Merge branch 'beta' into localization-md

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 Thank you for taking the time to contribute, every little bit helps. This project is entirely open-source and unmonetized - community contributions are what keep it alive!
 
-Please make sure you understand everything relevant to your changes from the [Table of Contents](#-table-of-contents), and *feel free to reach out reach out in the **#dev-corner** channel on [Discord](https://discord.gg/pokerogue)*. 
+Please make sure you understand everything relevant to your changes from the [Table of Contents](#-table-of-contents), and absolutely *feel free to reach out in the **#dev-corner** channel on [Discord](https://discord.gg/pokerogue)*. 
 We are here to help and the better you understand what you're working on, the easier it will be for it to find its way into the game.
 
 ## 📄 Table of Contents
@@ -36,10 +36,6 @@ If you have the motivation and experience with Typescript/Javascript (or are wil
 [^1]: If you forget to include the `--recurse-submodules` flag when cloning initially (or do so via an alternate tool), consult [localization.md](./docs/localization.md) \
 for instructions on how to clone the `locales` submodule manually.
 
-### Linting
-
-Check out our [in-depth file](./docs/linting.md) on linting and formatting!
-
 ## 🚀 Getting Started
 
 A great way to develop an understanding of how the project works is to look at test cases (located in [the `test` folder](./test/)). 

biome.jsonc

@@ -70,7 +70,10 @@
       },
       "style": {
         "useEnumInitializers": "off", // large enums like Moves/Species would make this cumbersome
-        "useBlockStatements": "error",
+        "useBlockStatements": {
+          "level": "error",
+          "fix": "safe"
+        },
         "useConst": "error",
         "useImportType": "error",
         "noNonNullAssertion": "off", // TODO: Turn this on ASAP and fix all non-null assertions in non-test files

src/@types/attack-move-result.ts

@@ -0,0 +1,12 @@
+import type { BattlerIndex } from "#enums/battler-index";
+import type { DamageResult } from "#app/@types/damage-result";
+import type { MoveId } from "#enums/move-id";
+
+export interface AttackMoveResult {
+  move: MoveId;
+  result: DamageResult;
+  damage: number;
+  critical: boolean;
+  sourceId: number;
+  sourceBattlerIndex: BattlerIndex;
+}

src/@types/damage-result.ts

@@ -0,0 +1,21 @@
+import type { HitResult } from "#enums/hit-result";
+
+/** Union type containing all damage-dealing {@linkcode HitResult}s. */
+export type DamageResult =
+  | HitResult.EFFECTIVE
+  | HitResult.SUPER_EFFECTIVE
+  | HitResult.NOT_VERY_EFFECTIVE
+  | HitResult.ONE_HIT_KO
+  | HitResult.CONFUSION
+  | HitResult.INDIRECT_KO
+  | HitResult.INDIRECT;
+
+/** Interface containing the results of a damage calculation for a given move. */
+export interface DamageCalculationResult {
+  /** `true` if the move was cancelled (thus suppressing "No Effect" messages) */
+  cancelled: boolean;
+  /** The effectiveness of the move */
+  result: HitResult;
+  /** The damage dealt by the move */
+  damage: number;
+}

src/@types/illusion-data.ts

@@ -0,0 +1,41 @@
+import type { Gender } from "#app/data/gender";
+import type PokemonSpecies from "#app/data/pokemon-species";
+import type { Variant } from "#app/sprites/variant";
+import type { PokeballType } from "#enums/pokeball";
+import type { SpeciesId } from "#enums/species-id";
+
+/**
+ * Data pertaining to a Pokemon's Illusion.
+ */
+export interface IllusionData {
+  basePokemon: {
+    /** The actual name of the Pokemon */
+    name: string;
+    /** The actual nickname of the Pokemon */
+    nickname: string;
+    /** Whether the base pokemon is shiny or not */
+    shiny: boolean;
+    /** The shiny variant of the base pokemon */
+    variant: Variant;
+    /** Whether the fusion species of the base pokemon is shiny or not */
+    fusionShiny: boolean;
+    /** The variant of the fusion species of the base pokemon */
+    fusionVariant: Variant;
+  };
+  /** The species of the illusion */
+  species: SpeciesId;
+  /** The formIndex of the illusion */
+  formIndex: number;
+  /** The gender of the illusion */
+  gender: Gender;
+  /** The pokeball of the illusion */
+  pokeball: PokeballType;
+  /** The fusion species of the illusion if it's a fusion */
+  fusionSpecies?: PokemonSpecies;
+  /** The fusionFormIndex of the illusion */
+  fusionFormIndex?: number;
+  /** The fusionGender of the illusion if it's a fusion */
+  fusionGender?: Gender;
+  /** The level of the illusion (not used currently) */
+  level?: number;
+}

src/@types/turn-move.ts

@@ -0,0 +1,13 @@
+import type { BattlerIndex } from "#enums/battler-index";
+import type { MoveId } from "#enums/move-id";
+import type { MoveResult } from "#enums/move-result";
+import type { MoveUseMode } from "#enums/move-use-mode";
+
+/** A record of a move having been used. */
+export interface TurnMove {
+  move: MoveId;
+  targets: BattlerIndex[];
+  useMode: MoveUseMode;
+  result?: MoveResult;
+  turn?: number;
+}

src/battle-scene.ts

@@ -18,6 +18,7 @@ import {
   isNullOrUndefined,
   BooleanHolder,
   type Constructor,
+  isBetween,
 } from "#app/utils/common";
 import { deepMergeSpriteData } from "#app/utils/data";
 import type { Modifier, ModifierPredicate, TurnHeldItemTransferModifier } from "./modifier/modifier";
@@ -164,10 +165,6 @@ import { PhaseManager } from "./phase-manager";
 
 const DEBUG_RNG = false;
 
-const OPP_IVS_OVERRIDE_VALIDATED: number[] = (
-  Array.isArray(Overrides.OPP_IVS_OVERRIDE) ? Overrides.OPP_IVS_OVERRIDE : new Array(6).fill(Overrides.OPP_IVS_OVERRIDE)
-).map(iv => (Number.isNaN(iv) || iv === null || iv > 31 ? -1 : iv));
-
 export interface PokeballCounts {
   [pb: string]: number;
 }
@@ -934,9 +931,32 @@ export default class BattleScene extends SceneBase {
       nature,
       dataSource,
     );
+
     if (postProcess) {
       postProcess(pokemon);
     }
+
+    if (Overrides.IVS_OVERRIDE === null) {
+      // do nothing
+    } else if (Array.isArray(Overrides.IVS_OVERRIDE)) {
+      if (Overrides.IVS_OVERRIDE.length !== 6) {
+        throw new Error("The Player IVs override must be an array of length 6 or a number!");
+      }
+      if (Overrides.IVS_OVERRIDE.some(value => !isBetween(value, 0, 31))) {
+        throw new Error("All IVs in the player IV override must be between 0 and 31!");
+      }
+      pokemon.ivs = Overrides.IVS_OVERRIDE;
+    } else {
+      if (!isBetween(Overrides.IVS_OVERRIDE, 0, 31)) {
+        throw new Error("The Player IV override must be a value between 0 and 31!");
+      }
+      pokemon.ivs = new Array(6).fill(Overrides.IVS_OVERRIDE);
+    }
+
+    if (Overrides.NATURE_OVERRIDE !== null) {
+      pokemon.nature = Overrides.NATURE_OVERRIDE;
+    }
+
     pokemon.init();
     return pokemon;
   }
@@ -981,10 +1001,25 @@ export default class BattleScene extends SceneBase {
       postProcess(pokemon);
     }
 
