[Item] Add Light Ball, Thick Club, Metal Powder, and Quick Powder (#1899)

* Add Light Ball, Thick Club, and Metal/Quick Powder

* Fix Typo, Account for Fusions

* Fix Errors with Fusions

* Group Items into Generator

* Refactor Generator and Type, Fix Localization (en)

* Adjust Generator, Add Override Type

* Fix Enum Import

* Localize for de, es, fr, it, ko, zh_CN, zh_TW

* Add Unit Tests

* Add Type

* Fix Items Atlas

* Change Cubone Passive Ability, Adjust Weight

src/data/pokemon-species.ts

@@ -3327,7 +3327,7 @@ export const starterPassiveAbilities = {
   [Species.KRABBY]: Abilities.UNBURDEN,
   [Species.VOLTORB]: Abilities.ELECTRIC_SURGE,
   [Species.EXEGGCUTE]: Abilities.RIPEN,
-  [Species.CUBONE]: Abilities.HUGE_POWER,
+  [Species.CUBONE]: Abilities.PARENTAL_BOND,
   [Species.LICKITUNG]: Abilities.THICK_FAT,
   [Species.KOFFING]: Abilities.PARENTAL_BOND,
   [Species.RHYHORN]: Abilities.FILTER,

src/field/pokemon.ts

@@ -10,7 +10,7 @@ import * as Utils from "../utils";
 import { Type, TypeDamageMultiplier, getTypeDamageMultiplier, getTypeRgb } from "../data/type";
 import { getLevelTotalExp } from "../data/exp";
 import { Stat } from "../data/pokemon-stat";
-import { AttackTypeBoosterModifier, DamageMoneyRewardModifier, EnemyDamageBoosterModifier, EnemyDamageReducerModifier, EnemyEndureChanceModifier, EnemyFusionChanceModifier, HiddenAbilityRateBoosterModifier, PokemonBaseStatModifier, PokemonFriendshipBoosterModifier, PokemonHeldItemModifier, PokemonMultiHitModifier, PokemonNatureWeightModifier, ShinyRateBoosterModifier, SurviveDamageModifier, TempBattleStatBoosterModifier, EvolutionStatBoosterModifier, TerastallizeModifier } from "../modifier/modifier";
+import { AttackTypeBoosterModifier, DamageMoneyRewardModifier, EnemyDamageBoosterModifier, EnemyDamageReducerModifier, EnemyEndureChanceModifier, EnemyFusionChanceModifier, HiddenAbilityRateBoosterModifier, PokemonBaseStatModifier, PokemonFriendshipBoosterModifier, PokemonHeldItemModifier, PokemonMultiHitModifier, PokemonNatureWeightModifier, ShinyRateBoosterModifier, SurviveDamageModifier, TempBattleStatBoosterModifier, StatBoosterModifier, TerastallizeModifier } from "../modifier/modifier";
 import { PokeballType } from "../data/pokeball";
 import { Gender } from "../data/gender";
 import { initMoveAnim, loadMoveAnimAssets } from "../data/battle-anims";
@@ -657,7 +657,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
       this.scene.applyModifiers(TempBattleStatBoosterModifier, this.isPlayer(), battleStat as integer as TempBattleStat, statLevel);
     }
     const statValue = new Utils.NumberHolder(this.getStat(stat));
-    this.scene.applyModifiers(EvolutionStatBoosterModifier, this.isPlayer(), this, stat, statValue);
+    this.scene.applyModifiers(StatBoosterModifier, this.isPlayer(), this, stat, statValue);
 
     const fieldApplied = new Utils.BooleanHolder(false);
     for (const pokemon of this.scene.getField(true)) {

src/interfaces/locales.ts

@@ -35,6 +35,7 @@ export interface ModifierTypeTranslationEntry {
 
 export interface ModifierTypeTranslationEntries {
     ModifierType: { [key: string]: ModifierTypeTranslationEntry },
+    SpeciesBoosterItem: { [key: string]: ModifierTypeTranslationEntry },
     AttackTypeBoosterItem: SimpleTranslationEntries,
     TempBattleStatBoosterItem: SimpleTranslationEntries,
     TempBattleStatBoosterStatName: SimpleTranslationEntries,

src/locales/de/modifier-type.ts

@@ -242,6 +242,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_FUSED_CHANCE": { "name": "Fusionsmarke", "description": "Fügt eine 1%ige Chance hinzu, dass ein wildes Pokémon eine Fusion ist." },
 
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "Kugelblitz", description: "Ein Item, das von Pikachu getragen werden kann. Es erhöht den Angriff und den Spezial-Angriff." },
+    "THICK_CLUB": { name: "Kampfknochen", description: "Ein Item, das von Tragosso oder Knogga getragen werden kann. Dieser harte Knochen erhöht den Angriff." },
+    "METAL_POWDER": { name: "Metallstaub", description: "Ein Item, das von Ditto getragen werden kann. Fein und doch hart, erhöht dieses sonderbare Pulver die Verteidigung." },
+    "QUICK_POWDER": { name: "Flottstaub", description: "Ein Item, das Ditto zum Tragen gegeben werden kann. Fein und doch hart, erhöht dieses sonderbare Pulver die Initiative." }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "X-Angriff",
     "x_defense": "X-Verteidigung",

