diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index 249ddebdd605..80a1ae9e8ae1 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -2760,7 +2760,7 @@ export default class BattleScene extends SceneBase {
     const previousEncounter = this.mysteryEncounterData.encounteredEvents?.length > 0 ? this.mysteryEncounterData.encounteredEvents[this.mysteryEncounterData.encounteredEvents.length - 1][0] : null;
     const biomeMysteryEncounters = mysteryEncountersByBiome.get(this.arena.biomeType) ?? [];
     // If no valid encounters exist at tier, checks next tier down, continuing until there are some encounters available
-    while (availableEncounters.length === 0 && tier >= 0) {
+    while (availableEncounters.length === 0 && tier !== null) {
       availableEncounters = biomeMysteryEncounters
         .filter((encounterType) => {
           const encounterCandidate = allMysteryEncounters[encounterType];
@@ -2784,7 +2784,16 @@ export default class BattleScene extends SceneBase {
           return true;
         })
         .map((m) => (allMysteryEncounters[m]));
-      tier--;
+      // Decrement tier
+      if (tier === MysteryEncounterTier.ROGUE) {
+        tier = MysteryEncounterTier.ULTRA;
+      } else if (tier === MysteryEncounterTier.ULTRA) {
+        tier = MysteryEncounterTier.GREAT;
+      } else if (tier === MysteryEncounterTier.GREAT) {
+        tier = MysteryEncounterTier.COMMON;
+      } else {
+        tier = null; // Ends loop
+      }
     }
 
     // If absolutely no encounters are available, spawn 0th encounter
diff --git a/src/test/mystery-encounter/encounters/absolute-avarice-encounter.test.ts b/src/test/mystery-encounter/encounters/absolute-avarice-encounter.test.ts
index e80b5821dbf2..d21421cde2b6 100644
--- a/src/test/mystery-encounter/encounters/absolute-avarice-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/absolute-avarice-encounter.test.ts
@@ -81,6 +81,7 @@ describe("Absolute Avarice - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of proper biomes", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.GREAT);
     game.override.startingBiome(Biome.VOLCANO);
     await game.runToMysteryEncounter();
 
@@ -96,6 +97,7 @@ describe("Absolute Avarice - Mystery Encounter", () => {
   });
 
   it("should spawn if player has enough berries", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.GREAT);
     game.override.starterHeldItems([{name: "BERRY", count: 2, type: BerryType.SITRUS}, {name: "BERRY", count: 3, type: BerryType.GANLON}]);
 
     await game.runToMysteryEncounter();
diff --git a/src/test/mystery-encounter/encounters/an-offer-you-cant-refuse-encounter.test.ts b/src/test/mystery-encounter/encounters/an-offer-you-cant-refuse-encounter.test.ts
index 6b4405a779bd..128a4c109dc2 100644
--- a/src/test/mystery-encounter/encounters/an-offer-you-cant-refuse-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/an-offer-you-cant-refuse-encounter.test.ts
@@ -72,6 +72,7 @@ describe("An Offer You Can't Refuse - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of HUMAN_TRANSITABLE_BIOMES", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.GREAT);
     game.override.startingBiome(Biome.VOLCANO);
     await game.runToMysteryEncounter();
 
diff --git a/src/test/mystery-encounter/encounters/department-store-sale-encounter.test.ts b/src/test/mystery-encounter/encounters/department-store-sale-encounter.test.ts
index 016dbcee9649..1ffd17085237 100644
--- a/src/test/mystery-encounter/encounters/department-store-sale-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/department-store-sale-encounter.test.ts
@@ -72,6 +72,7 @@ describe("Department Store Sale - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of CIVILIZATION_ENCOUNTER_BIOMES", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.COMMON);
     game.override.startingBiome(Biome.VOLCANO);
     await game.runToMysteryEncounter();
 
diff --git a/src/test/mystery-encounter/encounters/lost-at-sea-encounter.test.ts b/src/test/mystery-encounter/encounters/lost-at-sea-encounter.test.ts
index 0e4d56c9fc14..c9d2d276ecb3 100644
--- a/src/test/mystery-encounter/encounters/lost-at-sea-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/lost-at-sea-encounter.test.ts
@@ -66,6 +66,7 @@ describe("Lost at Sea - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of sea biome", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.COMMON);
     game.override.startingBiome(Biome.MOUNTAIN);
     await game.runToMysteryEncounter();
 
diff --git a/src/test/mystery-encounter/encounters/mysterious-challengers-encounter.test.ts b/src/test/mystery-encounter/encounters/mysterious-challengers-encounter.test.ts
index 94a7161a9cd0..7fe6b1a3f95b 100644
--- a/src/test/mystery-encounter/encounters/mysterious-challengers-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/mysterious-challengers-encounter.test.ts
@@ -71,6 +71,7 @@ describe("Mysterious Challengers - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of HUMAN_TRANSITABLE_BIOMES", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.GREAT);
     game.override.startingBiome(Biome.VOLCANO);
     await game.runToMysteryEncounter();
 
@@ -86,7 +87,6 @@ describe("Mysterious Challengers - Mystery Encounter", () => {
   });
 
   it("should not run above wave 179", async () => {
-    game.override.mysteryEncounterTier(MysteryEncounterTier.GREAT);
     game.override.startingWave(181);
 
     await game.runToMysteryEncounter();
diff --git a/src/test/mystery-encounter/encounters/the-pokemon-salesman-encounter.test.ts b/src/test/mystery-encounter/encounters/the-pokemon-salesman-encounter.test.ts
index 966d97634404..833503e2636c 100644
--- a/src/test/mystery-encounter/encounters/the-pokemon-salesman-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/the-pokemon-salesman-encounter.test.ts
@@ -69,6 +69,7 @@ describe("The Pokemon Salesman - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of HUMAN_TRANSITABLE_BIOMES", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.ULTRA);
     game.override.startingBiome(Biome.VOLCANO);
     await game.runToMysteryEncounter();
 
diff --git a/src/test/mystery-encounter/encounters/the-strong-stuff-encounter.test.ts b/src/test/mystery-encounter/encounters/the-strong-stuff-encounter.test.ts
index bcfdad48ad35..21d0678c858e 100644
--- a/src/test/mystery-encounter/encounters/the-strong-stuff-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/the-strong-stuff-encounter.test.ts
@@ -75,6 +75,7 @@ describe("The Strong Stuff - Mystery Encounter", () => {
   });
 
   it("should not spawn outside of CAVE biome", async () => {
+    game.override.mysteryEncounterTier(MysteryEncounterTier.COMMON);
     game.override.startingBiome(Biome.MOUNTAIN);
     await game.runToMysteryEncounter();