-    for (let i = 0; i < pokemon.ivs.length; i++) {
+    if (Overrides.ENEMY_IVS_OVERRIDE === null) {
-      if (OPP_IVS_OVERRIDE_VALIDATED[i] > -1) {
+      // do nothing
-        pokemon.ivs[i] = OPP_IVS_OVERRIDE_VALIDATED[i];
+    } else if (Array.isArray(Overrides.ENEMY_IVS_OVERRIDE)) {
+      if (Overrides.ENEMY_IVS_OVERRIDE.length !== 6) {
+        throw new Error("The Enemy IVs override must be an array of length 6 or a number!");
       }
+      if (Overrides.ENEMY_IVS_OVERRIDE.some(value => !isBetween(value, 0, 31))) {
+        throw new Error("All IVs in the enemy IV override must be between 0 and 31!");
+      }
+      pokemon.ivs = Overrides.ENEMY_IVS_OVERRIDE;
+    } else {
+      if (!isBetween(Overrides.ENEMY_IVS_OVERRIDE, 0, 31)) {
+        throw new Error("The Enemy IV override must be a value between 0 and 31!");
+      }
+      pokemon.ivs = new Array(6).fill(Overrides.ENEMY_IVS_OVERRIDE);
+    }
+
+    if (Overrides.ENEMY_NATURE_OVERRIDE !== null) {
+      pokemon.nature = Overrides.ENEMY_NATURE_OVERRIDE;
     }
 
     pokemon.init();

src/battle.ts

@@ -17,7 +17,8 @@ import { MoneyMultiplierModifier, type PokemonHeldItemModifier } from "./modifie
 import type { PokeballType } from "#enums/pokeball";
 import { trainerConfigs } from "#app/data/trainers/trainer-config";
 import { SpeciesFormKey } from "#enums/species-form-key";
-import type { EnemyPokemon, PlayerPokemon, TurnMove } from "#app/field/pokemon";
+import type { EnemyPokemon, PlayerPokemon } from "#app/field/pokemon";
+import type { TurnMove } from "./@types/turn-move";
 import type Pokemon from "#app/field/pokemon";
 import { ArenaTagType } from "#enums/arena-tag-type";
 import { BattleSpec } from "#enums/battle-spec";

src/data/battler-tags.ts

@@ -673,7 +673,12 @@ export class ConfusedTag extends BattlerTag {
   }
 
   canAdd(pokemon: Pokemon): boolean {
-    return globalScene.arena.terrain?.terrainType !== TerrainType.MISTY || !pokemon.isGrounded();
+    const blockedByTerrain = pokemon.isGrounded() && globalScene.arena.terrain?.terrainType === TerrainType.MISTY;
+    if (blockedByTerrain) {
+      pokemon.queueStatusImmuneMessage(false, TerrainType.MISTY);
+      return false;
+    }
+    return true;
   }
 
   onAdd(pokemon: Pokemon): void {

src/data/custom-pokemon-data.ts

@@ -1,31 +0,0 @@
-import type { AbilityId } from "#enums/ability-id";
-import type { PokemonType } from "#enums/pokemon-type";
-import type { Nature } from "#enums/nature";
-
-/**
- * Data that can customize a Pokemon in non-standard ways from its Species.
- * Includes abilities, nature, changed types, etc.
- */
-export class CustomPokemonData {
-  // TODO: Change the default value for all these from -1 to something a bit more sensible
-  /**
-   * The scale at which to render this Pokemon's sprite.
-   */
-  public spriteScale = -1;
-  public ability: AbilityId | -1;
-  public passive: AbilityId | -1;
-  public nature: Nature | -1;
-  public types: PokemonType[];
-  /** Deprecated but needed for session save migration */
-  // TODO: Remove this once pre-session migration is implemented
-  public hitsRecCount: number | null = null;
-
-  constructor(data?: CustomPokemonData | Partial<CustomPokemonData>) {
-    this.spriteScale = data?.spriteScale ?? -1;
-    this.ability = data?.ability ?? -1;
-    this.passive = data?.passive ?? -1;
-    this.nature = data?.nature ?? -1;
-    this.types = data?.types ?? [];
-    this.hitsRecCount = data?.hitsRecCount ?? null;
-  }
-}

src/data/egg.ts

@@ -294,7 +294,7 @@ export class Egg {
 
   public getEggDescriptor(): string {
     if (this.isManaphyEgg()) {
-      return "Manaphy";
+      return i18next.t("egg:manaphyTier");
     }
     switch (this.tier) {
       case EggTier.RARE:

src/data/moves/move.ts

@@ -13,7 +13,8 @@ import {
   TypeBoostTag,
 } from "../battler-tags";
 import { getPokemonNameWithAffix } from "../../messages";
-import type { AttackMoveResult, TurnMove } from "../../field/pokemon";
+import type { TurnMove } from "#app/@types/turn-move";
+import type { AttackMoveResult } from "#app/@types/attack-move-result";
 import type Pokemon from "../../field/pokemon";
 import type { EnemyPokemon } from "#app/field/pokemon";
 import { PokemonMove } from "./pokemon-move";

src/data/mystery-encounters/encounters/clowning-around-encounter.ts

@@ -44,7 +44,7 @@ import { BattlerIndex } from "#enums/battler-index";
 import { MoveId } from "#enums/move-id";
 import { EncounterBattleAnim } from "#app/data/battle-anims";
 import { MoveCategory } from "#enums/MoveCategory";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import { CLASSIC_MODE_MYSTERY_ENCOUNTER_WAVES } from "#app/constants";
 import { EncounterAnim } from "#enums/encounter-anims";
 import { Challenges } from "#enums/challenges";

src/data/mystery-encounters/encounters/slumbering-snorlax-encounter.ts

@@ -29,7 +29,7 @@ import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { MysteryEncounterOptionMode } from "#enums/mystery-encounter-option-mode";
 import { BerryType } from "#enums/berry-type";
 import { Stat } from "#enums/stat";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import { randSeedInt } from "#app/utils/common";
 import { MoveUseMode } from "#enums/move-use-mode";
 

src/data/mystery-encounters/encounters/the-strong-stuff-encounter.ts

@@ -25,7 +25,7 @@ import { BattlerIndex } from "#enums/battler-index";
 import { BattlerTagType } from "#enums/battler-tag-type";
 import { BerryType } from "#enums/berry-type";
 import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import { Stat } from "#enums/stat";
 import { CLASSIC_MODE_MYSTERY_ENCOUNTER_WAVES } from "#app/constants";
 import { MoveUseMode } from "#enums/move-use-mode";

src/data/mystery-encounters/utils/encounter-phase-utils.ts

@@ -43,7 +43,7 @@ import { TrainerSlot } from "#enums/trainer-slot";
 import type PokemonSpecies from "#app/data/pokemon-species";
 import type { IEggOptions } from "#app/data/egg";
 import { Egg } from "#app/data/egg";
-import type { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import type { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import type HeldModifierConfig from "#app/@types/held-modifier-config";
 import type { Variant } from "#app/sprites/variant";
 import { StatusEffect } from "#enums/status-effect";

src/data/mystery-encounters/utils/encounter-pokemon-utils.ts

@@ -33,7 +33,7 @@ import { modifierTypes } from "#app/data/data-lists";
 import { Gender } from "#app/data/gender";
 import type { PermanentStat } from "#enums/stat";
 import { SummaryUiMode } from "#app/ui/summary-ui-handler";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import type { AbilityId } from "#enums/ability-id";
 import type { PokeballType } from "#enums/pokeball";
 import { StatusEffect } from "#enums/status-effect";