src/locales/en/modifier-type.ts

@@ -241,6 +241,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "Endure Token" },
     "ENEMY_FUSED_CHANCE": { name: "Fusion Token", description: "Adds a 1% chance that a wild Pokémon will be a fusion." },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "Light Ball", description: "It's a mysterious orb that boosts Pikachu's Attack and Sp. Atk stats." },
+    "THICK_CLUB": { name: "Thick Club", description: "This hard bone of unknown origin boosts Cubone or Marowak's Attack stat." },
+    "METAL_POWDER": { name: "Metal Powder", description: "Extremely fine yet hard, this odd powder boosts Ditto's Defense stat." },
+    "QUICK_POWDER": { name: "Quick Powder", description: "Extremely fine yet hard, this odd powder boosts Ditto's Speed stat." }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "X Attack",
     "x_defense": "X Defense",

src/locales/es/modifier-type.ts

@@ -241,6 +241,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "Ficha Aguante" },
     "ENEMY_FUSED_CHANCE": { name: "Ficha Fusión", description: "Agrega un 1% de probabilidad de que un Pokémon salvaje sea una fusión." },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "Bola Luminosa", description: "Asombrosa esfera que aumenta el Ataque y el Ataque Especial. Debe llevarla Pikachu." },
+    "THICK_CLUB": { name: "Hueso Grueso", description: "Extraño tipo de hueso que potencia los ataques físicos. Debe llevarlo Cubone o Marowak." },
+    "METAL_POWDER": { name: "Polvo Metálico", description: "Polvo muy fino, pero a la vez poderoso, que aumenta la Defensa. Debe llevarlo Ditto." },
+    "QUICK_POWDER": { name: "Polvo Veloz", description: "Polvo muy fino, pero a la vez poderoso, que aumenta la Velocidad. Debe llevarlo Ditto." }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "Ataque X",
     "x_defense": "Defensa X",

src/locales/fr/modifier-type.ts

@@ -241,6 +241,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "Jeton Ténacité" },
     "ENEMY_FUSED_CHANCE": { name: "Jeton Fusion", description: "Ajoute 1% de chances qu’un Pokémon sauvage soit une fusion." },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "Balle Lumière", description: "Objet à faire tenir à Pikachu. Un orbe énigmatique qui augmente son Attaque et son Attaque Spéciale." },
+    "THICK_CLUB": { name: "Masse Os", description: "Objet à faire tenir à Osselait ou Ossatueur. Un os dur qui augmente leur Attaque." },
+    "METAL_POWDER": { name: "Poudre Métal", description: "Objet à faire tenir à Métamorph. Cette poudre étrange, très fine mais résistante, augmente sa Défense." },
+    "QUICK_POWDER": { name: "Poudre Vite", description: "Objet à faire tenir à Métamorph. Cette poudre étrange, très fine mais résistante, augmente sa Vitesse." }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "Attaque +",
     "x_defense": "Défense +",

src/locales/it/modifier-type.ts

@@ -241,6 +241,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "Gettone di Resistenza" },
     "ENEMY_FUSED_CHANCE": { name: "Gettone della fusione", description: "Aggiunge l'1% di possibilità che un Pokémon selvatico sia una fusione." },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "Elettropalla", description: "Strumento da dare a Pikachu. Sfera insolita che aumenta l’Attacco e l’Attacco Speciale." },
+    "THICK_CLUB": { name: "Osso spesso", description: "Strumento da dare a Cubone o Marowak. Osso duro che aumenta l’Attacco." },
+    "METAL_POWDER": { name: "Metalpolvere", description: "Strumento da dare a Ditto. Strana polvere finissima e al tempo stesso dura che migliora la Difesa." },
+    "QUICK_POWDER": { name: "Velopolvere", description: "Strumento da dare a Ditto. Questa strana polvere, fine e al contempo dura, aumenta la Velocità." }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "Attacco X",
     "x_defense": "Difesa X",

src/locales/ko/modifier-type.ts

@@ -241,6 +241,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "버티기 토큰" },
     "ENEMY_FUSED_CHANCE": { name: "합체 토큰", description: "야생 포켓몬이 합체되어 등장할 확률이 1% 추가된다." },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "전기구슬", description: "피카츄에게 지니게 하면 공격과 특수공격이 올라가는 이상한 구슬." },
+    "THICK_CLUB": { name: "굵은뼈", description: "무언가의 단단한 뼈. 탕구리 혹은 텅구리에게 지니게 하면 공격이 올라간다." },
+    "METAL_POWDER": { name: "금속파우더", description: "메타몽에게 지니게 하면 방어가 올라가는 이상한 가루. 매우 잘고 단단하다." },
+    "QUICK_POWDER": { name: "스피드파우더", description: "메타몽에게 지니게 하면 스피드가 올라가는 이상한 가루. 매우 잘고 단단하다." }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "플러스파워",
     "x_defense": "디펜드업",

src/locales/pt_BR/modifier-type.ts

@@ -241,6 +241,8 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "Token de Persistência" },
     "ENEMY_FUSED_CHANCE": { name: "Token de Fusão", description: "Adiciona uma chance de 1% de que um Pokémon selvagem seja uma fusão." },
   },
+  SpeciesBoosterItem: {
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "Ataque X",
     "x_defense": "Defesa X",

