diff --git a/src/c_cmds.c b/src/c_cmds.c
index b86cc4aa85..c35dc3aaaf 100644
--- a/src/c_cmds.c
+++ b/src/c_cmds.c
@@ -4020,7 +4020,7 @@ static bool map_cmd_func1(char *cmd, char *parms)
                 M_StringCopy(wadname, leafname(lumpinfo[i]->wadfile->path), sizeof(wadname));
                 replaced = (W_CheckMultipleLumps(mapcmdlump) > 1 && !chex && !FREEDOOM);
                 pwad = (lumpinfo[i]->wadfile->type == PWAD);
-                M_StringCopy(mapinfoname, P_GetMapName((mapcmdepisode - 1) * 10 + mapcmdmap), sizeof(mapinfoname));
+                M_StringCopy(mapinfoname, P_GetMapName(mapcmdepisode, mapcmdmap), sizeof(mapinfoname));
 
                 switch (gamemission)
                 {
@@ -4237,7 +4237,7 @@ static void maplist_cmd_func2(char *cmd, char *parms)
         M_StringCopy(wadname, leafname(lumpinfo[i]->wadfile->path), sizeof(wadname));
         replaced = (W_CheckMultipleLumps(lump) > 1 && !chex && !FREEDOOM);
         pwad = (lumpinfo[i]->wadfile->type == PWAD);
-        M_StringCopy(mapinfoname, P_GetMapName(--ep * 10 + (--map) + 1), sizeof(mapinfoname));
+        M_StringCopy(mapinfoname, P_GetMapName(--ep, --map), sizeof(mapinfoname));
 
         switch (gamemission)
         {
@@ -4591,13 +4591,12 @@ static void mapstats_cmd_func2(char *cmd, char *parms)
             /* 59 */ { JR,    "",   "",    "",   "" }
         };
 
-        const int   i = (gamemission == doom ? gameepisode * 10 : 0) + gamemap;
-        const char  *author = P_GetMapAuthor(i);
+        const char  *author = P_GetMapAuthor(gameepisode, gamemap);
 
         if (*author)
             C_TabbedOutput(tabs, "Author\t%s", author);
-        else if (canmodify && *authors[i][gamemission])
-            C_TabbedOutput(tabs, "Author\t%s", authors[i][gamemission]);
+        else if (canmodify && *authors[gameepisode][gamemission])
+            C_TabbedOutput(tabs, "Author\t%s", authors[gameepisode][gamemission]);
         else if (REKKR)
             C_TabbedOutput(tabs, "Author\tMatthew Little");
     }
@@ -4859,8 +4858,8 @@ static void mapstats_cmd_func2(char *cmd, char *parms)
     {
         int                 lumps;
         char                namebuf[9];
-        const char          *musicartist = P_GetMapMusicComposer((gameepisode - 1) * 10 + gamemap);
-        const char          *musictitle = P_GetMapMusicTitle((gameepisode - 1) * 10 + gamemap);
+        const char          *musicartist = P_GetMapMusicComposer(gameepisode, gamemap);
+        const char          *musictitle = P_GetMapMusicTitle(gameepisode, gamemap);
         const Mix_MusicType musictype = Mix_GetMusicType(NULL);
 
         temp = uppercase(mus_playing->name1);
diff --git a/src/f_finale.c b/src/f_finale.c
index 5cff11630c..6cc21e4bb1 100644
--- a/src/f_finale.c
+++ b/src/f_finale.c
@@ -107,8 +107,8 @@ static void F_ConsoleFinaleText(void)
 //
 void F_StartFinale(void)
 {
-    char    *intertext = P_GetInterText(gamemap);
-    char    *intersecret = P_GetInterSecretText(gamemap);
+    char    *intertext = P_GetInterText(gameepisode, gamemap);
+    char    *intersecret = P_GetInterSecretText(gameepisode, gamemap);
 
     viewactive = false;
     automapactive = false;
@@ -121,8 +121,8 @@ void F_StartFinale(void)
 
     if (*intertext || (*intersecret && secretexit))
     {
-        char    *interbackdrop = P_GetInterBackrop(gamemap);
-        int     mus = P_GetInterMusic(gamemap);
+        char    *interbackdrop = P_GetInterBackrop(gameepisode, gamemap);
+        int     mus = P_GetInterMusic(gameepisode, gamemap);
 