src/data/pokemon/pokemon-data.ts

@@ -0,0 +1,208 @@
+import { type BattlerTag, loadBattlerTag } from "#app/data/battler-tags";
+import type { Gender } from "#app/data/gender";
+import type { PokemonSpeciesForm } from "#app/data/pokemon-species";
+import type { TypeDamageMultiplier } from "#app/data/type";
+import { isNullOrUndefined } from "#app/utils/common";
+import type { AbilityId } from "#enums/ability-id";
+import type { BerryType } from "#enums/berry-type";
+import type { MoveId } from "#enums/move-id";
+import type { PokemonType } from "#enums/pokemon-type";
+import { PokemonMove } from "#app/data/moves/pokemon-move";
+import type { TurnMove } from "#app/@types/turn-move";
+import type { AttackMoveResult } from "#app/@types/attack-move-result";
+import type { Nature } from "#enums/nature";
+import type { IllusionData } from "#app/@types/illusion-data";
+
+/**
+ * Permanent data that can customize a Pokemon in non-standard ways from its Species.
+ * Includes abilities, nature, changed types, etc.
+ */
+export class CustomPokemonData {
+  // TODO: Change the default value for all these from -1 to something a bit more sensible
+  /**
+   * The scale at which to render this Pokemon's sprite.
+   */
+  public spriteScale = -1;
+  public ability: AbilityId | -1;
+  public passive: AbilityId | -1;
+  public nature: Nature | -1;
+  public types: PokemonType[];
+  /** Deprecated but needed for session save migration */
+  // TODO: Remove this once pre-session migration is implemented
+  public hitsRecCount: number | null = null;
+
+  constructor(data?: CustomPokemonData | Partial<CustomPokemonData>) {
+    this.spriteScale = data?.spriteScale ?? -1;
+    this.ability = data?.ability ?? -1;
+    this.passive = data?.passive ?? -1;
+    this.nature = data?.nature ?? -1;
+    this.types = data?.types ?? [];
+    this.hitsRecCount = data?.hitsRecCount ?? null;
+  }
+}
+
+/**
+ * Persistent in-battle data for a {@linkcode Pokemon}.
+ * Resets on switch or new battle.
+ */
+export class PokemonSummonData {
+  /** [Atk, Def, SpAtk, SpDef, Spd, Acc, Eva] */
+  public statStages: number[] = [0, 0, 0, 0, 0, 0, 0];
+  /**
+   * A queue of moves yet to be executed, used by charging, recharging and frenzy moves.
+   * So long as this array is nonempty, this Pokemon's corresponding `CommandPhase` will be skipped over entirely
+   * in favor of using the queued move.
+   * TODO: Clean up a lot of the code surrounding the move queue.
+   */
+  public moveQueue: TurnMove[] = [];
+  public tags: BattlerTag[] = [];
+  public abilitySuppressed = false;
+
+  // Overrides for transform.
+  // TODO: Move these into a separate class & add rage fist hit count
+  public speciesForm: PokemonSpeciesForm | null = null;
+  public fusionSpeciesForm: PokemonSpeciesForm | null = null;
+  public ability: AbilityId | undefined;
+  public passiveAbility: AbilityId | undefined;
+  public gender: Gender | undefined;
+  public fusionGender: Gender | undefined;
+  public stats: number[] = [0, 0, 0, 0, 0, 0];
+  public moveset: PokemonMove[] | null;
+
+  // If not initialized this value will not be populated from save data.
+  public types: PokemonType[] = [];
+  public addedType: PokemonType | null = null;
+
+  /** Data pertaining to this pokemon's illusion. */
+  public illusion: IllusionData | null = null;
+  public illusionBroken = false;
+
+  /** Array containing all berries eaten in the last turn; used by {@linkcode AbilityId.CUD_CHEW} */
+  public berriesEatenLast: BerryType[] = [];
+
+  /**
+   * An array of all moves this pokemon has used since entering the battle.
+   * Used for most moves and abilities that check prior move usage or copy already-used moves.
+   */
+  public moveHistory: TurnMove[] = [];
+
+  constructor(source?: PokemonSummonData | Partial<PokemonSummonData>) {
+    if (isNullOrUndefined(source)) {
+      return;
+    }
+
+    // TODO: Rework this into an actual generic function for use elsewhere
+    for (const [key, value] of Object.entries(source)) {
+      if (isNullOrUndefined(value) && this.hasOwnProperty(key)) {
+        continue;
+      }
+
+      if (key === "moveset") {
+        this.moveset = value?.map((m: any) => PokemonMove.loadMove(m));
+        continue;
+      }
+
+      if (key === "tags") {
+        // load battler tags
+        this.tags = value.map((t: BattlerTag) => loadBattlerTag(t));
+        continue;
+      }
+      this[key] = value;
+    }
+  }
+}
+
+// TODO: Merge this inside `summmonData` but exclude from save if/when a save data serializer is added
+export class PokemonTempSummonData {
+  /**
+   * The number of turns this pokemon has spent without switching out.
+   * Only currently used for positioning the battle cursor.
+   */
+  turnCount = 1;
+
+  /**
+   * The number of turns this pokemon has spent in the active position since the start of the wave
+   * without switching out.
+   * Reset on switch and new wave, but not stored in `SummonData` to avoid being written to the save file.
+
+   * Used to evaluate "first turn only" conditions such as
+   * {@linkcode MoveId.FAKE_OUT | Fake Out} and {@linkcode MoveId.FIRST_IMPRESSION | First Impression}).
+   */
+  waveTurnCount = 1;
+}
+
+/**
+ * Persistent data for a {@linkcode Pokemon}.
+ * Resets at the start of a new battle (but not on switch).
+ */
+export class PokemonBattleData {
+  /** Counter tracking direct hits this Pokemon has received during this battle; used for {@linkcode MoveId.RAGE_FIST} */
+  public hitCount = 0;
+  /** Whether this Pokemon has eaten a berry this battle; used for {@linkcode MoveId.BELCH} */
+  public hasEatenBerry = false;
+  /** Array containing all berries eaten and not yet recovered during this current battle; used by {@linkcode AbilityId.HARVEST} */
+  public berriesEaten: BerryType[] = [];
+
+  constructor(source?: PokemonBattleData | Partial<PokemonBattleData>) {
+    if (!isNullOrUndefined(source)) {
+      this.hitCount = source.hitCount ?? 0;
+      this.hasEatenBerry = source.hasEatenBerry ?? false;
+      this.berriesEaten = source.berriesEaten ?? [];
+    }
+  }
+}
+
+/**
+ * Temporary data for a {@linkcode Pokemon}.
+ * Resets on new wave/battle start (but not on switch).
+ */
+export class PokemonWaveData {
+  /** Whether the pokemon has endured due to a {@linkcode BattlerTagType.ENDURE_TOKEN} */
+  public endured = false;
+  /**
+   * A set of all the abilities this {@linkcode Pokemon} has used in this wave.
+   * Used to track once per battle conditions, as well as (hopefully) by the updated AI for move effectiveness.
+   */
+  public abilitiesApplied: Set<AbilityId> = new Set<AbilityId>();
+  /** Whether the pokemon's ability has been revealed or not */
+  public abilityRevealed = false;
+}
+
+/**
+ * Temporary data for a {@linkcode Pokemon}.
+ * Resets at the start of a new turn, as well as on switch.
+ */
+export class PokemonTurnData {
+  public acted = false;
+  /** How many times the current move should hit the target(s) */
+  public hitCount = 0;
+  /**
+   * - `-1` = Calculate how many hits are left
+   * - `0` = Move is finished
+   */
+  public hitsLeft = -1;
+  public totalDamageDealt = 0;
+  public singleHitDamageDealt = 0;
+  public damageTaken = 0;
+  public attacksReceived: AttackMoveResult[] = [];
+  public order: number;
+  public statStagesIncreased = false;
+  public statStagesDecreased = false;
+  public moveEffectiveness: TypeDamageMultiplier | null = null;
+  public combiningPledge?: MoveId;
+  public switchedInThisTurn = false;
+  public failedRunAway = false;
+  public joinedRound = false;
+  /**
+   * The amount of times this Pokemon has acted again and used a move in the current turn.
+   * Used to make sure multi-hits occur properly when the user is
+   * forced to act again in the same turn, and **must be incremented** by any effects that grant extra actions.
+   */
+  public extraTurns = 0;
+  /**
+   * All berries eaten by this pokemon in this turn.
+   * Saved into {@linkcode PokemonSummonData | SummonData} by {@linkcode AbilityId.CUD_CHEW} on turn end.
+   * @see {@linkcode PokemonSummonData.berriesEatenLast}
+   */
+  public berriesEaten: BerryType[] = [];
+}

src/data/terrain.ts

@@ -3,6 +3,7 @@ import type Move from "./moves/move";
 import { PokemonType } from "#enums/pokemon-type";
 import type { BattlerIndex } from "#enums/battler-index";
 import i18next from "i18next";
+import { getPokemonNameWithAffix } from "#app/messages";
 
 export enum TerrainType {
   NONE,
@@ -96,3 +97,76 @@ export function getTerrainColor(terrainType: TerrainType): [number, number, numb
 
