVisibleRoom(s16 *rooms, struct coord *pos, f32 arg2);
+bool camIsPosInFovAndVisibleRoom(RoomNum *rooms, struct coord *pos, f32 arg2);
 
 #endif
diff --git a/src/include/game/chr.h b/src/include/game/chr.h
index 41b7654cd..151da2705 100644
--- a/src/include/game/chr.h
+++ b/src/include/game/chr.h
@@ -6,24 +6,24 @@
 
 void chrSetChrnum(struct chrdata *chr, s16 chrnum);
 void chrDeregister(s32 chrnum);
-void chrCalculatePushPos(struct chrdata *chr, struct coord *pos, s16 *rooms, bool arg3);
+void chrCalculatePushPos(struct chrdata *chr, struct coord *pos, RoomNum *rooms, bool arg3);
 
 #if VERSION >= VERSION_NTSC_1_0
-bool chr0f01f264(struct chrdata *chr, struct coord *pos, s16 *rooms, f32 arg3, bool arg4);
+bool chr0f01f264(struct chrdata *chr, struct coord *pos, RoomNum *rooms, f32 arg3, bool arg4);
 #else
-bool chr0f01f264(struct chrdata *chr, struct coord *pos, s16 *rooms, f32 arg3);
+bool chr0f01f264(struct chrdata *chr, struct coord *pos, RoomNum *rooms, f32 arg3);
 #endif
 
 bool chr0f01f378(struct model *model, struct coord *arg1, struct coord *arg2, f32 *mangroundptr);
 s32 chrsGetNumFree(void);
 s16 chrsGetNextUnusedChrnum(void);
-struct prop *chr0f020b14(struct prop *prop, struct model *model, struct coord *pos, s16 *rooms, f32 arg3, u8 *ailist);
+struct prop *chr0f020b14(struct prop *prop, struct model *model, struct coord *pos, RoomNum *rooms, f32 arg3, u8 *ailist);
 void chrRemove(struct prop *prop, bool free);
 void chrUpdateAimProperties(struct chrdata *chr);
 void chrFlinchBody(struct chrdata *chr);
 void chrFlinchHead(struct chrdata *chr, f32 arg1);
 f32 chrGetFlinchAmount(struct chrdata *chr);
-void chr0f021fa8(struct chrdata *chr, struct coord *pos, s16 *rooms);
+void chr0f021fa8(struct chrdata *chr, struct coord *pos, RoomNum *rooms);
 void chr0f0220ec(struct chrdata *chr, s32 lvupdate240, bool arg2);
 void chr0f022214(struct chrdata *chr, struct prop *child, bool fulltick);
 void chrUpdateCloak(struct chrdata *chr);
@@ -80,9 +80,9 @@ f32 chrGetMaxDamage(struct chrdata *chr);
 void chrAddHealth(struct chrdata *chr, f32 health);
 f32 chrGetArmor(struct chrdata *chr);
 void chrInit(struct prop *prop, u8 *ailist);
-struct prop *chrAllocate(struct model *model, struct coord *pos, s16 *rooms, f32 faceangle, u8 *ailist);
+struct prop *chrAllocate(struct model *model, struct coord *pos, RoomNum *rooms, f32 faceangle, u8 *ailist);
 void chrClearReferences(s32 propnum);
-void chr0f022084(struct chrdata *chr, s16 *room);
+void chr0f022084(struct chrdata *chr, RoomNum *room);
 void chr0f0220ac(struct chrdata *chr);
 void chrCloak(struct chrdata *chr, bool arg1);
 void chrUncloak(struct chrdata *chr, bool value);
diff --git a/src/include/game/chraction.h b/src/include/game/chraction.h
index 982103e05..e981d0369 100644
--- a/src/include/game/chraction.h
+++ b/src/include/game/chraction.h
@@ -66,8 +66,8 @@ void chrDamageByImpact(struct chrdata *chr, f32 damage, struct coord *vector, st
 void chrDamageByExplosion(struct chrdata *chr, f32 damage, struct coord *vector, struct prop *prop, struct coord *explosionpos);
 void playerUpdateDamageStats(struct prop *attacker, struct prop *victim, f32 damage);
 void chrDamage(struct chrdata *chr, f32 damage, struct coord *vector, struct gset *gset, struct prop *aprop, s32 hitpart, bool damageshield, struct prop *prop2, struct modelnode *node, struct model *model, s32 side, s16 *arg11, bool explosion, struct coord *explosionpos);
-bool func0f03645c(struct chrdata *chr, struct coord *arg1, s16 *arg2, struct coord *arg3, struct coord *arg4, s32 cdtypes);
-bool func0f03654c(struct chrdata *chr, struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2, struct coord *vector, f32 arg6, u32 types);
+bool func0f03645c(struct chrdata *chr, struct coord *arg1, RoomNum *arg2, struct coord *arg3, struct coord *arg4, s32 cdtypes);
+bool func0f03654c(struct chrdata *chr, struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2, struct coord *vector, f32 arg6, u32 types);
 bool propchrHasClearLineToPos(struct prop *prop, struct coord *dstpos, struct coord *vector);
 bool propchrHasClearLineInVector(struct prop *prop, struct coord *coord, f32 arg2);
 bool func0f036974(struct prop *prop, struct coord *coord);
@@ -75,9 +75,9 @@ void chrGetSideVectorToTarget(struct chrdata *chr, bool side, struct coord *vect
 bool chrCanRollInDirection(struct chrdata *chr, bool toleft, f32 distance);
 void chrGetSideVector(struct chrdata *chr, bool side, struct coord *vector);
 bool chrCanJumpInDirection(struct chrdata *chr, bool side, f32 distance);
-bool chrIsRoomOffScreen(struct chrdata *chr, struct coord *waypos, s16 *wayrooms);
+bool chrIsRoomOffScreen(struct chrdata *chr, struct coord *waypos, RoomNum *wayrooms);
 void chrGoPosInitMagic(struct chrdata *chr, struct waydata *waydata, struct coord *arg2, struct coord *prevpos);
-void chrGoPosGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, s16 *rooms, u32 *flags);
+void chrGoPosGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, RoomNum *rooms, u32 *flags);
 f32 func0f0370a8(struct chrdata *chr);
 s32 chrGoPosCalculateBaseTtl(struct chrdata *chr);
 void chrGoPosConsiderRestart(struct chrdata *chr);
@@ -85,20 +85,20 @@ void chrGoPosInitExpensive(struct chrdata *chr);
 void chrGoPosAdvanceWaypoint(struct chrdata *chr);
 s32 chrPatrolCalculateStep(struct chrdata *chr, bool *forward, s32 numsteps);
 s16 chrPatrolCalculatePadNum(struct chrdata *chr, s32 numsteps);
-void chrPatrolGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, s16 *rooms, u32 *flags);
+void chrPatrolGetCurWaypointInfoWithFlags(struct chrdata *chr, struct coord *pos, RoomNum *rooms, u32 *flags);
 void func0f037580(struct chrdata *chr);
 void func0f0375b0(struct chrdata *chr);
-void chrNavTickMagic(struct chrdata *chr, struct waydata *waydata, f32 speed, struct coord *arg3, s16 *rooms);
+void chrNavTickMagic(struct chrdata *chr, struct waydata *waydata, f32 speed, struct coord *arg3, RoomNum *rooms);
 void chrCalculatePosition(struct chrdata *chr, struct coord *pos);
 void chrGoPosChooseAnimation(struct chrdata *chr);
-bool chrGoToRoomPos(struct chrdata *chr, struct coord *pos, s16 *rooms, u32 goposflags);
+bool chrGoToRoomPos(struct chrdata *chr, struct coord *pos, RoomNum *rooms, u32 goposflags);
 void chrPatrolChooseAnimation(struct chrdata *chr);
 void chrStartPatrol(struct chrdata *chr, struct path *path);
-bool chrHasLosToEntity(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms, bool allowextraheight, u32 attackflags, u32 entityid);
-bool chrHasLosToAttackTarget(struct chrdata *chr, struct coord *pos, s16 *rooms, bool allowextraheight);
-bool chrHasLosToChr(struct chrdata *chr, struct chrdata *target, s16 *room);
-bool chrHasLosToPos(struct chrdata *viewerchr, struct coord *pos, s16 *rooms);
-bool chrHasLosToPosWasteful(struct chrdata *chr, struct coord *pos, s16 *room);
+bool chrHasLosToEntity(struct chrdata *chr, struct coord *chrpos, RoomNum *chrrooms, bool allowextraheight, u32 attackflags, u32 entityid);
+bool chrHasLosToAttackTarget(struct chrdata *chr, struct coord *pos, RoomNum *rooms, bool allowextraheight);
+bool chrHasLosToChr(struct chrdata *chr, struct chrdata *target, RoomNum *room);
+bool chrHasLosToPos(struct chrdata *viewerchr, struct coord *pos, RoomNum *rooms);
+bool chrHasLosToPosWasteful(struct chrdata *chr, struct coord *pos, RoomNum *room);
 bool chrHasLosToProp(struct chrdata *chr, struct prop *prop);
 bool chrIsStopped(struct chrdata *chr);
 bool chrCheckCanSeeTarget(struct chrdata *chr);
@@ -166,8 +166,8 @@ bool posIsArrivingLaterallyAtPos(struct coord *prevpos, struct coord *curpos, st
 bool posIsArrivingAtPos(struct coord *prevpos, struct coord *curpos, struct coord *targetpos, f32 range);
 void chrTickRunPos(struct chrdata *chr);
 void func0f044b68(struct coord *arg0, struct coord *arg1, struct coord *arg2);
-bool chrNavCanSeeNextPos(struct chrdata *chr, struct coord *pos, s16 *rooms, struct coord *aimpos, struct coord *arg4, struct coord *arg5, f32 negchrradius, f32 chrradius, s32 cdtypes, s32 arg9);
-bool chrNavCheckForObstacle(struct chrdata *chr, struct coord *chrpos, s16 *chrrooms, struct coord *aimpos, struct coord *leftpos, struct coord *rightpos, f32 negchrradius, f32 chrradius, s32 cdtypes, bool hasobstacle);
+bool chrNavCanSeeNextPos(struct chrdata *chr, struct coord *pos, RoomNum *rooms, struct coord *aimpos, struct coord *arg4, struct coord *arg5, f32 negchrradius, f32 chrradius, s32 cdtypes, s32 arg9);
+bool chrNavCheckForObstacle(struct chrdata *chr, struct coord *chrpos, RoomNum *chrrooms, struct coord *aimpos, struct coord *leftpos, struct coord *rightpos, f32 negchrradius, f32 chrradius, s32 cdtypes, bool hasobstacle);
 bool chrNavTryObstacle(struct chrdata *chr, struct coord *arg1, bool arg2, struct coord *arg3, f32 radius, bool arg5, struct coord *nextpos, struct waydata *waydata, f32 arg8, s32 cdtypes, s32 arg10);
 struct prop *chrOpenDoor(struct chrdata *chr, struct coord *rangepos);
 void chrNavTickMain(struct chrdata *chr, struct coord *pos, struct waydata *waydata, bool arg3);
@@ -181,7 +181,7 @@ void chraTick(struct chrdata *chr);
 void cutsceneStart(u32 ailistid);
 void chraTickBg(void);
 f32 chrGetAngleToPos(struct chrdata *chr, struct coord *pos);
-void chrGetAttackEntityPos(struct chrdata *chr, u32 attackflags, s32 entityid, struct coord *pos, s16 *rooms);
+void chrGetAttackEntityPos(struct chrdata *chr, u32 attackflags, s32 entityid, struct coord *pos, RoomNum *rooms);
 f32 chrGetAngleFromTargetsFov(struct chrdata *chr);
 f32 chrGetVerticalAngleToTarget(struct chrdata *chr);
 bool chrIsInTargetsFovX(struct chrdata *chr, u8 fov360);
@@ -197,23 +197,23 @@ bool chrIsTargetAimingAtMe(struct chrdata *chr);
 bool chrSawInjury(struct chrdata *chr, u8 arg1);
 bool chrSawDeath(struct chrdata *chr, u8 arg1);
 bool waypointIsWithin90DegreesOfPosAngle(struct waypoint *waypoint, struct coord *pos, f32 angle);
-s32 chrFindWaypointWithinPosQuadrant(struct coord *pos, s16 *rooms, f32 angle, u8 quadrant);
+s32 chrFindWaypointWithinPosQuadrant(struct coord *pos, RoomNum *rooms, f32 angle, u8 quadrant);
 bool func0f04a4ec(struct chrdata *chr, u8 quadrant);
 bool chrSetPadPresetToWaypointWithinTargetQuadrant(struct chrdata *chr, u8 arg1);
 bool chrSetChrPresetToChrNearPad(u32 checktype, struct chrdata *chr, f32 distance, s32 padnum);
-bool chrSetChrPresetToChrNearPos(u8 checktype, struct chrdata *chr, f32 distance, struct coord *pos, s16 *room);
+bool chrSetChrPresetToChrNearPos(u8 checktype, struct chrdata *chr, f32 distance, struct coord *pos, RoomNum *room);
 bool chrSetPadPresetToPadOnRouteToTarget(struct chrdata *chr);
-bool chrIsPosOffScreen(struct coord *pos, s16 *rooms);
+bool chrIsPosOffScreen(struct coord *pos, RoomNum *rooms);
 