         if (!secretexit)
         {
@@ -152,7 +152,7 @@ void F_StartFinale(void)
         else
             S_ChangeMusic((gamemode == commercial ? mus_read_m : mus_victor), true, false, false);
     }
-    else if (P_GetMapEndCast(gamemap))
+    else if (P_GetMapEndCast(gameepisode, gamemap))
     {
         gameaction = ga_nothing;
         gamestate = GS_FINALE;
@@ -307,16 +307,16 @@ void F_Ticker(void)
         if (finalecount > FixedMul((fixed_t)strlen(finaletext) * FRACUNIT, TextSpeed()) + (midstage ? NEWTEXTWAIT : TEXTWAIT)
             || (midstage && acceleratestage))
         {
-            if (P_GetMapEndCast(gamemap))
+            if (P_GetMapEndCast(gameepisode, gamemap))
                 F_StartCast();
-            else if (P_GetMapEndBunny(gamemap))
+            else if (P_GetMapEndBunny(gameepisode, gamemap))
             {
                 finalecount = 0;
                 finalestage = F_STAGE_ARTSCREEN;
                 wipegamestate = GS_NONE;
                 S_StartMusic(mus_bunny);
             }
-            else if (P_GetMapEndGame(gamemap))
+            else if (P_GetMapEndGame(gameepisode, gamemap))
             {
                 finalecount = 0;
                 finalestage = F_STAGE_ARTSCREEN;
@@ -988,7 +988,7 @@ static void F_BunnyScroll(void)
 //
 static void F_ArtScreenDrawer(void)
 {
-    const int   lumpnum = P_GetMapEndPic(gamemap);
+    const int   lumpnum = P_GetMapEndPic(gameepisode, gamemap);
 
     if (lumpnum > 0)
     {
@@ -997,7 +997,7 @@ static void F_ArtScreenDrawer(void)
         else
             V_DrawPatch(0, 0, 0, W_CacheLumpNum(lumpnum));
     }
-    else if (P_GetMapEndBunny(gamemap) || gameepisode == 3)
+    else if (P_GetMapEndBunny(gameepisode, gamemap) || gameepisode == 3)
         F_BunnyScroll();
     else
     {
diff --git a/src/g_game.c b/src/g_game.c
index 8048485b24..20ffc889da 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -579,9 +579,8 @@ static void G_ResetPlayer(void)
 //
 void G_DoLoadLevel(void)
 {
-    int         ep;
-    const int   map = (gameepisode - 1) * 10 + gamemap;
-    bool        resetplayer;
+    int     ep;
+    bool    resetplayer;
 
     HU_DrawDisk();
 
@@ -622,8 +621,10 @@ void G_DoLoadLevel(void)
 
     freeze = false;
 
+    ep = (gamemode == commercial ? (gamemission == pack_nerve ? 2 : 1) : gameepisode);
+
     // [BH] Reset player's health, armor, weapons and ammo on pistol start
-    if ((resetplayer = (pistolstart || P_GetMapPistolStart(map))))
+    if ((resetplayer = (pistolstart || P_GetMapPistolStart(ep, gamemap))))
         G_ResetPlayer();
 
     if (viewplayer->cheats & CF_CHOPPERS)
@@ -653,13 +654,12 @@ void G_DoLoadLevel(void)
     // died.
     P_FreeSecNodeList();
 
-    ep = (gamemode == commercial ? (gamemission == pack_nerve ? 2 : 1) : gameepisode);
     P_MapName(ep, gamemap);
 
     P_SetupLevel(ep, gamemap);
 
     // [BH] Reset player's health, armor, weapons and ammo on pistol start
-    if (resetplayer && map != 1)
+    if (resetplayer && gamemap != 1)
     {
         if (M_StringCompare(playername, playername_default))
             C_Warning(0, "You now have 100%% health, no armor, and only a pistol with 50 bullets.");
@@ -1253,7 +1253,7 @@ void G_SecretExitLevel(void)
 
 int G_GetParTime(void)
 {
-    const int   par = P_GetMapPar((gameepisode - 1) * 10 + gamemap);
+    const int   par = P_GetMapPar(gameepisode, gamemap);
 
     if (par)
         return par;
@@ -1278,9 +1278,8 @@ int G_GetParTime(void)
 
 static void G_DoCompleted(void)
 {
-    const int   map = (gameepisode - 1) * 10 + gamemap;
-    const int   nextmap = P_GetMapNext(map);
-    const int   secretnextmap = P_GetMapSecretNext(map);
+    const int   nextmap = P_GetMapNext(gameepisode, gamemap);
+    const int   secretnextmap = P_GetMapSecretNext(gameepisode, gamemap);
 