   return [0, 0, 0];
 }
+
+/**
+ * Return the message associated with a terrain effect starting.
+ * @param terrainType - The {@linkcode TerrainType} starting.
+ * @returns A string containing the appropriate terrain start text.
+ */
+export function getTerrainStartMessage(terrainType: TerrainType): string {
+  switch (terrainType) {
+    case TerrainType.MISTY:
+      return i18next.t("terrain:mistyStartMessage");
+    case TerrainType.ELECTRIC:
+      return i18next.t("terrain:electricStartMessage");
+    case TerrainType.GRASSY:
+      return i18next.t("terrain:grassyStartMessage");
+    case TerrainType.PSYCHIC:
+      return i18next.t("terrain:psychicStartMessage");
+    case TerrainType.NONE:
+    default:
+      terrainType satisfies TerrainType.NONE;
+      console.warn(`${terrainType} unexpectedly provided as terrain type to getTerrainStartMessage!`);
+      return "";
+  }
+}
+
+/**
+ * Return the message associated with a terrain effect ceasing to exist.
+ * @param terrainType - The {@linkcode TerrainType} being cleared.
+ * @returns A string containing the appropriate terrain clear text.
+ */
+export function getTerrainClearMessage(terrainType: TerrainType): string {
+  switch (terrainType) {
+    case TerrainType.MISTY:
+      return i18next.t("terrain:mistyClearMessage");
+    case TerrainType.ELECTRIC:
+      return i18next.t("terrain:electricClearMessage");
+    case TerrainType.GRASSY:
+      return i18next.t("terrain:grassyClearMessage");
+    case TerrainType.PSYCHIC:
+      return i18next.t("terrain:psychicClearMessage");
+    case TerrainType.NONE:
+    default:
+      terrainType satisfies TerrainType.NONE;
+      console.warn(`${terrainType} unexpectedly provided as terrain type to getTerrainClearMessage!`);
+      return "";
+  }
+}
+
+/**
+ * Return the message associated with a terrain-induced move/effect blockage.
+ * @param pokemon - The {@linkcode Pokemon} being protected.
+ * @param terrainType - The {@linkcode TerrainType} in question
+ * @returns A string containing the appropriate terrain block text.
+ */
+export function getTerrainBlockMessage(pokemon: Pokemon, terrainType: TerrainType): string {
+  switch (terrainType) {
+    case TerrainType.MISTY:
+      return i18next.t("terrain:mistyBlockMessage", {
+        pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
+      });
+    case TerrainType.ELECTRIC:
+    case TerrainType.GRASSY:
+    case TerrainType.PSYCHIC:
+      return i18next.t("terrain:defaultBlockMessage", {
+        pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
+        terrainName: getTerrainName(terrainType),
+      });
+    case TerrainType.NONE:
+    default:
+      terrainType satisfies TerrainType.NONE;
+      console.warn(`${terrainType} unexpectedly provided as terrain type to getTerrainBlockMessage!`);
+      return "";
+  }
+}

src/data/weather.ts

@@ -5,7 +5,6 @@ import type Pokemon from "../field/pokemon";
 import { PokemonType } from "#enums/pokemon-type";
 import type Move from "./moves/move";
 import { randSeedInt } from "#app/utils/common";
-import { TerrainType, getTerrainName } from "./terrain";
 import i18next from "i18next";
 import { globalScene } from "#app/global-scene";
 import type { Arena } from "#app/field/arena";
@@ -235,50 +234,6 @@ export function getWeatherBlockMessage(weatherType: WeatherType): string {
   return i18next.t("weather:defaultEffectMessage");
 }
 
-export function getTerrainStartMessage(terrainType: TerrainType): string | null {
-  switch (terrainType) {
-    case TerrainType.MISTY:
-      return i18next.t("terrain:mistyStartMessage");
-    case TerrainType.ELECTRIC:
-      return i18next.t("terrain:electricStartMessage");
-    case TerrainType.GRASSY:
-      return i18next.t("terrain:grassyStartMessage");
-    case TerrainType.PSYCHIC:
-      return i18next.t("terrain:psychicStartMessage");
-    default:
-      console.warn("getTerrainStartMessage not defined. Using default null");
-      return null;
-  }
-}
-
-export function getTerrainClearMessage(terrainType: TerrainType): string | null {
-  switch (terrainType) {
-    case TerrainType.MISTY:
-      return i18next.t("terrain:mistyClearMessage");
-    case TerrainType.ELECTRIC:
-      return i18next.t("terrain:electricClearMessage");
-    case TerrainType.GRASSY:
-      return i18next.t("terrain:grassyClearMessage");
-    case TerrainType.PSYCHIC:
-      return i18next.t("terrain:psychicClearMessage");
-    default:
-      console.warn("getTerrainClearMessage not defined. Using default null");
-      return null;
-  }
-}
-
-export function getTerrainBlockMessage(pokemon: Pokemon, terrainType: TerrainType): string {
-  if (terrainType === TerrainType.MISTY) {
-    return i18next.t("terrain:mistyBlockMessage", {
-      pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
-    });
-  }
-  return i18next.t("terrain:defaultBlockMessage", {
-    pokemonNameWithAffix: getPokemonNameWithAffix(pokemon),
-    terrainName: getTerrainName(terrainType),
-  });
-}
-
 export interface WeatherPoolEntry {
   weatherType: WeatherType;
   weight: number;

src/field/arena.ts

@@ -5,8 +5,6 @@ import { randSeedInt, NumberHolder, isNullOrUndefined, type Constructor } from "
 import type PokemonSpecies from "#app/data/pokemon-species";
 import { getPokemonSpecies } from "#app/utils/pokemon-utils";
 import {
-  getTerrainClearMessage,
-  getTerrainStartMessage,
   getWeatherClearMessage,
   getWeatherStartMessage,
   getLegendaryWeatherContinuesMessage,
@@ -19,7 +17,7 @@ import type { ArenaTag } from "#app/data/arena-tag";
 import { ArenaTrapTag, getArenaTag } from "#app/data/arena-tag";
 import { ArenaTagSide } from "#enums/arena-tag-side";
 import type { BattlerIndex } from "#enums/battler-index";
-import { Terrain, TerrainType } from "#app/data/terrain";
+import { Terrain, TerrainType, getTerrainClearMessage, getTerrainStartMessage } from "#app/data/terrain";
 import { applyAbAttrs } from "#app/data/abilities/apply-ab-attrs";
 import type Pokemon from "#app/field/pokemon";
 import Overrides from "#app/overrides";
@@ -445,9 +443,9 @@ export class Arena {
           CommonAnim.MISTY_TERRAIN + (terrain - 1),
         );
       }
-      globalScene.phaseManager.queueMessage(getTerrainStartMessage(terrain)!); // TODO: is this bang correct?
+      globalScene.phaseManager.queueMessage(getTerrainStartMessage(terrain));
     } else {
-      globalScene.phaseManager.queueMessage(getTerrainClearMessage(oldTerrainType)!); // TODO: is this bang correct?
+      globalScene.phaseManager.queueMessage(getTerrainClearMessage(oldTerrainType));
     }
 
     globalScene

src/field/damage-number-handler.ts

@@ -1,5 +1,5 @@
 import { TextStyle, addTextObject } from "../ui/text";
-import type { DamageResult } from "./pokemon";
+import type { DamageResult } from "../@types/damage-result";
 import type Pokemon from "./pokemon";
 import { HitResult } from "#enums/hit-result";
 import { formatStat, fixedInt } from "#app/utils/common";

src/field/pokemon.ts

@@ -100,7 +100,6 @@ import {
   TarShotTag,
   AutotomizedTag,
   PowerTrickTag,
-  loadBattlerTag,
   type GrudgeTag,
 } from "../data/battler-tags";
 import { BattlerTagLapseType } from "#enums/battler-tag-lapse-type";
@@ -151,7 +150,14 @@ import { getPokemonNameWithAffix } from "#app/messages";
 import { Challenges } from "#enums/challenges";
 import { PokemonAnimType } from "#enums/pokemon-anim-type";
 import { PLAYER_PARTY_MAX_SIZE } from "#app/constants";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import {
+  CustomPokemonData,
+  PokemonBattleData,
+  PokemonSummonData,
+  PokemonTempSummonData,
+  PokemonTurnData,
+  PokemonWaveData,
+} from "#app/data/pokemon/pokemon-data";
 import { SwitchType } from "#enums/switch-type";
 import { SpeciesFormKey } from "#enums/species-form-key";
 import { getStatusEffectOverlapText } from "#app/data/status-effect";
@@ -169,12 +175,15 @@ import { timedEventManager } from "#app/global-event-manager";
 import { loadMoveAnimations } from "#app/sprites/pokemon-asset-loader";
 import { isVirtual, isIgnorePP, MoveUseMode } from "#enums/move-use-mode";
 import { FieldPosition } from "#enums/field-position";
-import { LearnMoveSituation } from "#enums/learn-move-situation";
 import { HitResult } from "#enums/hit-result";
 import { AiType } from "#enums/ai-type";
-import type { MoveResult } from "#enums/move-result";
 import { PokemonMove } from "#app/data/moves/pokemon-move";
+import type { IllusionData } from "#app/@types/illusion-data";
+import type { TurnMove } from "#app/@types/turn-move";
+import type { DamageCalculationResult, DamageResult } from "#app/@types/damage-result";
 import type { AbAttrMap, AbAttrString, TypeMultiplierAbAttrParams } from "#app/@types/ability-types";
+import { getTerrainBlockMessage } from "#app/data/terrain";
+import { LearnMoveSituation } from "#enums/learn-move-situation";
 