src/locales/zh_CN/modifier-type.ts

@@ -241,6 +241,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
     "ENEMY_ENDURE_CHANCE": { name: "忍受硬币" },
     "ENEMY_FUSED_CHANCE": { name: "融合硬币", description: "增加1%野生融合宝可梦出现概率。" },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "电气球", description: "让皮卡丘携带后，攻击和特攻就会 提高的神奇之球。" },
+    "THICK_CLUB": { name: "粗骨头", description: "某种坚硬的骨头。让卡拉卡拉或嘎啦嘎啦携带后，攻击就会提高。" },
+    "METAL_POWDER": { name: "金属粉", description: "让百变怪携带后，防御就会提高的神奇粉末。非常细腻坚硬。" },
+    "QUICK_POWDER": { name: "速度粉", description: "让百变怪携带后，速度就会提高的神奇粉末。非常细腻坚硬。" }
+  },
   TempBattleStatBoosterItem: {
     "x_attack": "力量强化",
     "x_defense": "防御强化",

src/locales/zh_TW/modifier-type.ts

@@ -301,6 +301,12 @@ export const modifierType: ModifierTypeTranslationEntries = {
       description: "增加1%野生融合寶可夢出現概率。",
     },
   },
+  SpeciesBoosterItem: {
+    "LIGHT_BALL": { name: "電氣球", description: "讓皮卡丘攜帶後，攻擊和特攻就會 提高的神奇之球。" },
+    "THICK_CLUB": { name: "粗骨頭", description: "某種堅硬的骨頭。讓卡拉卡拉或嘎啦嘎啦攜帶後，攻擊就會提高。" },
+    "METAL_POWDER": { name: "金屬粉", description: "讓百變怪攜帶後，防禦就會提高的神奇粉末。非常細緻堅硬。" },
+    "QUICK_POWDER": { name: "速度粉", description: "讓百變怪攜帶後，速度就會提高的神奇粉末。非常細緻堅硬。" }
+  },
   TempBattleStatBoosterItem: {
     x_attack: "力量強化",
     x_defense: "防禦強化",

src/modifier/modifier-type.ts

@@ -26,6 +26,7 @@ import { Abilities } from "#enums/abilities";
 import { BattlerTagType } from "#enums/battler-tag-type";
 import { BerryType } from "#enums/berry-type";
 import { Moves } from "#enums/moves";
+import { Species } from "#enums/species";
 
 const outputModifierData = false;
 const useMaxWeightForOutput = false;
@@ -539,6 +540,28 @@ export class AttackTypeBoosterModifierType extends PokemonHeldItemModifierType i
   }
 }
 
+export type SpeciesStatBoosterItem = keyof typeof SpeciesStatBoosterModifierTypeGenerator.items;
+
+/**
+ * Modifier type for {@linkcode Modifiers.SpeciesStatBoosterModifier}
+ * @extends PokemonHeldItemModifierType
+ * @implements GeneratedPersistentModifierType
+ */
+export class SpeciesStatBoosterModifierType extends PokemonHeldItemModifierType implements GeneratedPersistentModifierType {
+  private key: SpeciesStatBoosterItem;
+
+  constructor(key: SpeciesStatBoosterItem) {
+    const item = SpeciesStatBoosterModifierTypeGenerator.items[key];
+    super(`modifierType:SpeciesBoosterItem.${key}`, key.toLowerCase(), (type, args) => new Modifiers.SpeciesStatBoosterModifier(type, (args[0] as Pokemon).id, item.stats, item.multiplier, item.species));
+
+    this.id = this.key = key;
+  }
+
+  getPregenArgs(): any[] {
+    return [ this.key ];
+  }
+}
+
 export class PokemonLevelIncrementModifierType extends PokemonModifierType {
   constructor(localeKey: string, iconImage: string) {
     super(localeKey, iconImage, (_type, args) => new Modifiers.PokemonLevelIncrementModifier(this, (args[0] as PlayerPokemon).id), (_pokemon: PlayerPokemon) => null);
@@ -870,6 +893,81 @@ class AttackTypeBoosterModifierTypeGenerator extends ModifierTypeGenerator {
   }
 }
 