 #if VERSION >= VERSION_NTSC_1_0
-bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, s16 *rooms, f32 angle, bool allowonscreen, bool force, bool onlysurrounding);
+bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, RoomNum *rooms, f32 angle, bool allowonscreen, bool force, bool onlysurrounding);
 #else
-bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, s16 *rooms, f32 angle, bool allowonscreen, bool force);
+bool chrAdjustPosForSpawn(f32 chrradius, struct coord *pos, RoomNum *rooms, f32 angle, bool allowonscreen, bool force);
 #endif
 
-struct prop *chrSpawnAtCoord(s32 body, s32 head, struct coord *pos, s16 *room, f32 angle, u8 *ailist, u32 spawnflags);
+struct prop *chrSpawnAtCoord(s32 body, s32 head, struct coord *pos, RoomNum *room, f32 angle, u8 *ailist, u32 spawnflags);
 bool chrIsPropPresetBlockingSightToTarget(struct chrdata *chr);
-bool chrMoveToPos(struct chrdata *chr, struct coord *pos, s16 *room, f32 angle, bool ignorebg);
+bool chrMoveToPos(struct chrdata *chr, struct coord *pos, RoomNum *room, f32 angle, bool ignorebg);
 bool chrCheckCoverOutOfSight(struct chrdata *chr, s32 covernum, bool soft);
 s32 chrAssignCoverByCriteria(struct chrdata *chr, u16 arg1, s32 arg2);
 s32 chrAssignCoverAwayFromDanger(struct chrdata *chr, s32 mindist, s32 maxdist);
@@ -238,9 +238,9 @@ void chrRunToPos(struct chrdata *chr, struct coord *pos);
 void chrBeginDead(struct chrdata *chr);
 f32 chrGetShield(struct chrdata *chr);
 void chrDie(struct chrdata *chr, s32 aplayernum);
-void chrGoPosGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, s16 *rooms);
+void chrGoPosGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, RoomNum *rooms);
 void chrGoPosClearRestartTtl(struct chrdata *chr);
-void chrPatrolGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, s16 *rooms);
+void chrPatrolGetCurWaypointInfo(struct chrdata *chr, struct coord *pos, RoomNum *rooms);
 struct path *pathFindById(u32 path_id);
 void chrRecordLastVisibleTargetTime(struct chrdata *chr);
 bool chrHasLosToTarget(struct chrdata *chr);
@@ -340,7 +340,7 @@ s16 *teamGetChrIds(s32 team_id);
 s16 *squadronGetChrIds(s32 squadron_id);
 void audioMarkAsRecentlyPlayed(s16 audioid);
 bool audioWasNotPlayedRecently(s16 audioid);
-Gfx *chrsRenderChrStats(Gfx *gdl, s16 *rooms);
+Gfx *chrsRenderChrStats(Gfx *gdl, RoomNum *rooms);
 void chrToggleModelPart(struct chrdata *chr, s32 partnum);
 bool chrIsAvoiding(struct chrdata *chr);
 void chrDrCarollEmitSparks(struct chrdata *chr);
diff --git a/src/include/game/dlights.h b/src/include/game/dlights.h
index 6829cad1b..a52b251ce 100644
--- a/src/include/game/dlights.h
+++ b/src/include/game/dlights.h
@@ -19,7 +19,7 @@ bool lightIsVulnerable(s32 roomnum, s32 lightnum);
 bool lightIsOn(s32 roomnum, s32 lightnum);
 void roomSetFlashBrightness(s32 roomnum, s32 value);
 void roomSetDefaults(struct room *room);
-Gfx *lightsSetForRoom(Gfx *gdl, s16 roomnum);
+Gfx *lightsSetForRoom(Gfx *gdl, RoomNum roomnum);
 Gfx *lightsSetDefault(Gfx *gdl);
 void roomInitLights(s32 roomnum);
 bool lightsHandleHit(struct coord *gunpos, struct coord *hitpos, s32 roomnum);
diff --git a/src/include/game/dyntex.h b/src/include/game/dyntex.h
index 150bb2226..f6c2cd952 100644
--- a/src/include/game/dyntex.h
+++ b/src/include/game/dyntex.h
@@ -7,7 +7,7 @@
 void dyntexTickRoom(s32 roomnum, Vtx *vertices);
 void dyntexAddVertex(Vtx *vertex);
 void dyntexSetCurrentType(s16 type);
-void dyntexSetCurrentRoom(s16 roomnum);
+void dyntexSetCurrentRoom(RoomNum roomnum);
 void dyntexReset(void);
 bool dyntexHasRoom(void);
 
diff --git a/src/include/game/explosions.h b/src/include/game/explosions.h
index 84ae5cc8b..f6d15e212 100644
--- a/src/include/game/explosions.h
+++ b/src/include/game/explosions.h
@@ -8,13 +8,13 @@ void explosionsReset(void);
 
 void explosionsStop(void);
 
-bool explosionCreateSimple(struct prop *prop, struct coord *pos, s16 *rooms, s16 type, s32 playernum);
-bool explosionCreateComplex(struct prop *prop, struct coord *pos, s16 *rooms, s16 type, s32 playernum);
+bool explosionCreateSimple(struct prop *prop, struct coord *pos, RoomNum *rooms, s16 type, s32 playernum);
+bool explosionCreateComplex(struct prop *prop, struct coord *pos, RoomNum *rooms, s16 type, s32 playernum);
 f32 explosionGetHorizontalRangeAtFrame(struct explosion *exp, s32 frame);
 f32 explosionGetVerticalRangeAtFrame(struct explosion *exp, s32 frame);
 void explosionGetBboxAtFrame(struct coord *lower, struct coord *upper, s32 frame, struct prop *prop);
 void explosionAlertChrs(f32 *radius, struct coord *noisepos);
-bool explosionCreate(struct prop *prop, struct coord *pos, s16 *rooms, s16 type, s32 playernum, bool makescorch, struct coord *arg6, s16 room, struct coord *arg8);
+bool explosionCreate(struct prop *prop, struct coord *pos, RoomNum *rooms, s16 type, s32 playernum, bool makescorch, struct coord *arg6, RoomNum room, struct coord *arg8);
 void explosionsUpdateShake(struct coord *arg0, struct coord *arg1, struct coord *arg2);
 bool explosionOverlapsProp(struct explosion *exp, struct prop *prop, struct coord *pos1, struct coord *pos2);
 void explosionInflictDamage(struct prop *prop);
diff --git a/src/include/game/mplayer/scenarios.h b/src/include/game/mplayer/scenarios.h
index d47594e0f..a04f0d021 100644
--- a/src/include/game/mplayer/scenarios.h
+++ b/src/include/game/mplayer/scenarios.h
@@ -26,8 +26,8 @@ void scenarioTick(void);
 void scenarioTickChr(struct chrdata *chr);
 Gfx *scenarioRadarExtra(Gfx *gdl);
 bool scenarioRadarChr(Gfx **gdl, struct prop *prop);
-f32 scenarioChooseSpawnLocation(f32 chrradius, struct coord *pos, s16 *rooms, struct prop *prop);
+f32 scenarioChooseSpawnLocation(f32 chrradius, struct coord *pos, RoomNum *rooms, struct prop *prop);
 s32 scenarioGetMaxTeams(void);
-void scenarioHighlightRoom(s16 room, s32 *arg1, s32 *arg2, s32 *arg3);
+void scenarioHighlightRoom(RoomNum room, s32 *arg1, s32 *arg2, s32 *arg3);
 