 /** Base typeclass for damage parameter methods, used for DRY */
 type damageParams = {
@@ -4654,16 +4663,37 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     );
   }
 
-  queueImmuneMessage(quiet: boolean, effect?: StatusEffect): void {
+  /**
-    if (!effect || quiet) {
+   * Display an immunity message for a failed status application.
+   * @param quiet - Whether to suppress message and return early
+   * @param reason - The reason for the status application failure -
+   * can be "overlap" (already has same status), "other" (generic fail message)
+   * or a {@linkcode TerrainType} for terrain-based blockages.
+   * Defaults to "other".
+   */
+  queueStatusImmuneMessage(
+    quiet: boolean,
+    reason: "overlap" | "other" | Exclude<TerrainType, TerrainType.NONE> = "other",
+  ): void {
+    if (quiet) {
       return;
     }
-    const message =
+
-      effect && this.status?.effect === effect
+    let message: string;
-        ? getStatusEffectOverlapText(effect ?? StatusEffect.NONE, getPokemonNameWithAffix(this))
+    if (reason === "overlap") {
-        : i18next.t("abilityTriggers:moveImmunity", {
+      // "XYZ is already XXX!"
+      message = getStatusEffectOverlapText(this.status?.effect ?? StatusEffect.NONE, getPokemonNameWithAffix(this));
+    } else if (typeof reason === "number") {
+      // "XYZ was protected by the XXX terrain!" /
+      // "XYZ surrounds itself with a protective mist!"
+      message = getTerrainBlockMessage(this, reason);
+    } else {
+      // "It doesn't affect XXX!"
+      message = i18next.t("abilityTriggers:moveImmunity", {
         pokemonNameWithAffix: getPokemonNameWithAffix(this),
       });
+    }
+
     globalScene.phaseManager.queueMessage(message);
   }
 
@@ -4685,11 +4715,11 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
   ): boolean {
     if (effect !== StatusEffect.FAINT) {
       if (overrideStatus ? this.status?.effect === effect : this.status) {
-        this.queueImmuneMessage(quiet, effect);
+        this.queueStatusImmuneMessage(quiet, overrideStatus ? "overlap" : "other"); // having different status displays generic fail message
         return false;
       }
       if (this.isGrounded() && !ignoreField && globalScene.arena.terrain?.terrainType === TerrainType.MISTY) {
-        this.queueImmuneMessage(quiet, effect);
+        this.queueStatusImmuneMessage(quiet, TerrainType.MISTY);
         return false;
       }
     }
@@ -4726,7 +4756,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
 