     P_LookForFriends();
 
@@ -1448,8 +1447,8 @@ static void G_DoCompleted(void)
 //
 void G_WorldDone(void)
 {
-    const char  *intertext = P_GetInterText(gamemap);
-    const char  *intersecrettext = P_GetInterSecretText(gamemap);
+    const char  *intertext = P_GetInterText(gameepisode, gamemap);
+    const char  *intersecrettext = P_GetInterSecretText(gameepisode, gamemap);
 
     gameaction = ga_worlddone;
 
@@ -1462,7 +1461,7 @@ void G_WorldDone(void)
         return;
     }
 
-    if (P_GetMapEndCast(gamemap))
+    if (P_GetMapEndCast(gameepisode, gamemap))
     {
         F_StartFinale();
         return;
diff --git a/src/p_enemy.c b/src/p_enemy.c
index 792d0d8bbe..496bf60269 100644
--- a/src/p_enemy.c
+++ b/src/p_enemy.c
@@ -1958,9 +1958,8 @@ void A_Explode(mobj_t *actor, player_t *player, pspdef_t *psp)
 //
 void A_BossDeath(mobj_t *actor, player_t *player, pspdef_t *psp)
 {
-    line_t      junk = { 0 };
-    const int   map = (gameepisode - 1) * 10 + gamemap;
-    int         numbossactions = P_GetNumBossActions(map);
+    line_t  junk = { 0 };
+    int     numbossactions = P_GetNumBossActions(gameepisode, gamemap);
 
     // numbossactions == 0 means to use the defaults.
     // numbossactions == -1 means to do nothing.
@@ -1976,7 +1975,7 @@ void A_BossDeath(mobj_t *actor, player_t *player, pspdef_t *psp)
             return;         // no one left alive, so do not end game
 
         for (i = 0; i < numbossactions; i++)
-            if (P_GetBossAction(map, i)->type == actor->type)
+            if (P_GetBossAction(gameepisode, gamemap, i)->type == actor->type)
                 break;
 
         if (i >= numbossactions)
@@ -1994,7 +1993,7 @@ void A_BossDeath(mobj_t *actor, player_t *player, pspdef_t *psp)
 
         for (i = 0; i < numbossactions; i++)
         {
-            bossaction_t    *bossaction = P_GetBossAction(map, i);
+            bossaction_t    *bossaction = P_GetBossAction(gameepisode, gamemap, i);
 
             if (bossaction->type == actor->type)
             {
diff --git a/src/p_map.c b/src/p_map.c
index d890f8db5b..500b613e70 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -219,7 +219,7 @@ bool P_TeleportMove(mobj_t *thing, const fixed_t x, const fixed_t y, const fixed
     const sector_t  *newsec;
     const fixed_t   radius = thing->radius;
 
-    telefrag = (thing->player || boss || P_GetAllowMonsterTelefrags((gameepisode - 1) * 10 + gamemap));
+    telefrag = (thing->player || boss || P_GetAllowMonsterTelefrags(gameepisode, gamemap));
 
     // kill anything occupying the position
     tmthing = thing;
diff --git a/src/p_setup.c b/src/p_setup.c
index 0f109c95ee..aa5295608b 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -239,7 +239,7 @@ bool                skipblstart;            // MaxW: Skip initial blocklist shor
 static int          rejectlump = -1;        // cph - store reject lump num if cached
 const byte          *rejectmatrix;          // cph - const*
 
-static mapinfo_t    mapinfo[MAXMAPINFO];
+static mapinfo_t    mapinfo[10][100];
 
 static char *mapcmdnames[] =
 {
@@ -2855,7 +2855,7 @@ char    automaptitle[512];
 void P_MapName(int ep, int map)
 {
     bool        mapnumonly = false;
-    const char  *mapinfoname = trimwhitespace(P_GetMapName((ep - 1) * 10 + map));
+    const char  *mapinfoname = trimwhitespace(P_GetMapName(ep, map));
 
     switch (gamemission)
     {
@@ -3264,10 +3264,8 @@ void P_SetupLevel(int ep, int map)
 
     massacre = false;
 