 #endif
diff --git a/src/include/game/mplayer/setup.h b/src/include/game/mplayer/setup.h
index b8c21972a..00d42360b 100644
--- a/src/include/game/mplayer/setup.h
+++ b/src/include/game/mplayer/setup.h
@@ -81,11 +81,11 @@ Gfx *htbRenderHud(Gfx *gdl);
 void ctcInitProps(void);
 bool ctcHighlightProp(struct prop *prop, s32 *colour);
 void ctcAddPad(s32 *cmd);
-void ctcHighlightRoom(s16 roomnum, s32 *arg1, s32 *arg2, s32 *arg3);
+void ctcHighlightRoom(RoomNum roomnum, s32 *arg1, s32 *arg2, s32 *arg3);
 void kohTick(void);
 Gfx *kohRenderHud(Gfx *gdl);
 void kohAddHill(s32 *cmd);
-void kohHighlightRoom(s16 roomnum, s32 *arg1, s32 *arg2, s32 *arg3);
+void kohHighlightRoom(RoomNum roomnum, s32 *arg1, s32 *arg2, s32 *arg3);
 void htmAddPad(s16 padnum);
 void htmReset(void);
 void htbCreateUplink(void);
diff --git a/src/include/game/objectives.h b/src/include/game/objectives.h
index 438eb1782..fa13c3834 100644
--- a/src/include/game/objectives.h
+++ b/src/include/game/objectives.h
@@ -27,7 +27,7 @@ void objectivesDisableChecking(void);
 void objectivesShowHudmsg(char *buffer, s32 hudmsgtype);
 void objectivesCheckAll(void);
 void objectiveCheckRoomEntered(s32 currentroom);
-void objectiveCheckThrowInRoom(s32 arg0, s16 *requiredrooms);
+void objectiveCheckThrowInRoom(s32 arg0, RoomNum *requiredrooms);
 void objectiveCheckHolograph(f32 sqdist);
 struct prop *chopperGetTargetProp(struct chopperobj *heli);
 struct defaultobj *objFindByTagId(s32 tag_id);
diff --git a/src/include/game/padhalllv.h b/src/include/game/padhalllv.h
index 924da841d..9d4306c29 100644
--- a/src/include/game/padhalllv.h
+++ b/src/include/game/padhalllv.h
@@ -5,7 +5,7 @@
 #include "types.h"
 
 void navSetSeed(u32 upper, u32 lower);
-struct waypoint *waypointFindClosestToPos(struct coord *pos, s16 *rooms);
+struct waypoint *waypointFindClosestToPos(struct coord *pos, RoomNum *rooms);
 struct waygroup *waygroupChooseNeighbour(s32 *groupnums, s32 step, u32 ignoremask);
 void waygroupSetStepIfUndiscovered(s32 *groupnums, s32 step, u32 ignoremask);
 bool waygroupDiscoverOneStep(struct waygroup *group, s32 step, u32 ignoremask);
diff --git a/src/include/game/player.h b/src/include/game/player.h
index b012a1654..81840b813 100644
--- a/src/include/game/player.h
+++ b/src/include/game/player.h
@@ -4,8 +4,8 @@
 #include "data.h"
 #include "types.h"
 
-f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, s16 *dstrooms, struct prop *prop, s16 *spawnpads, s32 numspawnpads);
-f32 playerChooseGeneralSpawnLocation(f32 chrradius, struct coord *pos, s16 *rooms, struct prop *prop);
+f32 playerChooseSpawnLocation(f32 chrradius, struct coord *dstpos, RoomNum *dstrooms, struct prop *prop, s16 *spawnpads, s32 numspawnpads);
+f32 playerChooseGeneralSpawnLocation(f32 chrradius, struct coord *pos, RoomNum *rooms, struct prop *prop);
 void playerStartNewLife(void);
 void playerLoadDefaults(void);
 bool playerSpawnAnti(struct chrdata *chr, s32 param_2);
@@ -63,7 +63,7 @@ void playerDie(bool force);
 void playerDieByShooter(u32 shooter, bool force);
 void playerCheckIfShotInBack(s32 attackerplayernum, f32 x, f32 z);
 f32 playerGetHealthBarHeightFrac(void);
-void player0f0c1840(struct coord *pos, struct coord *up, struct coord *look, struct coord *pos2, s16 *rooms);
+void player0f0c1840(struct coord *pos, struct coord *up, struct coord *look, struct coord *pos2, RoomNum *rooms);
 void player0f0c1ba4(struct coord *pos, struct coord *up, struct coord *look, struct coord *memcampos, s32 memcamroom);
 void player0f0c1bd8(struct coord *pos, struct coord *up, struct coord *look);
 void playersClearMemCamRoom(void);
diff --git a/src/include/game/prop.h b/src/include/game/prop.h
index 5076414a6..b26589518 100644
--- a/src/include/game/prop.h
+++ b/src/include/game/prop.h
@@ -21,7 +21,7 @@ void propDelist(struct prop *prop);
 void propReparent(struct prop *mover, struct prop *adopter);
 void propDetach(struct prop *prop);
 Gfx *propRender(Gfx *gdl, struct prop *prop, bool xlupass);
-Gfx *propsRender(Gfx *gdl, s16 renderroomnum, s32 renderpass, s16 *roomnumsbyprop);
+Gfx *propsRender(Gfx *gdl, RoomNum renderroomnum, s32 renderpass, RoomNum *roomnumsbyprop);
 void weaponPlayWhooshSound(s32 weaponnum, struct prop *prop);
 void func0f060bac(s32 weaponnum, struct prop *prop);
 struct prop *shotCalculateHits(s32 handnum, bool arg1, struct coord *arg2, struct coord *arg3, struct coord *gunpos, struct coord *dir, u32 arg6, f32 arg7, bool arg8);
@@ -46,21 +46,21 @@ void farsightChooseTarget(void);
 void autoaimTick(void);
 u32 propDoorGetCdTypes(struct prop *prop);
 bool propIsOfCdType(struct prop *prop, u32 types);
-void roomsCopy(s16 *srcrooms, s16 *dstrooms);
-void roomsAppend(s16 *newrooms, s16 *dstrooms, s32 maxlen);
-bool arrayIntersects(s16 *a, s16 *b);
+void roomsCopy(RoomNum *srcrooms, RoomNum *dstrooms);
+void roomsAppend(RoomNum *newrooms, RoomNum *dstrooms, s32 maxlen);
+bool arrayIntersects(RoomNum *a, RoomNum *b);
 bool propTryAddToChunk(s16 propnum, s32 chunkindex);
 s32 roomAllocatePropListChunk(s32 room, s32 arg1);
-void propRegisterRoom(struct prop *prop, s16 room);
-void propDeregisterRoom(struct prop *prop, s16 room);
+void propRegisterRoom(struct prop *prop, RoomNum room);
+void propDeregisterRoom(struct prop *prop, RoomNum room);
 void propDeregisterRooms(struct prop *prop);
 void propRegisterRooms(struct prop *prop);
-void func0f065d1c(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms, s16 *morerooms, u32 arg5);
-void func0f065dd8(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms);
-void func0f065dfc(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms, s16 *morerooms, u32 arg5);
-void func0f065e74(struct coord *pos, s16 *rooms, struct coord *newpos, s16 *newrooms);
-void func0f065e98(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2);
-void roomGetProps(s16 *room, s16 *propnums, s32 len);
+void func0f065d1c(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms, RoomNum *morerooms, u32 arg5);
+void func0f065dd8(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms);
+void func0f065dfc(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms, RoomNum *morerooms, u32 arg5);
+void func0f065e74(struct coord *pos, RoomNum *rooms, struct coord *newpos, RoomNum *newrooms);
+void func0f065e98(struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2);
+void roomGetProps(RoomNum *room, s16 *propnums, s32 len);
 void propsDefragRoomProps(void);
 void propGetBbox(struct prop *prop, f32 *radius, f32 *ymax, f32 *ymin);
 bool propUpdateGeometry(struct prop *prop, u8 **start, u8 **end);
diff --git a/src/include/game/propobj.h b/src/include/game/propobj.h
index ba17e8f0f..304947f69 100644
--- a/src/include/game/propobj.h
+++ b/src/include/game/propobj.h
@@ -63,7 +63,7 @@ bool modelGetScreenCoords2(struct model *model, f32 *x2, f32 *x1, f32 *y2, f32 *
 bool modelGetScreenCoords(struct model *model, f32 *x2, f32 *x1, f32 *y2, f32 *y1);
 void func0f06803c(struct coord *arg0, f32 *arg1, f32 *arg2, f32 *arg3, f32 *arg4);
 struct defaultobj *objFindByPadNum(s32 padnum);
-struct defaultobj *objFindByPos(struct coord *pos, s16 *rooms);
+struct defaultobj *objFindByPos(struct coord *pos, RoomNum *rooms);
 void projectileFree(struct projectile *projectile);
 void projectilesUnrefOwner(struct prop *owner);
 void projectileReset(struct projectile *projectile);
@@ -81,7 +81,7 @@ struct modelnode *modelFindBboxNode(struct model *model);
 struct modelrodata_bbox *modelFindBboxRodata(struct model *model);
 struct modelnode *objFindBboxNode(struct defaultobj *obj);
 struct modelrodata_bbox *objFindBboxRodata(struct defaultobj *obj);
-s32 objGetAverageBrightnessInRooms(s16 *rooms, s32 arg1);
+s32 objGetAverageBrightnessInRooms(RoomNum *rooms, s32 arg1);
 s32 door0f068c04(struct prop *prop, s32 *arg1, s32 *arg2);
 s32 func0f068fc8(struct prop *prop, bool arg1);
 void propCalculateShadeColour(struct prop *prop, u8 *nextcol, u16 floorcol);
@@ -98,10 +98,10 @@ void objCreateDebris(struct defaultobj *obj, struct prop *prop);
 struct prop *objInit(struct defaultobj *obj, struct modeldef *modeldef, struct prop *prop, struct model *model);
 struct prop *objInitWithModelDef(struct defaultobj *obj, struct modeldef *modeldef);
 struct prop *objInitWithAutoModel(struct defaultobj *obj);
-void func0f06a580(struct defaultobj *obj, struct coord *pos, Mtxf *matrix, s16 *rooms);
+void func0f06a580(struct defaultobj *obj, struct coord *pos, Mtxf *matrix, RoomNum *rooms);
 f32 func0f06a620(struct defaultobj *obj);
-void func0f06a730(struct defaultobj *obj, struct coord *arg1, Mtxf *matrix, s16 *rooms, struct coord *arg4);
-void func0f06ab60(struct defaultobj *obj, struct coord *arg1, Mtxf *matrix, s16 *rooms, struct coord *arg4);
+void func0f06a730(struct defaultobj *obj, struct coord *arg1, Mtxf *matrix, RoomNum *rooms, struct coord *arg4);
+void func0f06ab60(struct defaultobj *obj, struct coord *arg1, Mtxf *matrix, RoomNum *rooms, struct coord *arg4);
 void objFreeProjectile(struct defaultobj *obj);
 void objFreeEmbedmentOrProjectile(struct prop *prop);
 void objFree(struct defaultobj *obj, bool freeprop, bool canregen);
@@ -112,7 +112,7 @@ bool func0f06b488(struct prop *prop, struct coord *arg1, struct coord *arg2, str
 bool func0f06b610(struct defaultobj *obj, struct coord *arg1, struct coord *arg2, struct coord *arg3, f32 arg4, struct coord *arg5, struct coord *arg6, struct coord *arg7, struct coord *arg8, f32 *arg9);
 bool func0f06bea0(struct model *model, struct modelnode *arg1, struct modelnode *arg2, struct coord *arg3, struct coord *arg4, void *arg5, f32 *arg6, struct modelnode **arg7, s32 *hitpart, s32 *arg9, struct modelnode **arg10);
 bool func0f06c28c(struct chrdata *chr, struct coord *arg1, struct coord *arg2, struct coord *arg3, f32 arg4, struct coord *arg5, struct coord *arg6, struct coord *arg7, struct coord *arg8, f32 *arg9);
-bool projectileFindCollidingProp(struct prop *prop, struct coord *pos, struct coord *arg2, u32 cdtypes, struct coord *arg4, struct coord *arg5, s16 *arg6);
+bool projectileFindCollidingProp(struct prop *prop, struct coord *pos, struct coord *arg2, u32 cdtypes, struct coord *arg4, struct coord *arg5, RoomNum *rooms);
 s32 func0f06cd00(struct defaultobj *obj, struct coord *pos, struct coord *arg2, struct coord *arg3);
 bool func0f06d37c(struct defaultobj *obj, struct coord *arg1, struct coord *arg2, struct coord *arg3);
 void applySpeed(f32 *distdone, f32 maxdist, f32 *speed, f32 accel, f32 decel, f32 maxspeed);
@@ -142,7 +142,7 @@ f32 liftGetY(struct liftobj *lift);
 void liftUpdateTiles(struct liftobj *lift, bool stationary);
 void liftGoToStop(struct liftobj *lift, s32 stopnum);
 f32 objGetHov04(struct defaultobj *obj);
-void hovUpdateGround(struct defaultobj *obj, struct hov *hov, struct coord *pos, s16 *rooms, f32 matrix[3][3]);
+void hovUpdateGround(struct defaultobj *obj, struct hov *hov, struct coord *pos, RoomNum *rooms, f32 matrix[3][3]);
 void hovTick(struct defaultobj *obj, struct hov *hov);
 s32 objIsHoverpropOrBike(struct defaultobj *obj);
 f32 hoverpropGetTurnAngle(struct defaultobj *obj);
@@ -289,7 +289,7 @@ void weaponDeleteFromChr(struct chrdata *chr, s32 hand);
 struct prop *weaponCreateForChr(struct chrdata *chr, s32 modelnum, s32 weaponnum, u32 flags, struct weaponobj *obj, struct modeldef *modeldef);
 struct prop *chrGiveWeapon(struct chrdata *chr, s32 model, s32 weaponnum, u32 flags);
 s32 weaponTestForPickup(struct prop *prop);
-void weaponSetGunfireVisible(struct prop *prop, bool visible, s16 room);
+void weaponSetGunfireVisible(struct prop *prop, bool visible, RoomNum room);
 bool weaponIsGunfireVisible(struct prop *prop);
 s32 hatGetType(struct prop *prop);
 bool doorIsUnlocked(struct prop *playerprop, struct prop *doorprop);
@@ -306,7 +306,7 @@ void func0f08d3dc(struct doorobj *door);
 void func0f08d460(struct doorobj *door);
 void doorActivatePortal(struct doorobj *door);
 void doorDeactivatePortal(struct doorobj *door);
-struct prop *doorInit(struct doorobj *door, struct coord *pos, Mtxf *mtx, s16 *rooms, struct coord *coord, struct coord *centre);
+struct prop *doorInit(struct doorobj *door, struct coord *pos, Mtxf *mtx, RoomNum *rooms, struct coord *coord, struct coord *centre);
 void doorPlayOpeningSound(s32 soundtype, struct prop *prop);
 void doorPlayClosingSound(s32 soundtype, struct prop *prop);
 void doorPlayOpenedSound(s32 soundtype, struct prop *prop);
@@ -320,7 +320,7 @@ void doorSetMode(struct doorobj *door, s32 newmode);
 void doorsRequestMode(struct doorobj *door, s32 newmode);
 s32 doorIsClosed(struct doorobj *door);
 s32 doorIsOpen(struct doorobj *door);
-s32 func0f08e5a8(s16 *rooms, struct screenbox *box);
+s32 func0f08e5a8(RoomNum *rooms, struct screenbox *box);
 f32 objCalculateFadeDistOpacityFrac(struct prop *prop, f32 modelscale);
 bool posIsInObjFadeDistance(struct coord *coord, f32 modelscale);
 bool func0f08e8ac(struct prop *prop, struct coord *pos, f32 arg2, bool arg3);
diff --git a/src/include/game/propsnd.h b/src/include/game/propsnd.h
index f08196bf5..d1b236033 100644
--- a/src/include/game/propsnd.h
+++ b/src/include/game/propsnd.h
@@ -21,17 +21,17 @@ void psTick(void);
 void psSetPitch(struct prop *prop, f32 targetpitch, s32 changespeed);
 void psSetVolume(struct prop *prop, s32 vol);
 void psStopOneShootChannel(struct prop *prop);
-s16 psCreate(struct pschannel *channel, struct prop *prop, s16 soundnum, s16 padnum, s32 vol, u16 flags, u16 flags2, s32 type, struct coord *pos, f32 pitch, s16 *rooms, s32 room, f32 dist1, f32 dist2, f32 dist3);
+s16 psCreate(struct pschannel *channel, struct prop *prop, s16 soundnum, s16 padnum, s32 vol, u16 flags, u16 flags2, s32 type, struct coord *pos, f32 pitch, RoomNum *rooms, s32 room, f32 dist1, f32 dist2, f32 dist3);
 s32 psPlayFromProp(s32 channelnum, s16 soundnum, s32 vol, struct prop *prop, s16 type, u16 flags);
 void psMuteChannel(s32 channelnum);
 bool psIsChannelFree(s32 channelnum);
 void psModify(s32 channelnum, s32 arg1, s16 padnum, struct prop *prop, s32 volchangetimer60, s32 dist2, s32 dist3, u16 flags);
-s32 psCalculateVol(struct coord *pos, f32 arg1, f32 arg2, f32 arg3, s16 *rooms, s16 soundnum, s32 arg6, f32 *arg7);
+s32 psCalculateVol(struct coord *pos, f32 arg1, f32 arg2, f32 arg3, RoomNum *rooms, s16 soundnum, s32 arg6, f32 *arg7);
 s32 psCalculatePan3(s32 degrees, f32 arg1, struct pschannel *channel);
 s32 psCalculatePan2(struct coord *pos, s32 arg1, f32 arg2, struct pschannel *channel);
 s32 psCalculatePan(struct coord *pos, f32 dist1, f32 dist2, f32 dist3, f32 playerdist, bool arg5, struct pschannel *channel);
-void psGetTheoreticalVolPan(struct coord *pos, s16 *rooms, s16 soundnum, s32 *vol, s32 *pan);
-void psApplyVolPan(struct sndstate *handle, struct coord *pos, f32 dist1, f32 dist2, f32 dist3, s16 *rooms, s16 soundnum, s32 arg7, f32 *distanceptr);
+void psGetTheoreticalVolPan(struct coord *pos, RoomNum *rooms, s16 soundnum, s32 *vol, s32 *pan);
+void psApplyVolPan(struct sndstate *handle, struct coord *pos, f32 dist1, f32 dist2, f32 dist3, RoomNum *rooms, s16 soundnum, s32 arg7, f32 *distanceptr);
 s32 psGetRandomSparkSound(void);
 s32 psGetDuration60(s32 channelnum);
 