+/**
+ * Modifier type generator for {@linkcode SpeciesStatBoosterModifierType}, which
+ * encapsulates the logic for weighting the most useful held item from
+ * the current list of {@linkcode items}.
+ * @extends ModifierTypeGenerator
+ */
+class SpeciesStatBoosterModifierTypeGenerator extends ModifierTypeGenerator {
+  /** Object comprised of the currently available species-based stat boosting held items */
+  public static items = {
+    LIGHT_BALL: { stats: [Stat.ATK, Stat.SPATK], multiplier: 2, species: [Species.PIKACHU] },
+    THICK_CLUB: { stats: [Stat.ATK], multiplier: 2, species: [Species.CUBONE, Species.MAROWAK, Species.ALOLA_MAROWAK] },
+    METAL_POWDER: { stats: [Stat.DEF], multiplier: 2, species: [Species.DITTO] },
+    QUICK_POWDER: { stats: [Stat.SPD], multiplier: 2, species: [Species.DITTO] },
+  };
+
+  constructor() {
+    super((party: Pokemon[], pregenArgs?: any[]) => {
+      if (pregenArgs) {
+        return new SpeciesStatBoosterModifierType(pregenArgs[0] as SpeciesStatBoosterItem);
+      }
+
+      const values = Object.values(SpeciesStatBoosterModifierTypeGenerator.items);
+      const keys = Object.keys(SpeciesStatBoosterModifierTypeGenerator.items);
+      const weights = keys.map(() => 0);
+
+      for (const p of party) {
+        const speciesId = p.getSpeciesForm(true).speciesId;
+        const fusionSpeciesId = p.isFusion() ? p.getFusionSpeciesForm(true).speciesId : null;
+        const hasFling = p.getMoveset(true).some(m => m.moveId === Moves.FLING);
+
+        for (const i in values) {
+          const checkedSpecies = values[i].species;
+          const checkedStats = values[i].stats;
+
+          // If party member already has the item being weighted currently, skip to the next item
+          const hasItem = p.getHeldItems().some(m => m instanceof Modifiers.SpeciesStatBoosterModifier
+            && (m as Modifiers.SpeciesStatBoosterModifier).contains(checkedSpecies[0], checkedStats[0]));
+
+          if (!hasItem) {
+            if (checkedSpecies.includes(speciesId) || (!!fusionSpeciesId && checkedSpecies.includes(fusionSpeciesId))) {
+              // Add weight if party member has a matching species or, if applicable, a matching fusion species
+              weights[i]++;
+            } else if (checkedSpecies.includes(Species.PIKACHU) && hasFling) {
+              // Add weight to Light Ball if party member has Fling
+              weights[i]++;
+            }
+          }
+        }
+      }
+
+      let totalWeight = 0;
+      for (const weight of weights) {
+        totalWeight += weight;
+      }
+
+      if (totalWeight !== 0) {
+        const randInt = Utils.randSeedInt(totalWeight, 1);
+        let weight = 0;
+
+        for (const i in weights) {
+          if (weights[i] !== 0) {
+            const curWeight = weight + weights[i];
+            if (randInt <= weight + weights[i]) {
+              return new SpeciesStatBoosterModifierType(keys[i] as SpeciesStatBoosterItem);
+            }
+            weight = curWeight;
+          }
+        }
+      }
+
+      return null;
+    });
+  }
+}
+
 class TmModifierTypeGenerator extends ModifierTypeGenerator {
   constructor(tier: ModifierTier) {
     super((party: Pokemon[]) => {
@@ -1110,6 +1208,8 @@ export const modifierTypes = {
   SUPER_LURE: () => new DoubleBattleChanceBoosterModifierType("modifierType:ModifierType.SUPER_LURE", "super_lure", 10),
   MAX_LURE: () => new DoubleBattleChanceBoosterModifierType("modifierType:ModifierType.MAX_LURE", "max_lure", 25),
 
+  SPECIES_STAT_BOOSTER: () => new SpeciesStatBoosterModifierTypeGenerator(),
+
   TEMP_STAT_BOOSTER: () => new ModifierTypeGenerator((party: Pokemon[], pregenArgs?: any[]) => {
     if (pregenArgs) {
       return new TempBattleStatBoosterModifierType(pregenArgs[0] as TempBattleStat);
@@ -1369,6 +1469,7 @@ const modifierPool: ModifierPool = {
     new WeightedModifierType(modifierTypes.RARE_EVOLUTION_ITEM, (party: Pokemon[]) => Math.min(Math.ceil(party[0].scene.currentBattle.waveIndex / 15) * 4, 32), 32),
     new WeightedModifierType(modifierTypes.AMULET_COIN, 3),
     //new WeightedModifierType(modifierTypes.EVIOLITE, (party: Pokemon[]) => party.some(p => ((p.getSpeciesForm(true).speciesId in pokemonEvolutions) || (p.isFusion() && (p.getFusionSpeciesForm(true).speciesId in pokemonEvolutions))) && !p.getHeldItems().some(i => i instanceof Modifiers.EvolutionStatBoosterModifier)) ? 10 : 0),
+    new WeightedModifierType(modifierTypes.SPECIES_STAT_BOOSTER, 12),
     new WeightedModifierType(modifierTypes.TOXIC_ORB, (party: Pokemon[]) => {
       const checkedAbilities = [Abilities.QUICK_FEET, Abilities.GUTS, Abilities.MARVEL_SCALE, Abilities.TOXIC_BOOST, Abilities.POISON_HEAL, Abilities.MAGIC_GUARD];
       const checkedMoves = [Moves.FACADE, Moves.TRICK, Moves.FLING, Moves.SWITCHEROO, Moves.PSYCHO_SHIFT];

src/modifier/modifier.ts

@@ -23,6 +23,7 @@ import { Nature } from "#app/data/nature";
 import * as Overrides from "../overrides";
 import { ModifierType, modifierTypes } from "./modifier-type";
 import { Command } from "#app/ui/command-ui-handler.js";
+import { Species } from "#enums/species";
 
 import { allMoves } from "#app/data/move.js";
 import { Abilities } from "#app/enums/abilities.js";
@@ -707,16 +708,16 @@ export class PokemonBaseStatModifier extends PokemonHeldItemModifier {
 }
 
 /**
- * Modifier used for held items, specifically Eviolite, that apply
- * {@linkcode Stat} boost(s) using a multiplier if the holder can evolve.
+ * Modifier used for held items that apply {@linkcode Stat} boost(s)
+ * using a multiplier.
  * @extends PokemonHeldItemModifier
  * @see {@linkcode apply}
  */
-export class EvolutionStatBoosterModifier extends PokemonHeldItemModifier {
+export class StatBoosterModifier extends PokemonHeldItemModifier {
   /** The stats that the held item boosts */
-  private stats: Stat[];
+  protected stats: Stat[];
   /** The multiplier used to increase the relevant stat(s) */
-  private multiplier: number;
+  protected multiplier: number;
 
   constructor(type: ModifierType, pokemonId: integer, stats: Stat[], multiplier: number, stackCount?: integer) {
     super(type, pokemonId, stackCount);
@@ -726,7 +727,7 @@ export class EvolutionStatBoosterModifier extends PokemonHeldItemModifier {
   }
 
