diff --git a/src/phases/stat-stage-change-phase.ts b/src/phases/stat-stage-change-phase.ts
index bbba644f70f0..1af9481ed5fe 100644
--- a/src/phases/stat-stage-change-phase.ts
+++ b/src/phases/stat-stage-change-phase.ts
@@ -1,6 +1,6 @@
 import BattleScene from "#app/battle-scene.js";
 import { BattlerIndex } from "#app/battle.js";
-import { applyPreStatStageChangeAbAttrs, ProtectStatAbAttr, applyAbAttrs, StatMultiplierAbAttr, StatStageChangeCopyAbAttr, applyPostStatStageChangeAbAttrs, PostStatStageChangeAbAttr } from "#app/data/ability.js";
+import { applyPreStatStageChangeAbAttrs, ProtectStatAbAttr, applyAbAttrs, StatStageChangeMultiplierAbAttr, StatStageChangeCopyAbAttr, applyPostStatStageChangeAbAttrs, PostStatStageChangeAbAttr } from "#app/data/ability.js";
 import { MistTag, ArenaTagSide } from "#app/data/arena-tag.js";
 import Pokemon from "#app/field/pokemon.js";
 import { getPokemonNameWithAffix } from "#app/messages.js";
@@ -59,7 +59,7 @@ export class StatStageChangePhase extends PokemonPhase {
     const stages = new Utils.IntegerHolder(this.stages);
 
     if (!this.ignoreAbilities) {
-      applyAbAttrs(StatMultiplierAbAttr, pokemon, null, stages);
+      applyAbAttrs(StatStageChangeMultiplierAbAttr, pokemon, null, stages);
     }
 
     const relLevels = filteredStats.map(s => (stages.value >= 1 ? Math.min(pokemon.getStatStage(s) + stages.value, 6) : Math.max(pokemon.getStatStage(s) + stages.value, -6)) - pokemon.getStatStage(s));
diff --git a/src/test/abilities/contrary.test.ts b/src/test/abilities/contrary.test.ts
new file mode 100644
index 000000000000..75085874fb60
--- /dev/null
+++ b/src/test/abilities/contrary.test.ts
@@ -0,0 +1,41 @@
+import { Stat } from "#enums/stat";
+import GameManager from "#test/utils/gameManager";
+import { Abilities } from "#enums/abilities";
+import { Species } from "#enums/species";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+import { SPLASH_ONLY } from "../utils/testUtils";
+
+describe("Abilities - Contrary", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override.battleType("single");
+    game.override.enemySpecies(Species.BULBASAUR);
+    game.override.enemyAbility(Abilities.CONTRARY);
+    game.override.ability(Abilities.INTIMIDATE);
+    game.override.enemyMoveset(SPLASH_ONLY);
+  });
+
+  it("should invert stat changes when applied", async() => {
+    await game.startBattle([
+      Species.SLOWBRO
+    ]);
+
+    const enemyPokemon = game.scene.getEnemyPokemon()!;
+
+    expect(enemyPokemon.getStatStage(Stat.ATK)).toBe(1);
+  }, 20000);
+});
diff --git a/src/test/abilities/simple.test.ts b/src/test/abilities/simple.test.ts
new file mode 100644
index 000000000000..45d2cc34b39f
--- /dev/null
+++ b/src/test/abilities/simple.test.ts
@@ -0,0 +1,41 @@
+import { Stat } from "#enums/stat";
+import GameManager from "#test/utils/gameManager";
+import { Abilities } from "#enums/abilities";
+import { Species } from "#enums/species";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+import { SPLASH_ONLY } from "../utils/testUtils";
+
+describe("Abilities - Simple", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override.battleType("single");
+    game.override.enemySpecies(Species.BULBASAUR);
+    game.override.enemyAbility(Abilities.SIMPLE);
+    game.override.ability(Abilities.INTIMIDATE);
+    game.override.enemyMoveset(SPLASH_ONLY);
+  });
+
+  it("should double stat changes when applied", async() => {
+    await game.startBattle([
+      Species.SLOWBRO
+    ]);
+
+    const enemyPokemon = game.scene.getEnemyPokemon()!;
+
+    expect(enemyPokemon.getStatStage(Stat.ATK)).toBe(-2);
+  }, 20000);
+});