-    map = (ep - 1) * 10 + map;
-
-    P_GetMapLiquids(map);
-    P_GetMapNoLiquids(map);
+    P_GetMapLiquids(ep, map);
+    P_GetMapNoLiquids(ep, map);
     P_SetLiquids();
 
     P_LoadThings(map, lumpnum + ML_THINGS);
@@ -3293,15 +3291,15 @@ void P_SetupLevel(int ep, int map)
     if (gamemode != shareware)
         S_ParseMusInfo(lumpname);
 
-    compat_corpsegibs = (compat_corpsegibs_global != -1 ? compat_corpsegibs_global : mapinfo[map].compat_corpsegibs);
-    compat_floormove = (compat_floormove_global != -1 ? compat_floormove_global : mapinfo[map].compat_floormove);
-    compat_light = (compat_light_global != -1 ? compat_light_global : mapinfo[map].compat_light);
-    compat_limitpain = (compat_limitpain_global != -1 ? compat_limitpain_global : mapinfo[map].compat_limitpain);
-    compat_nopassover = (compat_nopassover_global != -1 ? compat_nopassover_global : mapinfo[map].compat_nopassover);
-    compat_stairs = (compat_stairs_global != -1 ? compat_stairs_global : mapinfo[map].compat_stairs);
-    compat_useblocking = (compat_useblocking_global != -1 ? compat_useblocking_global : mapinfo[map].compat_useblocking);
-    compat_zombie = (compat_zombie_global != -1 ? compat_zombie_global : mapinfo[map].compat_zombie);
-    nograduallighting = (nograduallighting_global != -1 ? nograduallighting_global : mapinfo[map].nograduallighting);
+    compat_corpsegibs = (compat_corpsegibs_global != -1 ? compat_corpsegibs_global : mapinfo[ep][map].compat_corpsegibs);
+    compat_floormove = (compat_floormove_global != -1 ? compat_floormove_global : mapinfo[ep][map].compat_floormove);
+    compat_light = (compat_light_global != -1 ? compat_light_global : mapinfo[ep][map].compat_light);
+    compat_limitpain = (compat_limitpain_global != -1 ? compat_limitpain_global : mapinfo[ep][map].compat_limitpain);
+    compat_nopassover = (compat_nopassover_global != -1 ? compat_nopassover_global : mapinfo[ep][map].compat_nopassover);
+    compat_stairs = (compat_stairs_global != -1 ? compat_stairs_global : mapinfo[ep][map].compat_stairs);
+    compat_useblocking = (compat_useblocking_global != -1 ? compat_useblocking_global : mapinfo[ep][map].compat_useblocking);
+    compat_zombie = (compat_zombie_global != -1 ? compat_zombie_global : mapinfo[ep][map].compat_zombie);
+    nograduallighting = (nograduallighting_global != -1 ? nograduallighting_global : mapinfo[ep][map].nograduallighting);
 }
 
 static int  liquidlumps;
@@ -3309,41 +3307,42 @@ static int  noliquidlumps;
 
 static void P_InitMapInfo(void)
 {
-    for (int i = 0; i < MAXMAPINFO; i++)
-    {
-        mapinfo[i].author[0] = '\0';
-        mapinfo[i].endbunny = false;
-        mapinfo[i].endcast = false;
-        mapinfo[i].endgame = false;
-        mapinfo[i].endpic = 0;
-        mapinfo[i].enterpic = 0;
-        mapinfo[i].exitpic = 0;
-        mapinfo[i].cluster = 0;
-        mapinfo[i].interbackdrop[0] = '\0';
-        mapinfo[i].intermusic = 0;
-        mapinfo[i].intertext[0] = '\0';
-        mapinfo[i].intertextsecret[0] = '\0';
-
-        for (int j = 0; j < NUMLIQUIDS; j++)
+    for (int i = 0; i < 10; i++)
+        for (int j = 0; j < 100; j++)
         {
-            mapinfo[i].liquid[j] = -1;
-            mapinfo[i].noliquid[j] = -1;
-        }
+            mapinfo[i][j].author[0] = '\0';
+            mapinfo[i][j].endbunny = false;
+            mapinfo[i][j].endcast = false;
+            mapinfo[i][j].endgame = false;
+            mapinfo[i][j].endpic = 0;
+            mapinfo[i][j].enterpic = 0;
+            mapinfo[i][j].exitpic = 0;
+            mapinfo[i][j].cluster = 0;
+            mapinfo[i][j].interbackdrop[0] = '\0';
+            mapinfo[i][j].intermusic = 0;
+            mapinfo[i][j].intertext[0] = '\0';
+            mapinfo[i][j].intertextsecret[0] = '\0';
+
+            for (int k = 0; k < NUMLIQUIDS; k++)
+            {
+                mapinfo[i][j].liquid[k] = -1;
+                mapinfo[i][j].noliquid[k] = -1;
+            }
 