   clone() {
-    return new EvolutionStatBoosterModifier(this.type, this.pokemonId, this.stats, this.multiplier, this.stackCount);
+    return new StatBoosterModifier(this.type, this.pokemonId, this.stats, this.multiplier, this.stackCount);
   }
 
   getArgs(): any[] {
@@ -734,7 +735,14 @@ export class EvolutionStatBoosterModifier extends PokemonHeldItemModifier {
   }
 
   matchType(modifier: Modifier): boolean {
-    return modifier instanceof EvolutionStatBoosterModifier;
+    if (modifier instanceof StatBoosterModifier) {
+      const modifierInstance = modifier as StatBoosterModifier;
+      if ((modifierInstance.multiplier === this.multiplier) && (modifierInstance.stats.length === this.stats.length)) {
+        return modifierInstance.stats.every((e, i) => e === this.stats[i]);
+      }
+    }
+
+    return false;
   }
 
   /**
@@ -748,6 +756,42 @@ export class EvolutionStatBoosterModifier extends PokemonHeldItemModifier {
     return this.stats.includes(args[1] as Stat);
   }
 
+  /**
+   * Boosts the incoming stat by a {@linkcode multiplier} if the stat is listed
+   * in {@linkcode stats}.
+   * @param args [0] {@linkcode Pokemon} N/A
+   *             [1] {@linkcode Stat} N/A
+   *             [2] {@linkcode Utils.NumberHolder} that holds the resulting value of the stat
+   * @returns true if the stat boost applies successfully, false otherwise
+   * @see shouldApply
+   */
+  apply(args: any[]): boolean {
+    const statValue = args[2] as Utils.NumberHolder;
+
+    statValue.value *= this.multiplier;
+    return true;
+  }
+
+  getMaxHeldItemCount(_pokemon: Pokemon): number {
+    return 1;
+  }
+}
+
+/**
+ * Modifier used for held items, specifically Eviolite, that apply
+ * {@linkcode Stat} boost(s) using a multiplier if the holder can evolve.
+ * @extends StatBoosterModifier
+ * @see {@linkcode apply}
+ */
+export class EvolutionStatBoosterModifier extends StatBoosterModifier {
+  clone() {
+    return super.clone() as EvolutionStatBoosterModifier;
+  }
+
+  matchType(modifier: Modifier): boolean {
+    return modifier instanceof EvolutionStatBoosterModifier;
+  }
+
   /**
    * Boosts the incoming stat value by a {@linkcode multiplier} if the holder
    * can evolve. Note that, if the holder is a fusion, they will receive
@@ -771,15 +815,69 @@ export class EvolutionStatBoosterModifier extends PokemonHeldItemModifier {
       return true;
     } else if (isUnevolved) {
       // Full boost applied if holder is unfused and unevolved or, if fused, both parts of fusion are unevolved
-      statValue.value *= this.multiplier;
-      return true;
+      return super.apply(args);
+    }
+
+    return false;
+  }
+}
+
+/**
+ * Modifier used for held items that apply {@linkcode Stat} boost(s) using a
+ * multiplier if the holder is of a specific {@linkcode Species}.
+ * @extends StatBoosterModifier
+ * @see {@linkcode apply}
+ */
+export class SpeciesStatBoosterModifier extends StatBoosterModifier {
+  /** The species that the held item's stat boost(s) apply to */
+  private species: Species[];
+
+  constructor(type: ModifierType, pokemonId: integer, stats: Stat[], multiplier: number, species: Species[], stackCount?: integer) {
+    super(type, pokemonId, stats, multiplier, stackCount);
+
+    this.species = species;
+  }
+
+  clone() {
+    return new SpeciesStatBoosterModifier(this.type, this.pokemonId, this.stats, this.multiplier, this.species, this.stackCount);
+  }
+
+  getArgs(): any[] {
+    return [ ...super.getArgs(), this.species ];
+  }
+
+  matchType(modifier: Modifier): boolean {
+    if (modifier instanceof SpeciesStatBoosterModifier) {
+      const modifierInstance = modifier as SpeciesStatBoosterModifier;
+      if (modifierInstance.species.length === this.species.length) {
+        return super.matchType(modifier) && modifierInstance.species.every((e, i) => e === this.species[i]);
+      }
     }
 
     return false;
   }
 
-  getMaxHeldItemCount(_pokemon: Pokemon): integer {
-    return 1;
+  /**
+   * Checks if the incoming stat is listed in {@linkcode stats} and if the holder's {@linkcode Species}
+   * (or its fused species) is listed in {@linkcode species}.
+   * @param args [0] {@linkcode Pokemon} that holds the held item
+   *             [1] {@linkcode Stat} being checked at the time
+   *             [2] {@linkcode Utils.NumberHolder} N/A
+   * @returns true if the stat could be boosted, false otherwise
+   */
+  shouldApply(args: any[]): boolean {
+    const holder = args[0] as Pokemon;
+    return super.shouldApply(args) && (this.species.includes(holder.getSpeciesForm(true).speciesId) || (holder.isFusion() && this.species.includes(holder.getFusionSpeciesForm(true).speciesId)));
+  }
+
+  /**
+   * Checks if either parameter is included in the corresponding lists
+   * @param speciesId {@linkcode Species} being checked
+   * @param stat {@linkcode Stat} being checked
+   * @returns true if both parameters are in {@linkcode species} and {@linkcode stats} respectively, false otherwise
+   */
+  contains(speciesId: Species, stat: Stat): boolean {
+    return this.species.includes(speciesId) && this.stats.includes(stat);
   }
 }
 