         if (this.isOfType(PokemonType.POISON) || this.isOfType(PokemonType.STEEL)) {
           if (poisonImmunity.includes(true)) {
-            this.queueImmuneMessage(quiet, effect);
+            this.queueStatusImmuneMessage(quiet);
             return false;
           }
         }
@@ -4734,13 +4764,13 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
       }
       case StatusEffect.PARALYSIS:
         if (this.isOfType(PokemonType.ELECTRIC)) {
-          this.queueImmuneMessage(quiet, effect);
+          this.queueStatusImmuneMessage(quiet);
           return false;
         }
         break;
       case StatusEffect.SLEEP:
         if (this.isGrounded() && globalScene.arena.terrain?.terrainType === TerrainType.ELECTRIC) {
-          this.queueImmuneMessage(quiet, effect);
+          this.queueStatusImmuneMessage(quiet, TerrainType.ELECTRIC);
           return false;
         }
         break;
@@ -4751,13 +4781,13 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
             globalScene?.arena?.weather?.weatherType &&
             [WeatherType.SUNNY, WeatherType.HARSH_SUN].includes(globalScene.arena.weather.weatherType))
         ) {
-          this.queueImmuneMessage(quiet, effect);
+          this.queueStatusImmuneMessage(quiet);
           return false;
         }
         break;
       case StatusEffect.BURN:
         if (this.isOfType(PokemonType.FIRE)) {
-          this.queueImmuneMessage(quiet, effect);
+          this.queueStatusImmuneMessage(quiet);
           return false;
         }
         break;
@@ -6790,241 +6820,3 @@ export class EnemyPokemon extends Pokemon {
     this.battleInfo.toggleFlyout(visible);
   }
 }
-
-/**
- * Illusion property
- */
-interface IllusionData {
-  basePokemon: {
-    /** The actual name of the Pokemon */
-    name: string;
-    /** The actual nickname of the Pokemon */
-    nickname: string;
-    /** Whether the base pokemon is shiny or not */
-    shiny: boolean;
-    /** The shiny variant of the base pokemon */
-    variant: Variant;
-    /** Whether the fusion species of the base pokemon is shiny or not */
-    fusionShiny: boolean;
-    /** The variant of the fusion species of the base pokemon */
-    fusionVariant: Variant;
-  };
-  /** The species of the illusion */
-  species: SpeciesId;
-  /** The formIndex of the illusion */
-  formIndex: number;
-  /** The gender of the illusion */
-  gender: Gender;
-  /** The pokeball of the illusion */
-  pokeball: PokeballType;
-  /** The fusion species of the illusion if it's a fusion */
-  fusionSpecies?: PokemonSpecies;
-  /** The fusionFormIndex of the illusion */
-  fusionFormIndex?: number;
-  /** The fusionGender of the illusion if it's a fusion */
-  fusionGender?: Gender;
-  /** The level of the illusion (not used currently) */
-  level?: number;
-}
-
-export interface TurnMove {
-  move: MoveId;
-  targets: BattlerIndex[];
-  useMode: MoveUseMode;
-  result?: MoveResult;
-  turn?: number;
-}
-
-export interface AttackMoveResult {
-  move: MoveId;
-  result: DamageResult;
-  damage: number;
-  critical: boolean;
-  sourceId: number;
-  sourceBattlerIndex: BattlerIndex;
-}
-
-/**
- * Persistent in-battle data for a {@linkcode Pokemon}.
- * Resets on switch or new battle.
- */
-export class PokemonSummonData {
-  /** [Atk, Def, SpAtk, SpDef, Spd, Acc, Eva] */
-  public statStages: number[] = [0, 0, 0, 0, 0, 0, 0];
-  /**
-   * A queue of moves yet to be executed, used by charging, recharging and frenzy moves.
-   * So long as this array is nonempty, this Pokemon's corresponding `CommandPhase` will be skipped over entirely
-   * in favor of using the queued move.
-   * TODO: Clean up a lot of the code surrounding the move queue.
-   */
-  public moveQueue: TurnMove[] = [];
-  public tags: BattlerTag[] = [];
-  public abilitySuppressed = false;
-
-  // Overrides for transform.
-  // TODO: Move these into a separate class & add rage fist hit count
-  public speciesForm: PokemonSpeciesForm | null = null;
-  public fusionSpeciesForm: PokemonSpeciesForm | null = null;
-  public ability: AbilityId | undefined;
-  public passiveAbility: AbilityId | undefined;
-  public gender: Gender | undefined;
-  public fusionGender: Gender | undefined;
-  public stats: number[] = [0, 0, 0, 0, 0, 0];
-  public moveset: PokemonMove[] | null;
-
-  // If not initialized this value will not be populated from save data.
-  public types: PokemonType[] = [];
-  public addedType: PokemonType | null = null;
-
-  /** Data pertaining to this pokemon's illusion. */
-  public illusion: IllusionData | null = null;
-  public illusionBroken = false;
-
-  /** Array containing all berries eaten in the last turn; used by {@linkcode AbilityId.CUD_CHEW} */
-  public berriesEatenLast: BerryType[] = [];
-
-  /**
-   * An array of all moves this pokemon has used since entering the battle.
-   * Used for most moves and abilities that check prior move usage or copy already-used moves.
-   */
-  public moveHistory: TurnMove[] = [];
-
-  constructor(source?: PokemonSummonData | Partial<PokemonSummonData>) {
-    if (isNullOrUndefined(source)) {
-      return;
-    }
-
-    // TODO: Rework this into an actual generic function for use elsewhere
-    for (const [key, value] of Object.entries(source)) {
-      if (isNullOrUndefined(value) && this.hasOwnProperty(key)) {
-        continue;
-      }
-
-      if (key === "moveset") {
-        this.moveset = value?.map((m: any) => PokemonMove.loadMove(m));
-        continue;
-      }
-
-      if (key === "tags") {
-        // load battler tags
-        this.tags = value.map((t: BattlerTag) => loadBattlerTag(t));
-        continue;
-      }
-      this[key] = value;
-    }
-  }
-}
-
-// TODO: Merge this inside `summmonData` but exclude from save if/when a save data serializer is added
-export class PokemonTempSummonData {
-  /**
-   * The number of turns this pokemon has spent without switching out.
-   * Only currently used for positioning the battle cursor.
-   */
-  turnCount = 1;
-
-  /**
-   * The number of turns this pokemon has spent in the active position since the start of the wave
-   * without switching out.
-   * Reset on switch and new wave, but not stored in `SummonData` to avoid being written to the save file.
-
-   * Used to evaluate "first turn only" conditions such as
-   * {@linkcode MoveId.FAKE_OUT | Fake Out} and {@linkcode MoveId.FIRST_IMPRESSION | First Impression}).
-   */
-  waveTurnCount = 1;
-}
-
-/**
- * Persistent data for a {@linkcode Pokemon}.
- * Resets at the start of a new battle (but not on switch).
- */
-export class PokemonBattleData {
-  /** Counter tracking direct hits this Pokemon has received during this battle; used for {@linkcode MoveId.RAGE_FIST} */
-  public hitCount = 0;
-  /** Whether this Pokemon has eaten a berry this battle; used for {@linkcode MoveId.BELCH} */
-  public hasEatenBerry = false;
-  /** Array containing all berries eaten and not yet recovered during this current battle; used by {@linkcode AbilityId.HARVEST} */
-  public berriesEaten: BerryType[] = [];
-
-  constructor(source?: PokemonBattleData | Partial<PokemonBattleData>) {
-    if (!isNullOrUndefined(source)) {
-      this.hitCount = source.hitCount ?? 0;
-      this.hasEatenBerry = source.hasEatenBerry ?? false;
-      this.berriesEaten = source.berriesEaten ?? [];
-    }
-  }
-}
-
-/**
- * Temporary data for a {@linkcode Pokemon}.
- * Resets on new wave/battle start (but not on switch).
- */
-export class PokemonWaveData {
-  /** Whether the pokemon has endured due to a {@linkcode BattlerTagType.ENDURE_TOKEN} */
-  public endured = false;
-  /**
-   * A set of all the abilities this {@linkcode Pokemon} has used in this wave.
-   * Used to track once per battle conditions, as well as (hopefully) by the updated AI for move effectiveness.
-   */
-  public abilitiesApplied: Set<AbilityId> = new Set<AbilityId>();
-  /** Whether the pokemon's ability has been revealed or not */
-  public abilityRevealed = false;
-}
-
-/**
- * Temporary data for a {@linkcode Pokemon}.
- * Resets at the start of a new turn, as well as on switch.
- */
-export class PokemonTurnData {
-  public acted = false;
-  /** How many times the current move should hit the target(s) */
-  public hitCount = 0;
-  /**
-   * - `-1` = Calculate how many hits are left
-   * - `0` = Move is finished
-   */
-  public hitsLeft = -1;
-  public totalDamageDealt = 0;
-  public singleHitDamageDealt = 0;
-  public damageTaken = 0;
-  public attacksReceived: AttackMoveResult[] = [];
-  public order: number;
-  public statStagesIncreased = false;
-  public statStagesDecreased = false;
-  public moveEffectiveness: TypeDamageMultiplier | null = null;
-  public combiningPledge?: MoveId;
-  public switchedInThisTurn = false;
-  public failedRunAway = false;
-  public joinedRound = false;
-  /**
-   * The amount of times this Pokemon has acted again and used a move in the current turn.
-   * Used to make sure multi-hits occur properly when the user is
-   * forced to act again in the same turn, and **must be incremented** by any effects that grant extra actions.
-   */
-  public extraTurns = 0;
-  /**
-   * All berries eaten by this pokemon in this turn.
-   * Saved into {@linkcode PokemonSummonData | SummonData} by {@linkcode AbilityId.CUD_CHEW} on turn end.
-   * @see {@linkcode PokemonSummonData.berriesEatenLast}
-   */
-  public berriesEaten: BerryType[] = [];
-}
-
-export type DamageResult =
-  | HitResult.EFFECTIVE
-  | HitResult.SUPER_EFFECTIVE
-  | HitResult.NOT_VERY_EFFECTIVE
-  | HitResult.ONE_HIT_KO
-  | HitResult.CONFUSION
-  | HitResult.INDIRECT_KO
-  | HitResult.INDIRECT;
-
-/** Interface containing the results of a damage calculation for a given move */
-export interface DamageCalculationResult {
-  /** `true` if the move was cancelled (thus suppressing "No Effect" messages) */
-  cancelled: boolean;
-  /** The effectiveness of the move */
-  result: HitResult;
-  /** The damage dealt by the move */
-  damage: number;
-}

src/overrides.ts

@@ -1,18 +1,18 @@
 import { type PokeballCounts } from "#app/battle-scene";
 import { EvolutionItem } from "#app/data/balance/pokemon-evolutions";
 import { Gender } from "#app/data/gender";
-import { FormChangeItem } from "#enums/form-change-item";
 import { type ModifierOverride } from "#app/modifier/modifier-type";
 import { Variant } from "#app/sprites/variant";
-import { Unlockables } from "#enums/unlockables";
 import { AbilityId } from "#enums/ability-id";
 import { BattleType } from "#enums/battle-type";
 import { BerryType } from "#enums/berry-type";
 import { BiomeId } from "#enums/biome-id";
 import { EggTier } from "#enums/egg-type";
+import { FormChangeItem } from "#enums/form-change-item";
 import { MoveId } from "#enums/move-id";
 import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
+import { Nature } from "#enums/nature";
 import { PokeballType } from "#enums/pokeball";
 import { PokemonType } from "#enums/pokemon-type";
 import { SpeciesId } from "#enums/species-id";
@@ -20,6 +20,7 @@ import { Stat } from "#enums/stat";
 import { StatusEffect } from "#enums/status-effect";
 import { TimeOfDay } from "#enums/time-of-day";
 import { TrainerType } from "#enums/trainer-type";
+import { Unlockables } from "#enums/unlockables";
 import { VariantTier } from "#enums/variant-tier";
 import { WeatherType } from "#enums/weather-type";
 
@@ -159,10 +160,20 @@ class DefaultOverrides {
   readonly MOVESET_OVERRIDE: MoveId | Array<MoveId> = [];
   readonly SHINY_OVERRIDE: boolean | null = null;
   readonly VARIANT_OVERRIDE: Variant | null = null;
+  /**
+   * Overrides the IVs of player pokemon. Values must never be outside the range `0` to `31`!
+   * - If set to a number between `0` and `31`, set all IVs of all player pokemon to that number.
+   * - If set to an array, set the IVs of all player pokemon to that array. Array length must be exactly `6`!
+   * - If set to `null`, disable the override.
+   */
+  readonly IVS_OVERRIDE: number | number[] | null = null;
+  /** Override the nature of all player pokemon to the specified nature. Disabled if `null`. */
+  readonly NATURE_OVERRIDE: Nature | null = null;
 