-        mapinfo[i].music = 0;
-        mapinfo[i].musicartist[0] = '\0';
-        mapinfo[i].musictitle[0] = '\0';
-        mapinfo[i].name[0] = '\0';
-        mapinfo[i].next = 0;
-        mapinfo[i].nojump = false;
-        mapinfo[i].nomouselook = false;
-        mapinfo[i].par = 0;
-        mapinfo[i].pistolstart = false;
-        mapinfo[i].secretnext = 0;
-        mapinfo[i].sky1texture = 0;
-        mapinfo[i].sky1scrolldelta = 0;
-        mapinfo[i].titlepatch = 0;
-    }
+            mapinfo[i][j].music = 0;
+            mapinfo[i][j].musicartist[0] = '\0';
+            mapinfo[i][j].musictitle[0] = '\0';
+            mapinfo[i][j].name[0] = '\0';
+            mapinfo[i][j].next = 0;
+            mapinfo[i][j].nojump = false;
+            mapinfo[i][j].nomouselook = false;
+            mapinfo[i][j].par = 0;
+            mapinfo[i][j].pistolstart = false;
+            mapinfo[i][j].secretnext = 0;
+            mapinfo[i][j].sky1texture = 0;
+            mapinfo[i][j].sky1scrolldelta = 0;
+            mapinfo[i][j].titlepatch = 0;
+        }
 }
 
 static void P_ParseMapString(const char *string, int *map, int *ep)
@@ -3514,7 +3513,7 @@ static bool P_ParseMapInfo(const char *scriptname)
                 }
             }
 
-            info = &mapinfo[map];
+            info = &mapinfo[ep][map];
 
             if (SC_GetString() && !SC_Compare("LOOKUP"))
                 M_StringCopy(info->name, sc_String, sizeof(info->name));
@@ -4058,143 +4057,143 @@ static bool P_ParseMapInfo(const char *scriptname)
     return true;
 }
 
-char *P_GetMapAuthor(const int map)
+char *P_GetMapAuthor(const int ep, const int map)
 {
-    return (MAPINFO >= 0 && mapinfo[map].author[0] ? mapinfo[map].author : (((E1M4B || *speciallumpname) && map == 4)
+    return (MAPINFO >= 0 && mapinfo[ep][map].author[0] ? mapinfo[ep][map].author : (((E1M4B || *speciallumpname) && map == 4)
         || ((E1M8B || *speciallumpname) && map == 8) || (onehumanity && map == 1) ? s_AUTHOR_ROMERO : ""));
 }
 
-int P_GetNumBossActions(const int map)
+int P_GetNumBossActions(const int ep, const int map)
 {
-    return mapinfo[map].numbossactions;
+    return mapinfo[ep][map].numbossactions;
 }
 
-bossaction_t *P_GetBossAction(const int map, const int i)
+bossaction_t *P_GetBossAction(const int ep, const int map, const int i)
 {
-    return &mapinfo[map].bossactions[i];
+    return &mapinfo[ep][map].bossactions[i];
 }
 
-char *P_GetInterBackrop(const int map)
+char *P_GetInterBackrop(const int ep, const int map)
 {
-    return mapinfo[map].interbackdrop;
+    return mapinfo[ep][map].interbackdrop;
 }
 
-int P_GetInterMusic(const int map)
+int P_GetInterMusic(const int ep, const int map)
 {
-    return mapinfo[map].intermusic;
+    return mapinfo[ep][map].intermusic;
 }
 