src/overrides.ts

@@ -8,7 +8,7 @@ import { PokeballCounts } from "./battle-scene";
 import { PokeballType } from "./data/pokeball";
 import { Gender } from "./data/gender";
 import { StatusEffect } from "./data/status-effect";
-import { modifierTypes } from "./modifier/modifier-type";
+import { SpeciesStatBoosterItem, modifierTypes } from "./modifier/modifier-type";
 import { VariantTier } from "./enums/variant-tiers";
 import { EggTier } from "#enums/egg-type";
 import { allSpecies } from "./data/pokemon-species"; // eslint-disable-line @typescript-eslint/no-unused-vars
@@ -125,11 +125,12 @@ export const EGG_GACHA_PULL_COUNT_OVERRIDE: number = 0;
  * - Nature is for MINT
  * - Type is for TERA_SHARD or ATTACK_TYPE_BOOSTER (type boosting items i.e Silk Scarf)
  * - BerryType is for BERRY
+ * - SpeciesStatBoosterItem is for SPECIES_STAT_BOOSTER
  */
 interface ModifierOverride {
     name: keyof typeof modifierTypes & string,
     count?: integer
-    type?: TempBattleStat|Stat|Nature|Type|BerryType
+    type?: TempBattleStat|Stat|Nature|Type|BerryType|SpeciesStatBoosterItem
 }
 export const STARTING_MODIFIER_OVERRIDE: Array<ModifierOverride> = [];
 export const OPP_MODIFIER_OVERRIDE: Array<ModifierOverride> = [];

src/test/items/light_ball.test.ts

@@ -0,0 +1,200 @@
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import Phase from "phaser";
+import GameManager from "#app/test/utils/gameManager";
+import * as overrides from "#app/overrides";
+import { Species } from "#enums/species";
+import { Stat } from "#app/data/pokemon-stat";
+import { SpeciesStatBoosterModifier } from "#app/modifier/modifier";
+import { modifierTypes } from "#app/modifier/modifier-type";
+import * as Utils from "#app/utils";
+import i18next from "#app/plugins/i18n";
+
+describe("Items - Light Ball", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phase.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+
+    vi.spyOn(overrides, "SINGLE_BATTLE_OVERRIDE", "get").mockReturnValue(true);
+  });
+
+  it("LIGHT_BALL activates in battle correctly", async() => {
+    vi.spyOn(overrides, "STARTING_HELD_ITEMS_OVERRIDE", "get").mockReturnValue([{ name: "SPECIES_STAT_BOOSTER", type: "LIGHT_BALL" }]);
+    const consoleSpy = vi.spyOn(console, "log");
+    await game.startBattle([
+      Species.PIKACHU
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    // Checking consoe log to make sure Light Ball is applied when getBattleStat (with the appropriate stat) is called
+    partyMember.getBattleStat(Stat.DEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.LIGHT_BALL.name"), "");
+
+    // Printing dummy console messages along the way so subsequent checks don't pass because of the first
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPDEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.LIGHT_BALL.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.ATK);
+    expect(consoleSpy).toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.LIGHT_BALL.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPATK);
+    expect(consoleSpy).toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.LIGHT_BALL.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPD);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.LIGHT_BALL.name"), "");
+  });
+
+  it("LIGHT_BALL held by PIKACHU", async() => {
+    await game.startBattle([
+      Species.PIKACHU
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+    const spAtkStat = partyMember.getStat(Stat.SPATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, atkValue);
+    const spAtkValue = new Utils.NumberHolder(spAtkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPDEF, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+    expect(spAtkValue.value / spAtkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["LIGHT_BALL"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPATK, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+    expect(spAtkValue.value / spAtkStat).toBe(2);
+  }, 20000);
+
+  it("LIGHT_BALL held by fused PIKACHU (base)", async() => {
+    await game.startBattle([
+      Species.PIKACHU,
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+    const spAtkStat = partyMember.getStat(Stat.SPATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, atkValue);
+    const spAtkValue = new Utils.NumberHolder(spAtkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPDEF, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+    expect(spAtkValue.value / spAtkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["LIGHT_BALL"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPATK, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+    expect(spAtkValue.value / spAtkStat).toBe(2);
+  }, 20000);
+
+  it("LIGHT_BALL held by fused PIKACHU (part)", async() => {
+    await game.startBattle([
+      Species.MAROWAK,
+      Species.PIKACHU
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+    const spAtkStat = partyMember.getStat(Stat.SPATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, atkValue);
+    const spAtkValue = new Utils.NumberHolder(spAtkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPDEF, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+    expect(spAtkValue.value / spAtkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["LIGHT_BALL"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPATK, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+    expect(spAtkValue.value / spAtkStat).toBe(2);
+  }, 20000);
+
+  it("LIGHT_BALL not held by PIKACHU", async() => {
+    await game.startBattle([
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+    const spAtkStat = partyMember.getStat(Stat.SPATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, atkValue);
+    const spAtkValue = new Utils.NumberHolder(spAtkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPDEF, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+    expect(spAtkValue.value / spAtkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["LIGHT_BALL"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPATK, spAtkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+    expect(spAtkValue.value / spAtkStat).toBe(1);
+  }, 20000);
+});