   // --------------------------
   // OPPONENT / ENEMY OVERRIDES
   // --------------------------
+  // TODO: rename `OPP_` to `ENEMY_`
   readonly OPP_SPECIES_OVERRIDE: SpeciesId | number = 0;
   /**
    * This will make all opponents fused Pokemon
@@ -181,7 +192,15 @@ class DefaultOverrides {
   readonly OPP_MOVESET_OVERRIDE: MoveId | Array<MoveId> = [];
   readonly OPP_SHINY_OVERRIDE: boolean | null = null;
   readonly OPP_VARIANT_OVERRIDE: Variant | null = null;
-  readonly OPP_IVS_OVERRIDE: number | number[] = [];
+  /**
+   * Overrides the IVs of enemy pokemon. Values must never be outside the range `0` to `31`!
+   * - If set to a number between `0` and `31`, set all IVs of all enemy pokemon to that number.
+   * - If set to an array, set the IVs of all enemy pokemon to that array. Array length must be exactly `6`!
+   * - If set to `null`, disable the override.
+   */
+  readonly ENEMY_IVS_OVERRIDE: number | number[] | null = null;
+  /** Override the nature of all enemy pokemon to the specified nature. Disabled if `null`. */
+  readonly ENEMY_NATURE_OVERRIDE: Nature | null = null;
   readonly OPP_FORM_OVERRIDES: Partial<Record<SpeciesId, number>> = {};
   /**
    * Override to give the enemy Pokemon a given amount of health segments

src/phases/command-phase.ts

@@ -11,7 +11,8 @@ import { BattlerTagType } from "#app/enums/battler-tag-type";
 import { BiomeId } from "#enums/biome-id";
 import { MoveId } from "#enums/move-id";
 import { PokeballType } from "#enums/pokeball";
-import type { PlayerPokemon, TurnMove } from "#app/field/pokemon";
+import type { PlayerPokemon } from "#app/field/pokemon";
+import type { TurnMove } from "#app/@types/turn-move";
 import { FieldPosition } from "#enums/field-position";
 import { getPokemonNameWithAffix } from "#app/messages";
 import { Command } from "#enums/command";

src/phases/damage-anim-phase.ts

@@ -1,7 +1,7 @@
 import { globalScene } from "#app/global-scene";
 import type { BattlerIndex } from "#enums/battler-index";
 import { BattleSpec } from "#enums/battle-spec";
-import type { DamageResult } from "#app/field/pokemon";
+import type { DamageResult } from "#app/@types/damage-result";
 import { HitResult } from "#enums/hit-result";
 import { fixedInt } from "#app/utils/common";
 import { PokemonPhase } from "#app/phases/pokemon-phase";

src/phases/move-effect-phase.ts

@@ -21,7 +21,8 @@ import { MoveTarget } from "#enums/MoveTarget";
 import { MoveCategory } from "#enums/MoveCategory";
 import { SpeciesFormChangePostMoveTrigger } from "#app/data/pokemon-forms/form-change-triggers";
 import { PokemonType } from "#enums/pokemon-type";
-import type { DamageResult, TurnMove } from "#app/field/pokemon";
+import type { DamageResult } from "#app/@types/damage-result";
+import type { TurnMove } from "#app/@types/turn-move";
 import { PokemonMove } from "#app/data/moves/pokemon-move";
 import type Pokemon from "#app/field/pokemon";
 import { MoveResult } from "#enums/move-result";

src/phases/move-phase.ts

@@ -11,7 +11,7 @@ import { MoveFlags } from "#enums/MoveFlags";
 import { SpeciesFormChangePreMoveTrigger } from "#app/data/pokemon-forms/form-change-triggers";
 import { getStatusEffectActivationText, getStatusEffectHealText } from "#app/data/status-effect";
 import { PokemonType } from "#enums/pokemon-type";
-import { getTerrainBlockMessage, getWeatherBlockMessage } from "#app/data/weather";
+import { getWeatherBlockMessage } from "#app/data/weather";
 import { MoveUsedEvent } from "#app/events/battle-scene";
 import type { PokemonMove } from "#app/data/moves/pokemon-move";
 import type Pokemon from "#app/field/pokemon";
@@ -26,6 +26,7 @@ import { BattlerTagType } from "#enums/battler-tag-type";
 import { MoveId } from "#enums/move-id";
 import { StatusEffect } from "#enums/status-effect";
 import i18next from "i18next";
+import { getTerrainBlockMessage } from "#app/data/terrain";
 import { isVirtual, isIgnorePP, isReflected, MoveUseMode, isIgnoreStatus } from "#enums/move-use-mode";
 import { frenzyMissFunc } from "#app/data/moves/move-utils";
 

src/system/pokemon-data.ts

@@ -6,14 +6,14 @@ import { PokeballType } from "#enums/pokeball";
 import { getPokemonSpeciesForm } from "#app/data/pokemon-species";
 import { getPokemonSpecies } from "#app/utils/pokemon-utils";
 import { Status } from "../data/status-effect";
-import Pokemon, { EnemyPokemon, PokemonBattleData, PokemonSummonData } from "../field/pokemon";
+import Pokemon, { EnemyPokemon } from "../field/pokemon";
 import { PokemonMove } from "#app/data/moves/pokemon-move";
 import { TrainerSlot } from "#enums/trainer-slot";
 import type { Variant } from "#app/sprites/variant";
 import type { BiomeId } from "#enums/biome-id";
 import type { MoveId } from "#enums/move-id";
 import type { SpeciesId } from "#enums/species-id";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData, PokemonBattleData, PokemonSummonData } from "#app/data/pokemon/pokemon-data";
 import type { PokemonType } from "#enums/pokemon-type";
 
 export default class PokemonData {

src/system/version_migration/versions/v1_0_4.ts

@@ -4,7 +4,7 @@ import { defaultStarterSpecies } from "#app/constants";
 import { AbilityAttr } from "#enums/ability-attr";
 import { DexAttr } from "#enums/dex-attr";
 import { allSpecies } from "#app/data/data-lists";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import { isNullOrUndefined } from "#app/utils/common";
 import type { SystemSaveMigrator } from "#app/@types/SystemSaveMigrator";
 import type { SettingsSaveMigrator } from "#app/@types/SettingsSaveMigrator";

src/system/version_migration/versions/v1_10_0.ts

@@ -1,6 +1,6 @@
 import type { SessionSaveMigrator } from "#app/@types/SessionSaveMigrator";
 import type { BattlerIndex } from "#enums/battler-index";
-import type { TurnMove } from "#app/field/pokemon";
+import type { TurnMove } from "#app/@types/turn-move";
 import type { MoveResult } from "#enums/move-result";
 import type { SessionSaveData } from "#app/system/game-data";
 import { MoveUseMode } from "#enums/move-use-mode";

src/ui/party-ui-handler.ts

@@ -1,4 +1,5 @@
-import type { PlayerPokemon, TurnMove } from "#app/field/pokemon";
+import type { PlayerPokemon } from "#app/field/pokemon";
+import type { TurnMove } from "#app/@types/turn-move";
 import type { PokemonMove } from "#app/data/moves/pokemon-move";
 import type Pokemon from "#app/field/pokemon";
 import { MoveResult } from "#enums/move-result";

test/abilities/gorilla_tactics.test.ts

@@ -28,8 +28,10 @@ describe("Abilities - Gorilla Tactics", () => {
     game = new GameManager(phaserGame);
     game.override
       .battleStyle("single")
+      .criticalHits(false)
       .enemyAbility(AbilityId.BALL_FETCH)
       .enemySpecies(SpeciesId.MAGIKARP)
+      .enemyMoveset(MoveId.SPLASH)
       .enemyLevel(30)
       .moveset([MoveId.SPLASH, MoveId.TACKLE, MoveId.GROWL, MoveId.METRONOME])
       .ability(AbilityId.GORILLA_TACTICS);
@@ -42,7 +44,6 @@ describe("Abilities - Gorilla Tactics", () => {
     const initialAtkStat = darmanitan.getStat(Stat.ATK);
 
     game.move.select(MoveId.SPLASH);
-    await game.move.forceEnemyMove(MoveId.SPLASH);
     await game.toEndOfTurn();
 
     expect(darmanitan.getStat(Stat.ATK, false)).toBeCloseTo(initialAtkStat * 1.5);
@@ -59,7 +60,6 @@ describe("Abilities - Gorilla Tactics", () => {
 