-char *P_GetInterText(const int map)
+char *P_GetInterText(const int ep, const int map)
 {
-    return mapinfo[map].intertext;
+    return mapinfo[ep][map].intertext;
 }
 
-char *P_GetInterSecretText(const int map)
+char *P_GetInterSecretText(const int ep, const int map)
 {
-    return mapinfo[map].intertextsecret;
+    return mapinfo[ep][map].intertextsecret;
 }
 
-bool P_GetMapEndBunny(const int map)
+bool P_GetMapEndBunny(const int ep, const int map)
 {
-    return mapinfo[map].endbunny;
+    return mapinfo[ep][map].endbunny;
 }
 
-bool P_GetMapEndCast(const int map)
+bool P_GetMapEndCast(const int ep, const int map)
 {
-    return mapinfo[map].endcast;
+    return mapinfo[ep][map].endcast;
 }
 
-bool P_GetMapEndGame(const int map)
+bool P_GetMapEndGame(const int ep, const int map)
 {
-    return mapinfo[map].endgame;
+    return mapinfo[ep][map].endgame;
 }
 
-int P_GetMapEndPic(const int map)
+int P_GetMapEndPic(const int ep, const int map)
 {
-    return mapinfo[map].endpic;
+    return mapinfo[ep][map].endpic;
 }
 
-int P_GetMapEnterPic(const int map)
+int P_GetMapEnterPic(const int ep, const int map)
 {
-    return mapinfo[map].enterpic;
+    return mapinfo[ep][map].enterpic;
 }
 
-int P_GetMapExitPic(const int map)
+int P_GetMapExitPic(const int ep, const int map)
 {
-    return mapinfo[map].exitpic;
+    return mapinfo[ep][map].exitpic;
 }
 
-void P_GetMapLiquids(const int map)
+void P_GetMapLiquids(const int ep, const int map)
 {
     for (int i = 0; i < liquidlumps; i++)
-        terraintypes[mapinfo[map].liquid[i]] = LIQUID;
+        terraintypes[mapinfo[ep][map].liquid[i]] = LIQUID;
 }
 
-int P_GetMapMusic(const int map)
+int P_GetMapMusic(const int ep, const int map)
 {
-    return mapinfo[map].music;
+    return mapinfo[ep][map].music;
 }
 
-char *P_GetMapMusicComposer(const int map)
+char *P_GetMapMusicComposer(const int ep, const int map)
 {
-    return mapinfo[map].musicartist;
+    return mapinfo[ep][map].musicartist;
 }
 
-char *P_GetMapMusicTitle(const int map)
+char *P_GetMapMusicTitle(const int ep, const int map)
 {
-    return mapinfo[map].musictitle;
+    return mapinfo[ep][map].musictitle;
 }
 
-char *P_GetMapName(const int map)
+char *P_GetMapName(const int ep, const int map)
 {
-    return (MAPINFO >= 0 && !sigil ? mapinfo[map].name : ((E1M4B || *speciallumpname) && map == 4 ? s_HUSTR_E1M4B :
+    return (MAPINFO >= 0 && !sigil ? mapinfo[ep][map].name : ((E1M4B || *speciallumpname) && map == 4 ? s_HUSTR_E1M4B :
         ((E1M8B || *speciallumpname) && map == 8 ? s_HUSTR_E1M8B : "")));
 }
 
-int P_GetMapNext(const int map)
+int P_GetMapNext(const int ep, const int map)
 {
-    return mapinfo[map].next;
+    return mapinfo[ep][map].next;
 }
 
-void P_GetMapNoLiquids(const int map)
+void P_GetMapNoLiquids(const int ep, const int map)
 {
     for (int i = 0; i < noliquidlumps; i++)
-        terraintypes[mapinfo[map].noliquid[i]] = SOLID;
+        terraintypes[mapinfo[ep][map].noliquid[i]] = SOLID;
 }
 
-int P_GetMapPar(const int map)
+int P_GetMapPar(const int ep, const int map)
 {
-    return mapinfo[map].par;
+    return mapinfo[ep][map].par;
 }
 
-bool P_GetMapPistolStart(const int map)
+bool P_GetMapPistolStart(const int ep, const int map)
 {
-    return mapinfo[map].pistolstart;
+    return mapinfo[ep][map].pistolstart;
 }
 