src/test/items/metal_powder.test.ts

@@ -0,0 +1,176 @@
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import Phase from "phaser";
+import GameManager from "#app/test/utils/gameManager";
+import * as overrides from "#app/overrides";
+import { Species } from "#enums/species";
+import { Stat } from "#app/data/pokemon-stat";
+import { SpeciesStatBoosterModifier } from "#app/modifier/modifier";
+import { modifierTypes } from "#app/modifier/modifier-type";
+import * as Utils from "#app/utils";
+import i18next from "#app/plugins/i18n";
+
+describe("Items - Metal Powder", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phase.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+
+    vi.spyOn(overrides, "SINGLE_BATTLE_OVERRIDE", "get").mockReturnValue(true);
+  });
+
+  it("METAL_POWDER activates in battle correctly", async() => {
+    vi.spyOn(overrides, "STARTING_HELD_ITEMS_OVERRIDE", "get").mockReturnValue([{ name: "SPECIES_STAT_BOOSTER", type: "METAL_POWDER" }]);
+    const consoleSpy = vi.spyOn(console, "log");
+    await game.startBattle([
+      Species.DITTO
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    // Checking consoe log to make sure Metal Powder is applied when getBattleStat (with the appropriate stat) is called
+    partyMember.getBattleStat(Stat.DEF);
+    expect(consoleSpy).toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.METAL_POWDER.name"), "");
+
+    // Printing dummy console messages along the way so subsequent checks don't pass because of the first
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPDEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.METAL_POWDER.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.ATK);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.METAL_POWDER.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPATK);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.METAL_POWDER.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPD);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.METAL_POWDER.name"), "");
+  });
+
+  it("METAL_POWDER held by DITTO", async() => {
+    await game.startBattle([
+      Species.DITTO
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const defStat = partyMember.getStat(Stat.DEF);
+
+    // Making sure modifier is not applied without holding item
+    const defValue = new Utils.NumberHolder(defStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["METAL_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(2);
+  }, 20000);
+
+  it("METAL_POWDER held by fused DITTO (base)", async() => {
+    await game.startBattle([
+      Species.DITTO,
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const defStat = partyMember.getStat(Stat.DEF);
+
+    // Making sure modifier is not applied without holding item
+    const defValue = new Utils.NumberHolder(defStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["METAL_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(2);
+  }, 20000);
+
+  it("METAL_POWDER held by fused DITTO (part)", async() => {
+    await game.startBattle([
+      Species.MAROWAK,
+      Species.DITTO
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const defStat = partyMember.getStat(Stat.DEF);
+
+    // Making sure modifier is not applied without holding item
+    const defValue = new Utils.NumberHolder(defStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["METAL_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(2);
+  }, 20000);
+
+  it("METAL_POWDER not held by DITTO", async() => {
+    await game.startBattle([
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const defStat = partyMember.getStat(Stat.DEF);
+
+    // Making sure modifier is not applied without holding item
+    const defValue = new Utils.NumberHolder(defStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["METAL_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.DEF, defValue);
+
+    expect(defValue.value / defStat).toBe(1);
+  }, 20000);
+});

src/test/items/quick_powder.test.ts

@@ -0,0 +1,176 @@
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import Phase from "phaser";
+import GameManager from "#app/test/utils/gameManager";
+import * as overrides from "#app/overrides";
+import { Species } from "#enums/species";
+import { Stat } from "#app/data/pokemon-stat";
+import { SpeciesStatBoosterModifier } from "#app/modifier/modifier";
+import { modifierTypes } from "#app/modifier/modifier-type";
+import * as Utils from "#app/utils";
+import i18next from "#app/plugins/i18n";
+
+describe("Items - Quick Powder", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phase.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+
+    vi.spyOn(overrides, "SINGLE_BATTLE_OVERRIDE", "get").mockReturnValue(true);
+  });
+
+  it("QUICK_POWDER activates in battle correctly", async() => {
+    vi.spyOn(overrides, "STARTING_HELD_ITEMS_OVERRIDE", "get").mockReturnValue([{ name: "SPECIES_STAT_BOOSTER", type: "QUICK_POWDER" }]);
+    const consoleSpy = vi.spyOn(console, "log");
+    await game.startBattle([
+      Species.DITTO
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    // Checking consoe log to make sure Quick Powder is applied when getBattleStat (with the appropriate stat) is called
+    partyMember.getBattleStat(Stat.DEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.QUICK_POWDER.name"), "");
+
+    // Printing dummy console messages along the way so subsequent checks don't pass because of the first
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPDEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.QUICK_POWDER.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.ATK);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.QUICK_POWDER.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPATK);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.QUICK_POWDER.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPD);
+    expect(consoleSpy).toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.QUICK_POWDER.name"), "");
+  });
+
+  it("QUICK_POWDER held by DITTO", async() => {
+    await game.startBattle([
+      Species.DITTO
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const spdStat = partyMember.getStat(Stat.SPD);
+
+    // Making sure modifier is not applied without holding item
+    const spdValue = new Utils.NumberHolder(spdStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["QUICK_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(2);
+  }, 20000);
+
+  it("QUICK_POWDER held by fused DITTO (base)", async() => {
+    await game.startBattle([
+      Species.DITTO,
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const spdStat = partyMember.getStat(Stat.SPD);
+
+    // Making sure modifier is not applied without holding item
+    const spdValue = new Utils.NumberHolder(spdStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["QUICK_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(2);
+  }, 20000);
+
+  it("QUICK_POWDER held by fused DITTO (part)", async() => {
+    await game.startBattle([
+      Species.MAROWAK,
+      Species.DITTO
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const spdStat = partyMember.getStat(Stat.SPD);
+
+    // Making sure modifier is not applied without holding item
+    const spdValue = new Utils.NumberHolder(spdStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["QUICK_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(2);
+  }, 20000);
+
+  it("QUICK_POWDER not held by DITTO", async() => {
+    await game.startBattle([
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const spdStat = partyMember.getStat(Stat.SPD);
+
+    // Making sure modifier is not applied without holding item
+    const spdValue = new Utils.NumberHolder(spdStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["QUICK_POWDER"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.SPD, spdValue);
+
+    expect(spdValue.value / spdStat).toBe(1);
+  }, 20000);
+});

