diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index 95ecc9c17af..458226d1c1a 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -604,20 +604,18 @@ export abstract class Pokemon extends Phaser.GameObjects.Container {
 
   /** Generate `abilityIndex` based on species and hidden ability if not pre-defined. */
   private generateAbilityIndex(): number {
-    // Roll for hidden ability chance, applying any ability charms for enemy mons
     const hiddenAbilityChance = new NumberHolder(BASE_HIDDEN_ABILITY_CHANCE);
+    // Ability Charms should only affect wild Pokemon
+    // TODO: move this `if` check into the ability charm code
     if (!this.hasTrainer()) {
       globalScene.applyModifiers(HiddenAbilityRateBoosterModifier, true, hiddenAbilityChance);
     }
 
-    // If the roll succeeded and we have one, use HA; otherwise pick a random ability
-    const hasHiddenAbility = !randSeedInt(hiddenAbilityChance.value);
-    if (this.species.abilityHidden && hasHiddenAbility) {
-      return 2;
-    }
+    // Neither RNG roll depends on the outcome of the other, so that Ability Charms do not affect RNG.
+    const regularAbility = this.species.ability2 !== this.species.ability1 ? randSeedInt(2) : 0;
+    const useHiddenAbility = this.species.abilityHidden ? !randSeedInt(hiddenAbilityChance.value) : false;
 
-    // only use random ability if species has a second ability
-    return this.species.ability2 !== this.species.ability1 ? randSeedInt(2) : 0;
+    return useHiddenAbility ? 2 : regularAbility;
   }
 
   /**