-int P_GetMapSecretNext(const int map)
+int P_GetMapSecretNext(const int ep, const int map)
 {
-    return mapinfo[map].secretnext;
+    return mapinfo[ep][map].secretnext;
 }
 
-int P_GetMapSky1Texture(const int map)
+int P_GetMapSky1Texture(const int ep, const int map)
 {
-    return mapinfo[map].sky1texture;
+    return mapinfo[ep][map].sky1texture;
 }
 
-int P_GetMapSky1ScrollDelta(const int map)
+int P_GetMapSky1ScrollDelta(const int ep, const int map)
 {
-    return mapinfo[map].sky1scrolldelta;
+    return mapinfo[ep][map].sky1scrolldelta;
 }
 
-int P_GetMapTitlePatch(const int map)
+int P_GetMapTitlePatch(const int ep, const int map)
 {
-    return mapinfo[map].titlepatch;
+    return mapinfo[ep][map].titlepatch;
 }
 
-int P_GetAllowMonsterTelefrags(int map)
+int P_GetAllowMonsterTelefrags(const int ep, const int map)
 {
-    return mapinfo[map].allowmonstertelefrags;
+    return mapinfo[ep][map].allowmonstertelefrags;
 }
 
 //
diff --git a/src/p_setup.h b/src/p_setup.h
index 6b8a8f9c64..f1000218fe 100644
--- a/src/p_setup.h
+++ b/src/p_setup.h
@@ -71,30 +71,30 @@ void P_MapName(int ep, int map);
 // Called by startup code.
 void P_Init(void);
 
-char *P_GetMapAuthor(const int map);
-int P_GetNumBossActions(const int map);
-bossaction_t *P_GetBossAction(const int map, const int i);
-char *P_GetInterBackrop(const int map);
-int P_GetInterMusic(const int map);
-char *P_GetInterText(const int map);
-char *P_GetInterSecretText(const int map);
-bool P_GetMapEndBunny(const int map);
-bool P_GetMapEndCast(const int map);
-bool P_GetMapEndGame(const int map);
-int P_GetMapEndPic(const int map);
-int P_GetMapEnterPic(const int map);
-int P_GetMapExitPic(const int map);
-void P_GetMapLiquids(const int map);
-int P_GetMapMusic(const int map);
-char *P_GetMapMusicComposer(const int map);
-char *P_GetMapMusicTitle(const int map);
-char *P_GetMapName(const int map);
-int P_GetMapNext(const int map);
-void P_GetMapNoLiquids(const int map);
-int P_GetMapPar(const int map);
-bool P_GetMapPistolStart(const int map);
-int P_GetMapSecretNext(const int map);
-int P_GetMapSky1Texture(const int map);
-int P_GetMapSky1ScrollDelta(const int map);
-int P_GetMapTitlePatch(const int map);
-int P_GetAllowMonsterTelefrags(int map);
+char *P_GetMapAuthor(const int ep, const int map);
+int P_GetNumBossActions(const int ep, const int map);
+bossaction_t *P_GetBossAction(const int ep, const int map, const int i);
+char *P_GetInterBackrop(const int ep, const int map);
+int P_GetInterMusic(const int ep, const int map);
+char *P_GetInterText(const int ep, const int map);
+char *P_GetInterSecretText(const int ep, const int map);
+bool P_GetMapEndBunny(const int ep, const int map);
+bool P_GetMapEndCast(const int ep, const int map);
+bool P_GetMapEndGame(const int ep, const int map);
+int P_GetMapEndPic(const int ep, const int map);
+int P_GetMapEnterPic(const int ep, const int map);
+int P_GetMapExitPic(const int ep, const int map);
+void P_GetMapLiquids(const int ep, const int map);
+int P_GetMapMusic(const int ep, const int map);
+char *P_GetMapMusicComposer(const int ep, const int map);
+char *P_GetMapMusicTitle(const int ep, const int map);
+char *P_GetMapName(const int ep, const int map);
+int P_GetMapNext(const int ep, const int map);
+void P_GetMapNoLiquids(const int ep, const int map);
+int P_GetMapPar(const int ep, const int map);
+bool P_GetMapPistolStart(const int ep, const int map);
+int P_GetMapSecretNext(const int ep, const int map);
+int P_GetMapSky1Texture(const int ep, const int map);
+int P_GetMapSky1ScrollDelta(const int ep, const int map);
+int P_GetMapTitlePatch(const int ep, const int map);
+int P_GetAllowMonsterTelefrags(const int ep, const int map);
diff --git a/src/r_sky.c b/src/r_sky.c
index bbb8905741..401afacbf3 100644
--- a/src/r_sky.c
+++ b/src/r_sky.c
@@ -54,11 +54,9 @@ bool    canmouselook = false;
 