diff --git a/src/include/game/setuputils.h b/src/include/game/setuputils.h
index 4d4fcb77a..86cad9dea 100644
--- a/src/include/game/setuputils.h
+++ b/src/include/game/setuputils.h
@@ -11,7 +11,7 @@ u32 setupGetCmdIndexByProp(struct prop *prop);
 bool setupLoadModeldef(s32 modelnum);
 bool setupGetObjBbox(struct defaultobj *obj, struct coord *pos, f32 realrot[3][3], struct coord *arg3, struct coord *arg4);
 bool setup0f092304(struct defaultobj *obj, struct coord *arg1, struct coord *arg2);
-void setup0f09233c(struct defaultobj *obj, struct coord *pos, f32 realrot[3][3], s16 *rooms);
+void setup0f09233c(struct defaultobj *obj, struct coord *pos, f32 realrot[3][3], RoomNum *rooms);
 void setup0f0923d4(struct defaultobj *obj);
 struct defaultobj *setupGetObjByCmdIndex(u32 cmdindex);
 struct defaultobj *setupFindObjForReuse(s32 type, struct defaultobj **arg1, struct defaultobj **arg2, bool musthaveprop, bool musthavemodel, struct modeldef *modeldef);
diff --git a/src/include/game/smoke.h b/src/include/game/smoke.h
index 790c272cf..221ecda59 100644
--- a/src/include/game/smoke.h
+++ b/src/include/game/smoke.h
@@ -11,13 +11,13 @@ void smokeReset(void);
 void smokeStop(void);
 
 Gfx *smokeRenderPart(struct smoke *smoke, struct smokepart *part, Gfx *gdl, struct coord *coord, f32 size);
-struct smoke *smokeCreate(struct coord *pos, s16 *rooms, s16 type);
-bool smokeCreateForHand(struct coord *pos, s16 *rooms, s16 type, s32 handnum);
-bool smokeCreateWithSource(void *source, struct coord *pos, s16 *rooms, s16 type, bool srcispadeffect);
+struct smoke *smokeCreate(struct coord *pos, RoomNum *rooms, s16 type);
+bool smokeCreateForHand(struct coord *pos, RoomNum *rooms, s16 type, s32 handnum);
+bool smokeCreateWithSource(void *source, struct coord *pos, RoomNum *rooms, s16 type, bool srcispadeffect);
 void smokeCreateAtProp(struct prop *prop, s16 type);
-void smokeCreateAtPadEffect(struct padeffectobj *effect, struct coord *pos, s16 *rooms, s16 type);
+void smokeCreateAtPadEffect(struct padeffectobj *effect, struct coord *pos, RoomNum *rooms, s16 type);
 void smokeClearForProp(struct prop *prop);
-struct smoke *smokeCreateSimple(struct coord *pos, s16 *rooms, s16 type);
+struct smoke *smokeCreateSimple(struct coord *pos, RoomNum *rooms, s16 type);
 u32 smokeTick(struct prop *prop);
 u32 smokeTickPlayer(struct prop *prop);
 Gfx *smokeRender(struct prop *prop, Gfx *gdl, bool xlupass);
diff --git a/src/include/game/wallhit.h b/src/include/game/wallhit.h
index 36fe0e25b..9866462ee 100644
--- a/src/include/game/wallhit.h
+++ b/src/include/game/wallhit.h
@@ -17,11 +17,11 @@ void wallhitRemoveOne(void);
 void wallhitsTick(void);
 
 void wallhitCreate(struct coord *relpos, struct coord *arg1, struct coord *arg2, s16 arg3[3],
-		s16 arg4[3], s16 texnum, s16 room, struct prop *objprop,
+		s16 arg4[3], s16 texnum, RoomNum room, struct prop *objprop,
 		s8 mtxindex, s8 arg9, struct chrdata *chr, bool xlu);
 
