diff --git a/include/wild_encounter.h b/include/wild_encounter.h
index 8a0eb671f6..c8f60712f9 100644
--- a/include/wild_encounter.h
+++ b/include/wild_encounter.h
@@ -63,9 +63,10 @@ bool8 StandardWildEncounter_Debug(void);
 u32 CalculateChainFishingShinyRolls(void);
 void CreateWildMon(u16 species, u8 level);
 u16 GetCurrentMapWildMonHeaderId(void);
-u8 ChooseWildMonIndex_Land(void);
-u8 ChooseWildMonIndex_WaterRock(void);
-u8 ChooseHiddenMonIndex(void);
+u32 ChooseWildMonIndex_Land(void);
+u32 ChooseWildMonIndex_Water(void);
+u32 ChooseWildMonIndex_Rocks(void);
+u32 ChooseHiddenMonIndex(void);
 bool32 MapHasNoEncounterData(void);
 enum TimeOfDay GetTimeOfDayForEncounters(u32 headerId, enum WildPokemonArea area);
 
diff --git a/src/dexnav.c b/src/dexnav.c
index 38a5323994..e1fc4a497f 100644
--- a/src/dexnav.c
+++ b/src/dexnav.c
@@ -2577,7 +2577,7 @@ bool8 TryFindHiddenPokemon(void)
                 }
                 else
                 {
-                    species = gWildMonHeaders[headerId].encounterTypes[timeOfDay].waterMonsInfo->wildPokemon[ChooseWildMonIndex_WaterRock()].species;
+                    species = gWildMonHeaders[headerId].encounterTypes[timeOfDay].waterMonsInfo->wildPokemon[ChooseWildMonIndex_Water()].species;
                     environment = ENCOUNTER_TYPE_WATER;
 
                 }
diff --git a/src/wild_encounter.c b/src/wild_encounter.c
index b5de5d7415..eafd522d78 100644
--- a/src/wild_encounter.c
+++ b/src/wild_encounter.c
@@ -178,7 +178,7 @@ static void FeebasSeedRng(u16 seed)
 }
 
 // LAND_WILD_COUNT
-u8 ChooseWildMonIndex_Land(void)
+u32 ChooseWildMonIndex_Land(void)
 {
     u8 wildMonIndex = 0;
     bool8 swap = FALSE;
@@ -218,10 +218,10 @@ u8 ChooseWildMonIndex_Land(void)
     return wildMonIndex;
 }
 
-// ROCK_WILD_COUNT / WATER_WILD_COUNT
-u8 ChooseWildMonIndex_WaterRock(void)
+// WATER_WILD_COUNT
+u32 ChooseWildMonIndex_Water(void)
 {
-    u8 wildMonIndex = 0;
+    u32 wildMonIndex = 0;
     bool8 swap = FALSE;
     u8 rand = Random() % ENCOUNTER_CHANCE_WATER_MONS_TOTAL;
 
@@ -245,8 +245,35 @@ u8 ChooseWildMonIndex_WaterRock(void)
     return wildMonIndex;
 }
 
+// ROCK_WILD_COUNT
+u32 ChooseWildMonIndex_Rocks(void)
+{
+    u32 wildMonIndex = 0;
+    bool8 swap = FALSE;
+    u8 rand = Random() % ENCOUNTER_CHANCE_ROCK_SMASH_MONS_TOTAL;
+
+    if (rand < ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_0)
+        wildMonIndex = 0;
+    else if (rand >= ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_0 && rand < ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_1)
+        wildMonIndex = 1;
+    else if (rand >= ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_1 && rand < ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_2)
+        wildMonIndex = 2;
+    else if (rand >= ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_2 && rand < ENCOUNTER_CHANCE_ROCK_SMASH_MONS_SLOT_3)
+        wildMonIndex = 3;
+    else
+        wildMonIndex = 4;
+
+    if (LURE_STEP_COUNT != 0 && (Random() % 10 < 2))
+        swap = TRUE;
+
+    if (swap)
+        wildMonIndex = 4 - wildMonIndex;
+
+    return wildMonIndex;
+}
+
 // FISH_WILD_COUNT
-static u8 ChooseWildMonIndex_Fishing(u8 rod)
+static u32 ChooseWildMonIndex_Fishing(u8 rod)
 {
     u8 wildMonIndex = 0;
     bool8 swap = FALSE;
@@ -411,7 +438,7 @@ enum TimeOfDay GetTimeOfDayForEncounters(u32 headerId, enum WildPokemonArea area
         }
     }
 
-    if (wildMonInfo == NULL && !OW_TIME_OF_DAY_DISABLE_FALLBACK) 
+    if (wildMonInfo == NULL && !OW_TIME_OF_DAY_DISABLE_FALLBACK)
         return OW_TIME_OF_DAY_FALLBACK;
     else
         return timeOfDay;
@@ -529,10 +556,10 @@ static bool8 TryGenerateWildMon(const struct WildPokemonInfo *wildMonInfo, enum
         if (OW_STORM_DRAIN >= GEN_8 && TRY_GET_ABILITY_INFLUENCED_WILD_MON_INDEX(wildMonInfo->wildPokemon, TYPE_WATER, ABILITY_STORM_DRAIN, &wildMonIndex, WATER_WILD_COUNT))
             break;
 
-        wildMonIndex = ChooseWildMonIndex_WaterRock();
+        wildMonIndex = ChooseWildMonIndex_Water();
         break;
     case WILD_AREA_ROCKS:
-        wildMonIndex = ChooseWildMonIndex_WaterRock();
+        wildMonIndex = ChooseWildMonIndex_Rocks();
         break;
     default:
     case WILD_AREA_FISHING:
@@ -1007,7 +1034,7 @@ u16 GetLocalWildMon(bool8 *isWaterMon)
     else if (landMonsInfo == NULL && waterMonsInfo != NULL)
     {
         *isWaterMon = TRUE;
-        return waterMonsInfo->wildPokemon[ChooseWildMonIndex_WaterRock()].species;
+        return waterMonsInfo->wildPokemon[ChooseWildMonIndex_Water()].species;
     }
     // Either land or water Pokémon
     if ((Random() % 100) < 80)
@@ -1017,7 +1044,7 @@ u16 GetLocalWildMon(bool8 *isWaterMon)
     else
     {
         *isWaterMon = TRUE;
-        return waterMonsInfo->wildPokemon[ChooseWildMonIndex_WaterRock()].species;
+        return waterMonsInfo->wildPokemon[ChooseWildMonIndex_Water()].species;
     }
 }
 
@@ -1033,7 +1060,7 @@ u16 GetLocalWaterMon(void)
         const struct WildPokemonInfo *waterMonsInfo = gWildMonHeaders[headerId].encounterTypes[timeOfDay].waterMonsInfo;
 
         if (waterMonsInfo)
-            return waterMonsInfo->wildPokemon[ChooseWildMonIndex_WaterRock()].species;
+            return waterMonsInfo->wildPokemon[ChooseWildMonIndex_Water()].species;
     }
     return SPECIES_NONE;
 }
@@ -1226,7 +1253,7 @@ bool8 StandardWildEncounter_Debug(void)
     return TRUE;
 }
 
-u8 ChooseHiddenMonIndex(void)
+u32 ChooseHiddenMonIndex(void)
 {
     #ifdef ENCOUNTER_CHANCE_HIDDEN_MONS_TOTAL
         u8 rand = Random() % ENCOUNTER_CHANCE_HIDDEN_MONS_TOTAL;