 void R_InitSkyMap(void)
 {
-    const int   map = (gameepisode - 1) * 10 + gamemap;
-
     skyflatnum = R_FlatNumForName(SKYFLATNAME);
     terraintypes[skyflatnum] = SKY;
-    skytexture = P_GetMapSky1Texture(map);
+    skytexture = P_GetMapSky1Texture(gameepisode, gamemap);
     canmouselook = ((mouselook || keyboardmouselook || mousemouselook != -1 || autotilt
         || (weaponrecoil && r_screensize == r_screensize_max)) && !nomouselook);
 
@@ -111,7 +109,7 @@ void R_InitSkyMap(void)
         }
     }
 
-    skyscrolldelta = P_GetMapSky1ScrollDelta(map);
+    skyscrolldelta = P_GetMapSky1ScrollDelta(gameepisode, gamemap);
 
     if (canmouselook)
     {
diff --git a/src/s_sound.c b/src/s_sound.c
index c1262c4c05..cce1486ae4 100644
--- a/src/s_sound.c
+++ b/src/s_sound.c
@@ -608,7 +608,7 @@ void S_ChangeMusic(musicnum_t musicnum, bool looping, bool allowrestart, bool ma
         else
             music->lumpnum = W_CheckNumForName(namebuf);
     }
-    else if (mapstart && (mapinfomusic = P_GetMapMusic((gameepisode - 1) * 10 + gamemap)) > 0)
+    else if (mapstart && (mapinfomusic = P_GetMapMusic(gameepisode, gamemap)) > 0)
         music->lumpnum = mapinfomusic;
     else if (!music->lumpnum)
         music->lumpnum = W_CheckNumForName(namebuf);
diff --git a/src/wi_stuff.c b/src/wi_stuff.c
index 3deda25825..1c5b923c93 100644
--- a/src/wi_stuff.c
+++ b/src/wi_stuff.c
@@ -368,7 +368,7 @@ static void WI_DrawLF(void)
 {
     const int   x = (VANILLAWIDTH - SHORT(finished->width)) / 2;
     int         y = WI_TITLEY;
-    const int   titlepatch = P_GetMapTitlePatch(wbs->epsd * 10 + wbs->last + 1);
+    const int   titlepatch = P_GetMapTitlePatch(wbs->epsd, wbs->last + 1);
 
     // draw <LevelName>
     if (titlepatch > 0)
@@ -426,7 +426,7 @@ static void WI_DrawEL(void)
 {
     const int   x = (VANILLAWIDTH - SHORT(entering->width)) / 2;
     int         y = WI_TITLEY;
-    const int   titlepatch = P_GetMapTitlePatch(wbs->epsd * 10 + wbs->next + 1);
+    const int   titlepatch = P_GetMapTitlePatch(wbs->epsd, wbs->next + 1);
 
     // draw "Entering"
     if (SHORT(entering->height) < VANILLAHEIGHT)
@@ -735,7 +735,7 @@ static void WI_UpdateShowNextLoc(void)
 
 static void WI_DrawShowNextLoc(void)
 {
-    if (P_GetMapEndGame(gamemap) || P_GetMapEndCast(gamemap))
+    if (P_GetMapEndGame(gameepisode, gamemap) || P_GetMapEndCast(gameepisode, gamemap))
         return;
 
     WI_SlamBackground();
@@ -1268,8 +1268,8 @@ static void WI_InitVariables(wbstartstruct_t *wbstartstruct)
 
     wbs = wbstartstruct;
 
-    enterpic = P_GetMapEnterPic(wbs->next + 1);
-    exitpic = P_GetMapExitPic(gamemap);
+    enterpic = P_GetMapEnterPic(wbs->epsd, wbs->next + 1);
+    exitpic = P_GetMapExitPic(gameepisode, gamemap);
 
     acceleratestage = false;
     cnt = 0;