 void wallhitCreateWith20Args(struct coord *relpos, struct coord *arg1, struct coord *arg2, s16 arg3[3],
-		s16 arg4[3], s16 texnum, s16 room, struct prop *objprop,
+		s16 arg4[3], s16 texnum, RoomNum room, struct prop *objprop,
 		struct prop *chrprop, s8 mtxindex, s8 arg10, struct chrdata *chr,
 		f32 width, f32 height, u8 minalpha, u8 maxalpha,
 		s32 rotdeg, u32 timermax, u32 timerspeed, bool xlu);
diff --git a/src/include/lib/collision.h b/src/include/lib/collision.h
index 657659d4a..a227b2331 100644
--- a/src/include/lib/collision.h
+++ b/src/include/lib/collision.h
@@ -25,47 +25,47 @@ bool cd000266a4(f32 x, f32 z, struct geo *tile);
 void cdGetPropsOnPlatform(struct prop *platform, s16 *propnums, s32 len);
 s32 cd000274e0Block(struct geoblock *tile, f32 x, f32 z, f32 width, struct prop *prop, struct collision *collision);
 bool cd000276c8Cyl(struct geocyl *tile, f32 x, f32 z, f32 width, struct prop *prop, struct collision *collision);
-bool cdFindLadder(struct coord *pos, f32 width, f32 ymax, f32 ymin, s16 *rooms, u16 geoflags, struct coord *laddernormal);
-bool cd0002a13c(struct coord *pos, f32 radius, f32 arg2, f32 arg3, s16 *rooms, u16 geoflags);
-f32 cdFindGroundInfoAtCyl(struct coord *pos, f32 radius, s16 *rooms, u16 *floorcol, u8 *floortype, u16 *floorflags, s16 *floorroom, s32 *inlift, struct prop **lift);
+bool cdFindLadder(struct coord *pos, f32 width, f32 ymax, f32 ymin, RoomNum *rooms, u16 geoflags, struct coord *laddernormal);
+bool cd0002a13c(struct coord *pos, f32 radius, f32 arg2, f32 arg3, RoomNum *rooms, u16 geoflags);
+f32 cdFindGroundInfoAtCyl(struct coord *pos, f32 radius, RoomNum *rooms, u16 *floorcol, u8 *floortype, u16 *floorflags, RoomNum *floorroom, s32 *inlift, struct prop **lift);
 f32 cdReturnZero(void);
-f32 cdFindGroundAtCyl(struct coord *pos, f32 radius, s16 *rooms, u16 *floorcol, u8 *floortype);
-f32 cdFindFloorYColourTypeAtPos(struct coord *pos, s16 *rooms, u16 *floorcol, u8 *floortype);
-s32 cdFindFloorRoomAtPos(struct coord *pos, s16 *nearrooms);
+f32 cdFindGroundAtCyl(struct coord *pos, f32 radius, RoomNum *rooms, u16 *floorcol, u8 *floortype);
+f32 cdFindFloorYColourTypeAtPos(struct coord *pos, RoomNum *rooms, u16 *floorcol, u8 *floortype);
+s32 cdFindFloorRoomAtPos(struct coord *pos, RoomNum *nearrooms);
 
 #if VERSION >= VERSION_NTSC_1_0
-s16 cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr);
-s16 cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr);
+RoomNum cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr);
+RoomNum cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr);
 #else
-s16 cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr);
-s16 cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr);
+RoomNum cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr);
+RoomNum cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr);
 #endif
 
-s16 cdFindFloorRoomYColourNormalPropAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcol, struct coord *normal, struct prop **propptr);
-s16 cdFindCeilingRoomYColourFlagsNormalAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcol, u16 *geoflags, struct coord *normal);
-s32 cdTestVolume(struct coord *pos, f32 radius, s16 *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin);
-s32 cdExamCylMove01(struct coord *pos, struct coord *pos2, f32 radius, s16 *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin);
-s32 cdExamCylMove02(struct coord *origpos, struct coord *dstpos, f32 width, s16 *dstrooms, s32 types, bool checkvertical, f32 ymax, f32 ymin);
-bool cdTestCylMove01(struct coord *pos, s16 *rooms, struct coord *targetpos, u32 types, u32 arg4, f32 ymax, f32 ymin);
-s32 cdTestCylMove02(struct coord *pos, s16 *rooms, struct coord *coord2, s16 *rooms2, u32 types, bool arg5, f32 ymax, f32 ymin);
-s32 cdExamCylMove03(struct coord *pos, s16 *rooms, struct coord *arg2, u32 types, u32 arg4, f32 ymax, f32 ymin);
-s32 cdTestCylMove04(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin);
-s32 cdExamCylMove05(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2, s32 types, bool arg5, f32 ymax, f32 ymin);
-s32 cdExamCylMove06(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, f32 arg4, s32 types, s32 arg6, f32 ymax, f32 ymin);
-s32 cdExamCylMove07(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin);
-s32 cdExamCylMove08(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, f32 width, u32 types, s32 arg6, f32 ymax, f32 ymin);
-bool cdTestLos03(struct coord *viewpos, s16 *rooms, struct coord *targetpos, u32 types, u16 geoflags);
-bool cdTestLos04(struct coord *coord, s16 *rooms, struct coord *coord2, s32 arg3);
-bool cdTestLos05(struct coord *coord, s16 *rooms, struct coord *coord2, s16 *rooms2, s32 cdtypes, u16 geoflags);
-bool cdTestLos06(struct coord *arg0, s16 *rooms1, struct coord *arg2, s16 *rooms2, u32 types);
-bool cdTestLos07(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2, s16 *rooms3, u32 types, u16 geoflags);
-s32 cdExamLos08(struct coord *pos, s16 *rooms, struct coord *pos2, u32 types, u16 geoflags);
-s32 cdExamLos09(struct coord *pos, s16 *rooms, struct coord *pos2, u32 types);
-s32 cdTestLos10(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types, u16 geoflags);
-s32 cdTestLos11(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types);
+RoomNum cdFindFloorRoomYColourNormalPropAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcol, struct coord *normal, struct prop **propptr);
+RoomNum cdFindCeilingRoomYColourFlagsNormalAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcol, u16 *geoflags, struct coord *normal);
+s32 cdTestVolume(struct coord *pos, f32 radius, RoomNum *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin);
+s32 cdExamCylMove01(struct coord *pos, struct coord *pos2, f32 radius, RoomNum *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin);
+s32 cdExamCylMove02(struct coord *origpos, struct coord *dstpos, f32 width, RoomNum *dstrooms, s32 types, bool checkvertical, f32 ymax, f32 ymin);
+bool cdTestCylMove01(struct coord *pos, RoomNum *rooms, struct coord *targetpos, u32 types, u32 arg4, f32 ymax, f32 ymin);
+s32 cdTestCylMove02(struct coord *pos, RoomNum *rooms, struct coord *coord2, RoomNum *rooms2, u32 types, bool arg5, f32 ymax, f32 ymin);
+s32 cdExamCylMove03(struct coord *pos, RoomNum *rooms, struct coord *arg2, u32 types, u32 arg4, f32 ymax, f32 ymin);
+s32 cdTestCylMove04(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin);
+s32 cdExamCylMove05(struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2, s32 types, bool arg5, f32 ymax, f32 ymin);
+s32 cdExamCylMove06(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, f32 arg4, s32 types, s32 arg6, f32 ymax, f32 ymin);
+s32 cdExamCylMove07(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin);
+s32 cdExamCylMove08(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, f32 width, u32 types, s32 arg6, f32 ymax, f32 ymin);
+bool cdTestLos03(struct coord *viewpos, RoomNum *rooms, struct coord *targetpos, u32 types, u16 geoflags);
+bool cdTestLos04(struct coord *coord, RoomNum *rooms, struct coord *coord2, s32 arg3);
+bool cdTestLos05(struct coord *coord, RoomNum *rooms, struct coord *coord2, RoomNum *rooms2, s32 cdtypes, u16 geoflags);
+bool cdTestLos06(struct coord *arg0, RoomNum *rooms1, struct coord *arg2, RoomNum *rooms2, u32 types);
+bool cdTestLos07(struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2, RoomNum *rooms3, u32 types, u16 geoflags);
+s32 cdExamLos08(struct coord *pos, RoomNum *rooms, struct coord *pos2, u32 types, u16 geoflags);
+s32 cdExamLos09(struct coord *pos, RoomNum *rooms, struct coord *pos2, u32 types);
+s32 cdTestLos10(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types, u16 geoflags);
+s32 cdTestLos11(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types);
 bool cd0002ded8(struct coord *arg0, struct coord *arg1, struct prop *prop);
-s32 cdTestBlockOverlapsAnyProp(struct geoblock *geo, s16 *rooms, u32 types);
-s32 cd0002f02c(struct geoblock *block, s16 *rooms, s32 types);
-bool cdIsNearlyInSight(struct coord *viewpos, s16 *rooms, struct coord *targetpos, f32 distance, s32 arg4);
+s32 cdTestBlockOverlapsAnyProp(struct geoblock *geo, RoomNum *rooms, u32 types);
+s32 cd0002f02c(struct geoblock *block, RoomNum *rooms, s32 types);
+bool cdIsNearlyInSight(struct coord *viewpos, RoomNum *rooms, struct coord *targetpos, f32 distance, s32 arg4);
 
 #endif
diff --git a/src/include/lib/lib_17ce0.h b/src/include/lib/lib_17ce0.h
index 5fa8ddb14..a6d970059 100644
--- a/src/include/lib/lib_17ce0.h
+++ b/src/include/lib/lib_17ce0.h
@@ -9,8 +9,8 @@
 #define PORTALINTERSECTION_FRONTTOBEHIND 2
 
 void portalGetAvgVertexPos(s32 portalnum, struct coord *avg);
-void portal00017dc4(s16 *rooms, s16 roomnum);
+void portal00017dc4(RoomNum *rooms, RoomNum roomnum);
 s32 portalCalculateIntersection(s32 portalnum, struct coord *pos1, struct coord *pos2);
-void portal00018148(struct coord *pos, struct coord *pos2, s16 *rooms, s16 *arg3, s16 *arg4, s32 arg5);
+void portal00018148(struct coord *pos, struct coord *pos2, RoomNum *rooms, RoomNum *arg3, RoomNum *arg4, s32 arg5);
 
 #endif
diff --git a/src/include/types.h b/src/include/types.h
index b2a522a4c..9d9929c51 100644
--- a/src/include/types.h
+++ b/src/include/types.h
@@ -19,6 +19,7 @@ typedef s32 PakErr1;
 typedef s32 PakErr2;
 typedef s32 MenuDialogHandlerResult;
 typedef intptr_t MenuItemHandlerResult;
+typedef s16 RoomNum;
 
