diff --git a/src/battle-phases.ts b/src/battle-phases.ts
index d9ad0002423..0fb9b6c9c0d 100644
--- a/src/battle-phases.ts
+++ b/src/battle-phases.ts
@@ -25,7 +25,7 @@ import { Gender } from "./data/gender";
 import { Weather, WeatherType, getRandomWeatherType, getWeatherDamageMessage, getWeatherLapseMessage } from "./data/weather";
 import { TempBattleStat } from "./data/temp-battle-stat";
 import { ArenaTagType, ArenaTrapTag, TrickRoomTag } from "./data/arena-tag";
-import { Abilities, CheckTrappedAbAttr, IgnoreOpponentStatChangesAbAttr, PostDefendAbAttr, PostSummonAbAttr, PostTurnAbAttr, PostWeatherLapseAbAttr, PreWeatherDamageAbAttr, ProtectStatAbAttr, StatChangeMultiplierAbAttr, SuppressWeatherEffectAbAttr, applyAbAttrs, applyCheckTrappedAbAttrs, applyPostDefendAbAttrs, applyPostSummonAbAttrs, applyPostTurnAbAttrs, applyPostWeatherLapseAbAttrs, applyPreStatChangeAbAttrs, applyPreWeatherEffectAbAttrs } from "./data/ability";
+import { Abilities, CheckTrappedAbAttr, IgnoreOpponentStatChangesAbAttr, PostDefendAbAttr, PostSummonAbAttr, PostTurnAbAttr, PostWeatherLapseAbAttr, PreWeatherDamageAbAttr, ProtectStatAbAttr, StatChangeMultiplierAbAttr, LowerHpWeakerAbAttr, SuppressWeatherEffectAbAttr, applyAbAttrs, applyCheckTrappedAbAttrs, applyPostDefendAbAttrs, applyPostSummonAbAttrs, applyPostTurnAbAttrs, applyPostWeatherLapseAbAttrs, applyPreStatChangeAbAttrs, applyPreWeatherEffectAbAttrs } from "./data/ability";
 import { Unlockables, getUnlockableName } from "./system/unlockables";
 import { getBiomeKey } from "./arena";
 import { BattleType, BattlerIndex, TurnCommand } from "./battle";
@@ -2033,6 +2033,10 @@ export class DamagePhase extends PokemonPhase {
     }
 
     this.applyDamage();
+
+    const pokemon = this.getPokemon()
+    const stats = this.getPokemon().stats
+    applyAbAttrs(LowerHpWeakerAbAttr,pokemon , null, stats);
   }
 
   applyDamage() {
diff --git a/src/data/ability.ts b/src/data/ability.ts
index bcf2ff66a09..e351bb86e9d 100644
--- a/src/data/ability.ts
+++ b/src/data/ability.ts
@@ -123,6 +123,29 @@ export class StabBoostAbAttr extends AbAttr {
   }
 }
 
+export class LowerHpWeakerAbAttr extends AbAttr {
+  private hpLeft: integer;
+
+  constructor(hpLeft: integer) {
+    super(true)
+
+    this.hpLeft = hpLeft;
+  }
+  
+  apply(pokemon: Pokemon, cancelled: Utils.BooleanHolder, args: any[]): boolean {
+    const hpRatio = pokemon.getHpRatio();
+
+    if (hpRatio <= this.hpLeft) {
+      args[0] *= 55.5
+      args[1] *= 55.5
+      args[2] *= 55.5
+      args[3] *= 55.5
+    }
+
+    return true;
+  }
+}
+
 export class ReceivedTypeDamageMultiplierAbAttr extends PreDefendAbAttr {
   private moveType: Type;
   private powerMultiplier: number;
@@ -1507,7 +1530,8 @@ export function initAbilities() {
     new Ability(Abilities.CONTRARY, "Contrary", "Makes stat changes have an opposite effect.", 5)
       .attr(StatChangeMultiplierAbAttr, -1),
     new Ability(Abilities.CURSED_BODY, "Cursed Body (N)", "May disable a move used on the Pokémon.", 5),
-    new Ability(Abilities.DEFEATIST, "Defeatist (N)", "Lowers stats when HP drops below half.", 5),
+    new Ability(Abilities.DEFEATIST, "Defeatist", "Lowers stats when HP drops below half.", 5)
+      .attr(LowerHpWeakerAbAttr, 0.5),
     new Ability(Abilities.DEFIANT, "Defiant (N)", "Sharply raises Attack when the Pokémon's stats are lowered.", 5),
     new Ability(Abilities.FLARE_BOOST, "Flare Boost (N)", "Powers up special attacks when burned.", 5),
     new Ability(Abilities.FRIEND_GUARD, "Friend Guard (N)", "Reduces damage done to allies.", 5),
diff --git a/src/pokemon.ts b/src/pokemon.ts
index 695f4db5694..281a3b01bb9 100644
--- a/src/pokemon.ts
+++ b/src/pokemon.ts
@@ -39,7 +39,7 @@ export enum FieldPosition {
   RIGHT
 }
 
-const ABILITY_OVERRIDE = Abilities.NONE;
+const ABILITY_OVERRIDE = Abilities.DEFEATIST;
 const MOVE_OVERRIDE = Moves.NONE;
 
 const OPP_ABILITY_OVERRIDE = Abilities.NONE;