src/test/items/thick_club.test.ts

@@ -0,0 +1,228 @@
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import Phase from "phaser";
+import GameManager from "#app/test/utils/gameManager";
+import * as overrides from "#app/overrides";
+import { Species } from "#enums/species";
+import { Stat } from "#app/data/pokemon-stat";
+import { SpeciesStatBoosterModifier } from "#app/modifier/modifier";
+import { modifierTypes } from "#app/modifier/modifier-type";
+import * as Utils from "#app/utils";
+import i18next from "#app/plugins/i18n";
+
+describe("Items - Thick Club", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phase.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+
+    vi.spyOn(overrides, "SINGLE_BATTLE_OVERRIDE", "get").mockReturnValue(true);
+  });
+
+  it("THICK_CLUB activates in battle correctly", async() => {
+    vi.spyOn(overrides, "STARTING_HELD_ITEMS_OVERRIDE", "get").mockReturnValue([{ name: "SPECIES_STAT_BOOSTER", type: "THICK_CLUB" }]);
+    const consoleSpy = vi.spyOn(console, "log");
+    await game.startBattle([
+      Species.CUBONE
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    // Checking consoe log to make sure Thick Club is applied when getBattleStat (with the appropriate stat) is called
+    partyMember.getBattleStat(Stat.DEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.THICK_CLUB.name"), "");
+
+    // Printing dummy console messages along the way so subsequent checks don't pass because of the first
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPDEF);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.THICK_CLUB.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.ATK);
+    expect(consoleSpy).toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.THICK_CLUB.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPATK);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.THICK_CLUB.name"), "");
+
+    console.log("");
+
+    partyMember.getBattleStat(Stat.SPD);
+    expect(consoleSpy).not.toHaveBeenLastCalledWith("Applied", i18next.t("modifierType:SpeciesBoosterItem.THICK_CLUB.name"), "");
+  });
+
+  it("THICK_CLUB held by CUBONE", async() => {
+    await game.startBattle([
+      Species.CUBONE
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["THICK_CLUB"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+  }, 20000);
+
+  it("THICK_CLUB held by MAROWAK", async() => {
+    await game.startBattle([
+      Species.MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["THICK_CLUB"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+  }, 20000);
+
+  it("THICK_CLUB held by ALOLA_MAROWAK", async() => {
+    await game.startBattle([
+      Species.ALOLA_MAROWAK
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["THICK_CLUB"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+  }, 20000);
+
+  it("THICK_CLUB held by fused CUBONE line (base)", async() => {
+    // Randomly choose from the Cubone line
+    const species = [ Species.CUBONE, Species.MAROWAK, Species.ALOLA_MAROWAK ];
+    const randSpecies = Utils.randInt(species.length);
+
+    await game.startBattle([
+      species[randSpecies],
+      Species.PIKACHU
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["THICK_CLUB"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+  }, 20000);
+
+  it("THICK_CLUB held by fused CUBONE line (part)", async() => {
+    // Randomly choose from the Cubone line
+    const species = [ Species.CUBONE, Species.MAROWAK, Species.ALOLA_MAROWAK ];
+    const randSpecies = Utils.randInt(species.length);
+
+    await game.startBattle([
+      Species.PIKACHU,
+      species[randSpecies]
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+    const ally = game.scene.getParty()[1];
+
+    // Fuse party members (taken from PlayerPokemon.fuse(...) function)
+    partyMember.fusionSpecies = ally.species;
+    partyMember.fusionFormIndex = ally.formIndex;
+    partyMember.fusionAbilityIndex = ally.abilityIndex;
+    partyMember.fusionShiny = ally.shiny;
+    partyMember.fusionVariant = ally.variant;
+    partyMember.fusionGender = ally.gender;
+    partyMember.fusionLuck = ally.luck;
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["THICK_CLUB"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(2);
+  }, 20000);
+
+  it("THICK_CLUB not held by CUBONE", async() => {
+    await game.startBattle([
+      Species.PIKACHU
+    ]);
+
+    const partyMember = game.scene.getParty()[0];
+
+    const atkStat = partyMember.getStat(Stat.ATK);
+
+    // Making sure modifier is not applied without holding item
+    const atkValue = new Utils.NumberHolder(atkStat);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+
+    // Giving Eviolite to party member and testing if it applies
+    partyMember.scene.addModifier(modifierTypes.SPECIES_STAT_BOOSTER().generateType(null, ["THICK_CLUB"]).newModifier(partyMember), true);
+    partyMember.scene.applyModifiers(SpeciesStatBoosterModifier, true, partyMember, Stat.ATK, atkValue);
+
+    expect(atkValue.value / atkStat).toBe(1);
+  }, 20000);
+});