 // Float version of a graphics matrix, which has higher precision than an Mtx.
 // Matrices are stored as Mtxfs then converted to an Mtx when passed to the GPU.
@@ -292,7 +293,7 @@ struct prop {
 	/*0x1c*/ struct prop *child;
 	/*0x20*/ struct prop *next;
 	/*0x24*/ struct prop *prev;
-	/*0x28*/ s16 rooms[8];
+	/*0x28*/ RoomNum rooms[8];
 	/*0x38*/ u16 lastupdateframe;
 	/*0x3a*/ u16 propupdate240;
 	/*0x3c*/ u8 propupdate60err;
@@ -738,7 +739,7 @@ struct aibot {
 	/*0x076*/ s16 lastkilledbyplayernum;
 	/*0x078*/ u8 forceslowupdates;
 	/*0x079*/ u8 command;
-	/*0x07a*/ s16 defendholdrooms[1];
+	/*0x07a*/ RoomNum defendholdrooms[1];
 	/*0x07c*/ u32 unk07c; // unused
 	/*0x080*/ u32 unk080; // unused
 	/*0x084*/ u32 unk084; // unused
@@ -770,7 +771,7 @@ struct aibot {
 	/*0x0e0*/ s16 reaperspeed[2];
 	/*0x0e4*/ f32 maulercharge[2];
 	/*0x0ec*/ struct coord gotopos;
-	/*0x0f8*/ s16 gotorooms[8];
+	/*0x0f8*/ RoomNum gotorooms[8];
 	/*0x108*/ struct coord shotspeed; // "boost" when aibot is shot
 	/*0x114*/ s32 feudplayernum;
 	/*0x118*/ s32 commandtimer60;
@@ -783,7 +784,7 @@ struct aibot {
 	/*0x13c*/ f32 chrdistances[MAX_MPCHRS];
 	/*0x16c*/ u8 chrsinsight[MAX_MPCHRS];
 	/*0x178*/ s32 chrslastseen60[MAX_MPCHRS];
-	/*0x1a8*/ s16 chrrooms[MAX_MPCHRS];
+	/*0x1a8*/ RoomNum chrrooms[MAX_MPCHRS];
 	/*0x1c0*/ f32 extraangle;
 	/*0x1c4*/ f32 extraanglerate;
 	/*0x1c8*/ f32 extraanglebase;
@@ -1040,7 +1041,7 @@ struct act_patrol {
 
 struct act_gopos {
 	/*0x02c*/ struct coord endpos;
-	/*0x038*/ s16 endrooms[8];
+	/*0x038*/ RoomNum endrooms[8];
 	/*0x048*/ struct waypoint *target; // Target/final waypoint
 
 	// Array of pointers to the next couple of waypoints. Recalculated each time
@@ -1243,9 +1244,9 @@ struct chrdata {
 	/*0x2ae*/ u16 unk2ae;
 	/*0x2b0*/ u8 tude;
 	/*0x2b1*/ u8 voicebox;
-	/*0x2b2*/ s16 floorroom;
+	/*0x2b2*/ RoomNum floorroom;
 	/*0x2b4*/ u32 unk2b4;
-	/*0x2b8*/ s16 oldrooms[8];
+	/*0x2b8*/ RoomNum oldrooms[8];
 	/*0x2c8*/ struct coord runfrompos;
 	/*0x2d4*/ struct aibot *aibot;
 	/*0x2d8*/ s16 blurdrugamount;
@@ -2463,7 +2464,7 @@ struct player {
 	/*0x0278*/ f32 shieldshowrot;
 	/*0x027c*/ u32 shieldshowrnd;
 	/*0x0280*/ f32 shieldshowtime;
-	/*0x0284*/ s16 bondprevrooms[8];
+	/*0x0284*/ RoomNum bondprevrooms[8];
 	/*0x0294*/ f32 liftground;
 	/*0x0298*/ struct prop *lift;
 	/*0x029c*/ f32 ladderupdown;
@@ -2659,7 +2660,7 @@ struct player {
 	/*0x19a4*/ f32 speedgo;
 	/*0x19a8*/ s32 sighttimer240;
 	/*0x19ac*/ s32 crouchoffsetreal;
-	/*0x19b0*/ s16 floorroom;
+	/*0x19b0*/ RoomNum floorroom;
 	/*0x19b2*/ u8 unk19b2;
 	/*0x19b3*/ u8 dostartnewlife;
 	/*0x19b4*/ f32 crouchoffsetsmall;
@@ -2805,7 +2806,7 @@ struct coverdefinition {
 struct cover {
 	/*0x00*/ struct coord *pos;
 	/*0x04*/ struct coord *look;
-	/*0x08*/ s16 rooms[2];
+	/*0x08*/ RoomNum rooms[2];
 	/*0x0c*/ u16 flags;
 };
 
@@ -4423,7 +4424,7 @@ struct scenariodata_koh {
 	/*0x800ac118*/ s16 movehill;
 	/*0x800ac11a*/ s16 hillindex;
 	/*0x800ac11c*/ s16 hillcount;
-	/*0x800ac11e*/ s16 hillrooms[2];
+	/*0x800ac11e*/ RoomNum hillrooms[2];
 	/*0x800ac122*/ s16 hillpads[9];
 	/*0x800ac134*/ struct coord hillpos;
 	/*0x800ac140*/ f32 colourfracr;
@@ -4440,7 +4441,7 @@ struct ctcspawnpadsperteam {
 struct scenariodata_ctc {
 	/*0x00*/ s16 playercountsperteam[4];
 	/*0x08*/ s16 teamindexes[4];
-	/*0x10*/ s16 baserooms[4];
+	/*0x10*/ RoomNum baserooms[4];
 	/*0x18*/ struct ctcspawnpadsperteam spawnpadsperteam[4];
 	/*0x58*/ struct prop *tokens[4];
 };
@@ -4589,8 +4590,8 @@ struct explosionpart {
 struct explosionbb {
 	struct coord bbmin;
 	struct coord bbmax;
-	s16 room;
-	s16 room2;
+	RoomNum room;
+	RoomNum room2;
 };
 
 struct explosion {
@@ -4598,7 +4599,7 @@ struct explosion {
 	struct prop *source; // Prop of the thing that created the explosion
 	struct explosionpart parts[40];
 	/*0x3c8*/ s16 age;
-	/*0x3ca*/ s16 room;
+	/*0x3ca*/ RoomNum room;
 	/*0x3cc*/ s8 type;
 	/*0x3cd*/ s8 makescorch;
 	/*0x3ce*/ s8 owner;
@@ -5134,7 +5135,7 @@ struct bgcmd {
 };
 
 struct drawslot {
-	s16 roomnum;
+	RoomNum roomnum;
 	u8 unk02;
 	u8 draworder;
 	struct screenbox box;
@@ -5151,8 +5152,8 @@ struct zrange {
 };
 
 struct bgsnakeitem {
-	/*0x00*/ s16 roomnum;
-	/*0x02*/ s16 fromroomnums[5];
+	/*0x00*/ RoomNum roomnum;
+	/*0x02*/ RoomNum fromroomnums[5];
 	/*0x0c*/ u8 depth;
 	/*0x0d*/ u8 numportals;
 	/*0x0e*/ s16 roomportallistoffset;
@@ -5594,7 +5595,7 @@ struct var80067e6c {
 };
 
 struct shard {
-	/*0x00*/ s16 room;
+	/*0x00*/ RoomNum room;
 	/*0x04*/ s32 age60;
 	/*0x08*/ struct coord pos;
 	/*0x14*/ struct coord rot;
@@ -5639,7 +5640,7 @@ struct pschannel {
 	/*0x50*/ struct prop *prop;
 	/*0x54*/ struct coord *posptr;
 	/*0x58*/ struct coord pos;
-	/*0x64*/ s16 rooms[8];
+	/*0x64*/ RoomNum rooms[8];
 #if VERSION >= VERSION_NTSC_1_0
 	/*0x74*/ u32 uuid;
 #endif
@@ -5677,7 +5678,7 @@ struct wallhit {
 	/*0x5c*/ struct prop *chrprop;
 	/*0x60*/ struct prop *objprop;
 	/*0x64*/ Vtx *vertices2; // overridden vertices for when blood is expanding
-	/*0x68*/ s16 roomnum;
+	/*0x68*/ RoomNum roomnum;
 	/*0x6a*/ u8 texturenum;
 	/*0x6b*/ u8 unk6b;
 	/*0x6c*/ u8 mtxindex;
diff --git a/src/lib/collision.c b/src/lib/collision.c
index eb75cb0e0..f9eab66e8 100644
--- a/src/lib/collision.c
+++ b/src/lib/collision.c
@@ -962,9 +962,9 @@ bool cd00026a04(struct coord *pos, u8 *start, u8 *end, u16 geoflags, s32 room, s
 	return result;
 }
 
-void cdFindClosestVertical(struct coord *pos, s16 *rooms, u16 geoflags, struct geo **geoptr, s16 *roomptr, f32 *groundptr, struct prop **propptr, bool ceiling)
+void cdFindClosestVertical(struct coord *pos, RoomNum *rooms, u16 geoflags, struct geo **geoptr, RoomNum *roomptr, f32 *groundptr, struct prop **propptr, bool ceiling)
 {
-	s16 *roomptr2;
+	RoomNum *roomptr2;
 	s32 roomnum;
 	u8 *start;
 	u8 *end;
@@ -1262,9 +1262,9 @@ void cdCollectGeoForCylFromList(struct coord *pos, f32 radius, u8 *start, u8 *en
 	}
 }
 
-void cdCollectGeoForCyl(struct coord *pos, f32 radius, s16 *rooms, u32 types, u16 geoflags, bool checkvertical, f32 ymax, f32 ymin, struct collision *collisions, s32 maxcollisions)
+void cdCollectGeoForCyl(struct coord *pos, f32 radius, RoomNum *rooms, u32 types, u16 geoflags, bool checkvertical, f32 ymax, f32 ymin, struct collision *collisions, s32 maxcollisions)
 {
-	s16 *roomptr;
+	RoomNum *roomptr;
 	s32 roomnum;
 	u8 *start;
 	u8 *end;
@@ -1590,9 +1590,9 @@ void cdCollectGeoForCylMoveFromList(u8 *start, u8 *end, struct coord *pos, f32 r
 	}
 }
 
-void cdCollectGeoForCylMove(struct coord *pos, f32 width, s16 *rooms, u32 types, u16 geoflags, bool checkvertical, f32 ymax, f32 ymin, struct collision *collisions, s32 maxcollisions)
+void cdCollectGeoForCylMove(struct coord *pos, f32 width, RoomNum *rooms, u32 types, u16 geoflags, bool checkvertical, f32 ymax, f32 ymin, struct collision *collisions, s32 maxcollisions)
 {
-	s16 *roomptr;
+	RoomNum *roomptr;
 	s32 roomnum;
 	u8 *start;
 	u8 *end;
@@ -2139,7 +2139,7 @@ f32 cdFindGroundFromList(struct collision *collisions, struct coord *pos, struct
  * There is nothing specific to ladders in this function, but it's only used
  * for finding ladders.
  */
-bool cdFindLadder(struct coord *pos, f32 width, f32 ymax, f32 ymin, s16 *rooms, u16 geoflags, struct coord *laddernormal)
+bool cdFindLadder(struct coord *pos, f32 width, f32 ymax, f32 ymin, RoomNum *rooms, u16 geoflags, struct coord *laddernormal)
 {
 	struct collision collisions[2];
 
@@ -2167,7 +2167,7 @@ bool cdFindLadder(struct coord *pos, f32 width, f32 ymax, f32 ymin, s16 *rooms,
 	return false;
 }
 
-bool cd0002a13c(struct coord *pos, f32 radius, f32 ymax, f32 ymin, s16 *rooms, u16 geoflags)
+bool cd0002a13c(struct coord *pos, f32 radius, f32 ymax, f32 ymin, RoomNum *rooms, u16 geoflags)
 {
 	struct collision collisions[2];
 
@@ -2180,8 +2180,8 @@ bool cd0002a13c(struct coord *pos, f32 radius, f32 ymax, f32 ymin, s16 *rooms, u
 	return false;
 }
 
-f32 cdFindGroundInfoAtCyl(struct coord *pos, f32 radius, s16 *rooms, u16 *floorcol,
-		u8 *floortype, u16 *floorflags, s16 *floorroom, s32 *inlift, struct prop **lift)
+f32 cdFindGroundInfoAtCyl(struct coord *pos, f32 radius, RoomNum *rooms, u16 *floorcol,
+		u8 *floortype, u16 *floorflags, RoomNum *floorroom, s32 *inlift, struct prop **lift)
 {
 	struct collision collisions[21];
 	struct collision *sp72 = NULL;
@@ -2244,15 +2244,15 @@ f32 cdReturnZero(void)
 	return 0;
 }
 
-f32 cdFindGroundAtCyl(struct coord *pos, f32 radius, s16 *rooms, u16 *floorcol, u8 *floortype)
+f32 cdFindGroundAtCyl(struct coord *pos, f32 radius, RoomNum *rooms, u16 *floorcol, u8 *floortype)
 {
 	return cdFindGroundInfoAtCyl(pos, radius, rooms, floorcol, floortype, NULL, NULL, NULL, NULL);
 }
 
-f32 cdFindFloorYColourTypeAtPos(struct coord *pos, s16 *rooms, u16 *floorcol, u8 *floortype)
+f32 cdFindFloorYColourTypeAtPos(struct coord *pos, RoomNum *rooms, u16 *floorcol, u8 *floortype)
 {
 	struct geo *geo;
-	s16 sp30[2];
+	RoomNum sp30[2];
 	f32 sp2c;
 	f32 result = -4294967296;
 
@@ -2273,10 +2273,10 @@ f32 cdFindFloorYColourTypeAtPos(struct coord *pos, s16 *rooms, u16 *floorcol, u8
 	return result;
 }
 
-s32 cdFindFloorRoomAtPos(struct coord *pos, s16 *nearrooms)
+s32 cdFindFloorRoomAtPos(struct coord *pos, RoomNum *nearrooms)
 {
 	struct geo *geo;
-	s16 room;
+	RoomNum room;
 	f32 sp2c;
 
 	cdFindClosestVertical(pos, nearrooms, GEOFLAG_FLOOR1 | GEOFLAG_FLOOR2, &geo, &room, &sp2c, 0, SURFACE_FLOOR);
@@ -2285,13 +2285,13 @@ s32 cdFindFloorRoomAtPos(struct coord *pos, s16 *nearrooms)
 }
 
 #if VERSION >= VERSION_NTSC_1_0
-s16 cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr)
+RoomNum cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr)
 #else
-s16 cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr)
+RoomNum cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr)
 #endif
 {
 	struct geo *geo;
-	s16 room;
+	RoomNum room;
 	f32 sp2c;
 
 	cdFindClosestVertical(pos, rooms, GEOFLAG_FLOOR1 | GEOFLAG_FLOOR2, &geo, &room, &sp2c, NULL, SURFACE_FLOOR);
@@ -2314,13 +2314,13 @@ s16 cdFindFloorRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u
 }
 
 #if VERSION >= VERSION_NTSC_1_0
-s16 cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr)
+RoomNum cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr, u16 *flagsptr)
 #else
-s16 cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcolptr)
+RoomNum cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcolptr)
 #endif
 {
 	struct geo *geo;
-	s16 sp32;
+	RoomNum sp32;
 	f32 sp2c;
 
 	cdFindClosestVertical(pos, rooms, GEOFLAG_FLOOR1 | GEOFLAG_FLOOR2, &geo, &sp32, &sp2c, NULL, SURFACE_CEILING);
@@ -2342,10 +2342,10 @@ s16 cdFindCeilingRoomYColourFlagsAtPos(struct coord *pos, s16 *rooms, f32 *arg2,
 	return sp32;
 }
 
-s16 cdFindFloorRoomYColourNormalPropAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcol, struct coord *normal, struct prop **propptr)
+RoomNum cdFindFloorRoomYColourNormalPropAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcol, struct coord *normal, struct prop **propptr)
 {
 	struct geo *geo;
-	s16 room;
+	RoomNum room;
 	f32 sp2c;
 
 	cdFindClosestVertical(pos, rooms, GEOFLAG_FLOOR1 | GEOFLAG_FLOOR2, &geo, &room, &sp2c, propptr, SURFACE_FLOOR);
@@ -2362,10 +2362,10 @@ s16 cdFindFloorRoomYColourNormalPropAtPos(struct coord *pos, s16 *rooms, f32 *ar
 	return room;
 }
 
-s16 cdFindCeilingRoomYColourFlagsNormalAtPos(struct coord *pos, s16 *rooms, f32 *arg2, u16 *floorcol, u16 *flagsptr, struct coord *normal)
+RoomNum cdFindCeilingRoomYColourFlagsNormalAtPos(struct coord *pos, RoomNum *rooms, f32 *arg2, u16 *floorcol, u16 *flagsptr, struct coord *normal)
 {
 	struct geo *geo;
-	s16 sp32;
+	RoomNum sp32;
 	f32 sp2c;
 
 	cdFindClosestVertical(pos, rooms, GEOFLAG_FLOOR1 | GEOFLAG_FLOOR2, &geo, &sp32, &sp2c, NULL, SURFACE_CEILING);
@@ -2389,7 +2389,7 @@ s16 cdFindCeilingRoomYColourFlagsNormalAtPos(struct coord *pos, s16 *rooms, f32
 /**
  * Tests if a cylinder volume fits in the given position.
  */
-s32 cdTestVolume(struct coord *pos, f32 width, s16 *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin)
+s32 cdTestVolume(struct coord *pos, f32 width, RoomNum *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin)
 {
 	struct collision collisions[2];
 	bool result = true;
@@ -2404,7 +2404,7 @@ s32 cdTestVolume(struct coord *pos, f32 width, s16 *rooms, s32 types, bool check
 	return result;
 }
 
-s32 cdExamCylMove01(struct coord *pos, struct coord *pos2, f32 radius, s16 *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin)
+s32 cdExamCylMove01(struct coord *pos, struct coord *pos2, f32 radius, RoomNum *rooms, s32 types, bool checkvertical, f32 ymax, f32 ymin)
 {
 	struct collision collisions[2];
 	s32 cdresult;
@@ -2469,7 +2469,7 @@ s32 cdExamCylMove01(struct coord *pos, struct coord *pos2, f32 radius, s16 *room
 	return cdresult;
 }
 
-s32 cdExamCylMove02(struct coord *origpos, struct coord *dstpos, f32 width, s16 *dstrooms, s32 types, bool checkvertical, f32 ymax, f32 ymin)
+s32 cdExamCylMove02(struct coord *origpos, struct coord *dstpos, f32 width, RoomNum *dstrooms, s32 types, bool checkvertical, f32 ymax, f32 ymin)
 {
 	struct collision collisions[21];
 	struct coord dist;
@@ -3337,10 +3337,10 @@ bool cdExamAToBGeolist(u8 *start, u8 *end, struct coord *arg2, struct coord *arg
 	return !result;
 }
 
-bool cdTestAToB(struct coord *pos, struct coord *coord2, s16 *rooms, u32 types, u16 geoflags, bool checkvertical, s32 arg6, f32 ymax, f32 ymin)
+bool cdTestAToB(struct coord *pos, struct coord *coord2, RoomNum *rooms, u32 types, u16 geoflags, bool checkvertical, s32 arg6, f32 ymax, f32 ymin)
 {
 	s32 roomnum;
-	s16 *roomptr;
+	RoomNum *roomptr;
 	u8 *start;
 	u8 *end;
 	struct coord sp27c;
@@ -3391,10 +3391,10 @@ bool cdTestAToB(struct coord *pos, struct coord *coord2, s16 *rooms, u32 types,
 	return true;
 }
 
-s32 cdExamAToB(struct coord *arg0, struct coord *arg1, s16 *rooms, s32 types, u16 geoflags, bool checkvertical, s32 arg6, f32 ymax, f32 ymin)
+s32 cdExamAToB(struct coord *arg0, struct coord *arg1, RoomNum *rooms, s32 types, u16 geoflags, bool checkvertical, s32 arg6, f32 ymax, f32 ymin)
 {
 	s32 roomnum;
-	s16 *roomptr;
+	RoomNum *roomptr;
 	u8 *start;
 	u8 *end;
 	struct coord sp2c4;
@@ -3451,21 +3451,21 @@ s32 cdExamAToB(struct coord *arg0, struct coord *arg1, s16 *rooms, s32 types, u1
 	return !sp2c0;
 }
 
-bool cdTestCylMove01(struct coord *pos, s16 *rooms, struct coord *targetpos, u32 types, u32 arg4, f32 ymax, f32 ymin)
+bool cdTestCylMove01(struct coord *pos, RoomNum *rooms, struct coord *targetpos, u32 types, u32 arg4, f32 ymax, f32 ymin)
 {
-	s16 sp44[21];
-	s16 sp34[8];
+	RoomNum sp44[21];
+	RoomNum sp34[8];
 
 	portal00018148(pos, targetpos, rooms, sp34, sp44, 20);
 
 	return cdTestAToB(pos, targetpos, sp44, types, GEOFLAG_WALL, CHECKVERTICAL_NO, arg4, ymax, ymin);
 }
 
-s32 cdTestCylMove02(struct coord *pos, s16 *rooms, struct coord *coord2, s16 *rooms2, u32 types, s32 arg5, f32 ymax, f32 ymin)
+s32 cdTestCylMove02(struct coord *pos, RoomNum *rooms, struct coord *coord2, RoomNum *rooms2, u32 types, s32 arg5, f32 ymax, f32 ymin)
 {
 	s32 result;
-	s16 sp44[20];
-	s16 sp34[8];
+	RoomNum sp44[20];
+	RoomNum sp34[8];
 
 	func0f065d1c(pos, rooms, coord2, sp34, sp44, 20);
 
@@ -3478,29 +3478,29 @@ s32 cdTestCylMove02(struct coord *pos, s16 *rooms, struct coord *coord2, s16 *ro
 	return result;
 }
 
-s32 cdExamCylMove03(struct coord *pos, s16 *rooms, struct coord *arg2, u32 types, u32 arg4, f32 ymax, f32 ymin)
+s32 cdExamCylMove03(struct coord *pos, RoomNum *rooms, struct coord *arg2, u32 types, u32 arg4, f32 ymax, f32 ymin)
 {
-	s16 sp44[21];
-	s16 sp34[8];
+	RoomNum sp44[21];
+	RoomNum sp34[8];
 
 	portal00018148(pos, arg2, rooms, sp34, sp44, 20);
 
 	return cdExamAToB(pos, arg2, sp44, types, GEOFLAG_WALL, CHECKVERTICAL_NO, arg4, ymax, ymin);
 }
 
-s32 cdTestCylMove04(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin)
+s32 cdTestCylMove04(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin)
 {
-	s16 rooms[21];
+	RoomNum rooms[21];
 
 	portal00018148(arg0, arg2, arg1, arg3, rooms, 20);
 
 	return cdTestAToB(arg0, arg2, rooms, types, GEOFLAG_WALL, CHECKVERTICAL_NO, arg5, ymax, ymin);
 }
 
-s32 cdExamCylMove05(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2, s32 types, bool arg5, f32 ymax, f32 ymin)
+s32 cdExamCylMove05(struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2, s32 types, bool arg5, f32 ymax, f32 ymin)
 {
-	s16 sp44[21];
-	s16 sp34[8];
+	RoomNum sp44[21];
+	RoomNum sp34[8];
 	s32 result;
 
 	func0f065d1c(pos, rooms, pos2, sp34, sp44, 20);
@@ -3515,10 +3515,10 @@ s32 cdExamCylMove05(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *room
 	return result;
 }
 
-s32 cdExamCylMove06(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, f32 width, s32 types, s32 arg6, f32 ymax, f32 ymin)
+s32 cdExamCylMove06(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, f32 width, s32 types, s32 arg6, f32 ymax, f32 ymin)
 {
-	s16 sp5c[21];
-	s16 sp4c[8];
+	RoomNum sp5c[21];
+	RoomNum sp4c[8];
 	struct coord sp40;
 	s32 result;
 
@@ -3540,18 +3540,18 @@ s32 cdExamCylMove06(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3
 	return result;
 }
 
-s32 cdExamCylMove07(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin)
+s32 cdExamCylMove07(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types, s32 arg5, f32 ymax, f32 ymin)
 {
-	s16 rooms[21];
+	RoomNum rooms[21];
 
 	portal00018148(arg0, arg2, arg1, arg3, rooms, 20);
 
 	return cdExamAToB(arg0, arg2, rooms, types, GEOFLAG_WALL, CHECKVERTICAL_NO, arg5, ymax, ymin);
 }
 
-s32 cdExamCylMove08(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, f32 width, u32 types, s32 arg6, f32 ymax, f32 ymin)
+s32 cdExamCylMove08(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, f32 width, u32 types, s32 arg6, f32 ymax, f32 ymin)
 {
-	s16 rooms[21];
+	RoomNum rooms[21];
 	struct coord sp40;
 	s32 result;
 
@@ -3570,26 +3570,26 @@ s32 cdExamCylMove08(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3
 	return result;
 }
 
-bool cdTestLos03(struct coord *viewpos, s16 *rooms, struct coord *targetpos, u32 types, u16 geoflags)
+bool cdTestLos03(struct coord *viewpos, RoomNum *rooms, struct coord *targetpos, u32 types, u16 geoflags)
 {
-	s16 sp44[21];
-	s16 sp34[8];
+	RoomNum sp44[21];
+	RoomNum sp34[8];
 
 	portal00018148(viewpos, targetpos, rooms, sp34, sp44, 20);
 
 	return cdTestAToB(viewpos, targetpos, sp44, types, geoflags, CHECKVERTICAL_YES, 1, 0, 0);
 }
 
-bool cdTestLos04(struct coord *frompos, s16 *fromrooms, struct coord *topos, s32 types)
+bool cdTestLos04(struct coord *frompos, RoomNum *fromrooms, struct coord *topos, s32 types)
 {
 	return cdTestLos03(frompos, fromrooms, topos, types, GEOFLAG_WALL | GEOFLAG_BLOCK_SIGHT | GEOFLAG_BLOCK_SHOOT);
 }
 
-bool cdTestLos05(struct coord *coord, s16 *rooms, struct coord *coord2, s16 *rooms2, s32 types, u16 geoflags)
+bool cdTestLos05(struct coord *coord, RoomNum *rooms, struct coord *coord2, RoomNum *rooms2, s32 types, u16 geoflags)
 {
 	bool result;
-	s16 sp44[20];
-	s16 sp34[8];
+	RoomNum sp44[20];
+	RoomNum sp34[8];
 
 	func0f065d1c(coord, rooms, coord2, sp34, sp44, 20);
 
@@ -3602,15 +3602,15 @@ bool cdTestLos05(struct coord *coord, s16 *rooms, struct coord *coord2, s16 *roo
 	return result;
 }
 
-bool cdTestLos06(struct coord *arg0, s16 *rooms1, struct coord *arg2, s16 *rooms2, u32 types)
+bool cdTestLos06(struct coord *arg0, RoomNum *rooms1, struct coord *arg2, RoomNum *rooms2, u32 types)
 {
 	return cdTestLos05(arg0, rooms1, arg2, rooms2, types, GEOFLAG_WALL | GEOFLAG_BLOCK_SIGHT | GEOFLAG_BLOCK_SHOOT);
 }
 
-bool cdTestLos07(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2, s16 *rooms3, u32 types, u16 geoflags)
+bool cdTestLos07(struct coord *pos, RoomNum *rooms, struct coord *pos2, RoomNum *rooms2, RoomNum *rooms3, u32 types, u16 geoflags)
 {
 	bool result;
-	s16 sp34[20];
+	RoomNum sp34[20];
 
 	func0f065d1c(pos, rooms, pos2, rooms3, sp34, 20);
 
@@ -3623,31 +3623,31 @@ bool cdTestLos07(struct coord *pos, s16 *rooms, struct coord *pos2, s16 *rooms2,
 	return result;
 }
 
-s32 cdExamLos08(struct coord *pos, s16 *rooms, struct coord *pos2, u32 types, u16 geoflags)
+s32 cdExamLos08(struct coord *pos, RoomNum *rooms, struct coord *pos2, u32 types, u16 geoflags)
 {
-	s16 sp44[21];
-	s16 sp34[8];
+	RoomNum sp44[21];
+	RoomNum sp34[8];
 
 	portal00018148(pos, pos2, rooms, sp34, sp44, 20);
 
 	return cdExamAToB(pos, pos2, sp44, types, geoflags, CHECKVERTICAL_YES, 1, 0, 0);
 }
 
-s32 cdExamLos09(struct coord *pos, s16 *rooms, struct coord *pos2, u32 types)
+s32 cdExamLos09(struct coord *pos, RoomNum *rooms, struct coord *pos2, u32 types)
 {
 	return cdExamLos08(pos, rooms, pos2, types, GEOFLAG_WALL | GEOFLAG_BLOCK_SIGHT | GEOFLAG_BLOCK_SHOOT);
 }
 
-s32 cdTestLos10(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types, u16 geoflags)
+s32 cdTestLos10(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types, u16 geoflags)
 {
-	s16 rooms[21];
+	RoomNum rooms[21];
 
 	portal00018148(arg0, arg2, arg1, arg3, rooms, 20);
 
 	return cdTestAToB(arg0, arg2, rooms, types, geoflags, CHECKVERTICAL_YES, 1, 0, 0);
 }
 
-s32 cdTestLos11(struct coord *arg0, s16 *arg1, struct coord *arg2, s16 *arg3, u32 types)
+s32 cdTestLos11(struct coord *arg0, RoomNum *arg1, struct coord *arg2, RoomNum *arg3, u32 types)
 {
 	return cdTestLos10(arg0, arg1, arg2, arg3, types, GEOFLAG_WALL | GEOFLAG_BLOCK_SIGHT | GEOFLAG_BLOCK_SHOOT);
 }
@@ -3811,13 +3811,13 @@ s32 cdTestBlockOverlapsGeolist(u8 *start, u8 *end, struct geoblock *block, u16 g
  * and is also used in a sanity check to make sure a moved object hasn't moved
  * into the player's position.
  */
-s32 cdTestBlockOverlapsAnyProp(struct geoblock *geo, s16 *rooms, u32 types)
+s32 cdTestBlockOverlapsAnyProp(struct geoblock *geo, RoomNum *rooms, u32 types)
 {
 	s32 result = CDRESULT_NOCOLLISION;
 	s32 roomnum;
 	u8 *start;
 	u8 *end;
-	s16 *roomptr;
+	RoomNum *roomptr;
 	s16 propnums[256];
 	s16 *propnumptr;
 
@@ -4065,7 +4065,7 @@ bool cd0002ed30(u8 *start, u8 *end, struct geoblock *block, s32 numvertices, str
 	return true;
 }
 
-bool cd0002f02c(struct geoblock *block, s16 *rooms, s32 types)
+bool cd0002f02c(struct geoblock *block, RoomNum *rooms, s32 types)
 {
 	s32 numvertices = block->header.numvertices;
 	s32 i;
@@ -4093,7 +4093,7 @@ bool cd0002f02c(struct geoblock *block, s16 *rooms, s32 types)
 	}
 
 	if (types & CDTYPE_BG) {
-		s16 *roomsptr = rooms;
+		RoomNum *roomsptr = rooms;
 		s32 roomnum = *roomsptr;
 
 		while (roomnum != -1) {
@@ -4232,7 +4232,7 @@ void cd0002f2fc(u32 arg0, u32 arg1)
 	// empty
 }
 
-bool cdIsNearlyInSightWithFlags(struct coord *viewpos, s16 *rooms, struct coord *targetpos, f32 distance, s32 types, u16 geoflags)
+bool cdIsNearlyInSightWithFlags(struct coord *viewpos, RoomNum *rooms, struct coord *targetpos, f32 distance, s32 types, u16 geoflags)
 {
 	struct coord diff;
 	f32 x;
@@ -4271,7 +4271,7 @@ bool cdIsNearlyInSightWithFlags(struct coord *viewpos, s16 *rooms, struct coord
 	return false;
 }
 
-bool cdIsNearlyInSight(struct coord *viewpos, s16 *rooms, struct coord *targetpos, f32 distance, s32 types)
+bool cdIsNearlyInSight(struct coord *viewpos, RoomNum *rooms, struct coord *targetpos, f32 distance, s32 types)
 {
 	return cdIsNearlyInSightWithFlags(viewpos, rooms, targetpos, distance, types, GEOFLAG_BLOCK_SIGHT);
 }
diff --git a/src/lib/lib_17ce0.c b/src/lib/lib_17ce0.c
index 071dd02d9..e319ec44f 100644
--- a/src/lib/lib_17ce0.c
+++ b/src/lib/lib_17ce0.c
@@ -59,7 +59,7 @@ void portal00018e74nb(s32 portalnum)
  * The list is assumed to have 16 slots, with the last being reserved for the
  * -1 terminator.
  */
-void portal00017dc4(s16 *rooms, s16 roomnum)
+void portal00017dc4(RoomNum *rooms, RoomNum roomnum)
 {
 	s32 i;
 
@@ -169,16 +169,16 @@ s32 portalCalculateIntersection(s32 portalnum, struct coord *pos1, struct coord
 		: PORTALINTERSECTION_FRONTTOBEHIND;
 }
 
-void portal00018148(struct coord *pos1, struct coord *pos2, s16 *rooms1, s16 *rooms2, s16 *rooms3, s32 arg5)
+void portal00018148(struct coord *pos1, struct coord *pos2, RoomNum *rooms1, RoomNum *rooms2, RoomNum *rooms3, s32 arg5)
 {
 	s32 i;
 	s32 j;
 	s32 roomnum;
 	s32 numportals;
 	s16 *portalnums;
-	s16 rooms9c[16];
-	s16 rooms7c[16];
-	s16 rooms5c[16];
+	RoomNum rooms9c[16];
+	RoomNum rooms7c[16];
+	RoomNum rooms5c[16];
 
 	for (i = 0; i < 8; i++) {
 		rooms9c[i] = rooms1[i];