     // First turn, lock move to Growl
     game.move.select(MoveId.GROWL);
-    await game.move.forceEnemyMove(MoveId.SPLASH);
     await game.toNextTurn();
 
     // Second turn, Growl is interrupted by Disable
@@ -72,7 +72,7 @@ describe("Abilities - Gorilla Tactics", () => {
 
     // Third turn, Struggle is used
     game.move.select(MoveId.TACKLE);
-    await game.move.forceEnemyMove(MoveId.SPLASH); //prevent protect from being used by the enemy
+    await game.move.forceEnemyMove(MoveId.SPLASH); // prevent disable from being used by the enemy
     await game.setTurnOrder([BattlerIndex.PLAYER, BattlerIndex.ENEMY]);
     await game.phaseInterceptor.to("MoveEndPhase");
 
@@ -106,11 +106,13 @@ describe("Abilities - Gorilla Tactics", () => {
     const darmanitan = game.field.getPlayerPokemon();
 
     game.move.select(MoveId.TACKLE);
-    await game.move.selectEnemyMove(MoveId.PROTECT);
+    await game.move.forceEnemyMove(MoveId.PROTECT);
 
     await game.toEndOfTurn();
     expect(darmanitan.isMoveRestricted(MoveId.SPLASH)).toBe(true);
     expect(darmanitan.isMoveRestricted(MoveId.TACKLE)).toBe(false);
+    const enemy = game.field.getEnemyPokemon();
+    expect(enemy.hp).toBe(enemy.getMaxHp());
   });
 
   it("should activate when a move is succesfully executed but misses", async () => {
@@ -119,7 +121,6 @@ describe("Abilities - Gorilla Tactics", () => {
     const darmanitan = game.field.getPlayerPokemon();
 
     game.move.select(MoveId.TACKLE);
-    await game.move.selectEnemyMove(MoveId.SPLASH);
     await game.setTurnOrder([BattlerIndex.PLAYER, BattlerIndex.ENEMY]);
     await game.move.forceMiss();
     await game.toEndOfTurn();

test/abilities/wimp_out.test.ts

@@ -108,7 +108,7 @@ describe("Abilities - Wimp Out", () => {
   });
 
   it("Trapping moves do not prevent Wimp Out from activating.", async () => {
-    game.override.enemyMoveset([MoveId.SPIRIT_SHACKLE]).startingLevel(53).enemyLevel(45);
+    game.override.enemyMoveset([MoveId.SPIRIT_SHACKLE]).startingLevel(1).passiveAbility(AbilityId.STURDY);
     await game.classicMode.startBattle([SpeciesId.WIMPOD, SpeciesId.TYRUNT]);
 
     game.move.select(MoveId.SPLASH);
@@ -123,7 +123,7 @@ describe("Abilities - Wimp Out", () => {
   });
 
   it("If this Ability activates due to being hit by U-turn or Volt Switch, the user of that move will not be switched out.", async () => {
-    game.override.startingLevel(95).enemyMoveset([MoveId.U_TURN]);
+    game.override.startingLevel(1).enemyMoveset([MoveId.U_TURN]).passiveAbility(AbilityId.STURDY);
     await game.classicMode.startBattle([SpeciesId.WIMPOD, SpeciesId.TYRUNT]);
 
     game.move.select(MoveId.SPLASH);

test/battlerTags/stockpiling.test.ts

@@ -1,6 +1,6 @@
 import { StockpilingTag } from "#app/data/battler-tags";
 import type Pokemon from "#app/field/pokemon";
-import { PokemonSummonData } from "#app/field/pokemon";
+import { PokemonSummonData } from "#app/data/pokemon/pokemon-data";
 import * as messages from "#app/messages";
 import { StatStageChangePhase } from "#app/phases/stat-stage-change-phase";
 import { Stat } from "#enums/stat";

test/battlerTags/substitute.test.ts

@@ -1,5 +1,6 @@
 import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
-import type { PokemonTurnData, TurnMove } from "#app/field/pokemon";
+import type { TurnMove } from "#app/@types/turn-move";
+import type { PokemonTurnData } from "#app/data/pokemon/pokemon-data";
 import type Pokemon from "#app/field/pokemon";
 import { MoveResult } from "#enums/move-result";
 import type BattleScene from "#app/battle-scene";

test/field/pokemon.test.ts

@@ -5,7 +5,7 @@ import { PokeballType } from "#enums/pokeball";
 import type BattleScene from "#app/battle-scene";
 import { MoveId } from "#enums/move-id";
 import { PokemonType } from "#enums/pokemon-type";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 
 describe("Spec - Pokemon", () => {
   let phaserGame: Phaser.Game;

test/moves/heal_block.test.ts

@@ -42,7 +42,7 @@ describe("Moves - Heal Block", () => {
     const player = game.scene.getPlayerPokemon()!;
     const enemy = game.scene.getEnemyPokemon()!;
 
-    player.damageAndUpdate(enemy.getMaxHp() - 1);
+    player.damageAndUpdate(player.getMaxHp() - 1);
 
     game.move.select(MoveId.ABSORB);
     await game.setTurnOrder([BattlerIndex.ENEMY, BattlerIndex.PLAYER]);

test/moves/instruct.test.ts

@@ -1,12 +1,13 @@
-import { BattlerIndex } from "#enums/battler-index";
+import type { TurnMove } from "#app/@types/turn-move";
-import { RandomMoveAttr } from "#app/data/moves/move";
 import { allMoves } from "#app/data/data-lists";
+import { RandomMoveAttr } from "#app/data/moves/move";
 import type Pokemon from "#app/field/pokemon";
-import { MoveResult } from "#enums/move-result";
 import type { MovePhase } from "#app/phases/move-phase";
 import { AbilityId } from "#enums/ability-id";
-import { MoveUseMode } from "#enums/move-use-mode";
+import { BattlerIndex } from "#enums/battler-index";
 import { MoveId } from "#enums/move-id";
+import { MoveResult } from "#enums/move-result";
+import { MoveUseMode } from "#enums/move-use-mode";
 import { SpeciesId } from "#enums/species-id";
 import { Stat } from "#enums/stat";
 import GameManager from "#test/testUtils/gameManager";
@@ -202,21 +203,32 @@ describe("Moves - Instruct", () => {
     game.override.battleStyle("double").enemyMoveset(MoveId.SPLASH).enemySpecies(SpeciesId.MAGIKARP).enemyLevel(1);
     await game.classicMode.startBattle([SpeciesId.HISUI_ELECTRODE, SpeciesId.KOMMO_O]);
 
-    const [electrode, kommo_o] = game.scene.getPlayerField()!;
+    const [electrode, kommo_o] = game.scene.getPlayerField();
-    game.move.changeMoveset(electrode, MoveId.CHLOROBLAST);
+    game.move.changeMoveset(electrode, MoveId.THUNDERBOLT);
     game.move.changeMoveset(kommo_o, MoveId.INSTRUCT);
 
-    game.move.select(MoveId.CHLOROBLAST, BattlerIndex.PLAYER, BattlerIndex.ENEMY);
+    game.move.select(MoveId.THUNDERBOLT, BattlerIndex.PLAYER, BattlerIndex.ENEMY);
     game.move.select(MoveId.INSTRUCT, BattlerIndex.PLAYER_2, BattlerIndex.PLAYER);
     await game.setTurnOrder([BattlerIndex.PLAYER, BattlerIndex.PLAYER_2, BattlerIndex.ENEMY, BattlerIndex.ENEMY_2]);
-    await game.phaseInterceptor.to("BerryPhase");
+    await game.toEndOfTurn();
 
-    // Chloroblast always deals 50% max HP% recoil UNLESS you whiff
+    expect(electrode.getMoveHistory()).toEqual(
-    // due to lack of targets or similar,
+      expect.arrayContaining([
-    // so all we have to do is check whether electrode fainted or not.
+        expect.objectContaining<TurnMove>({
-    // Naturally, both karps should also be dead as well.
+          result: MoveResult.SUCCESS,
-    expect(electrode.isFainted()).toBe(true);
+          move: MoveId.THUNDERBOLT,
-    const [karp1, karp2] = game.scene.getEnemyField()!;
+          targets: [BattlerIndex.ENEMY],
+          useMode: MoveUseMode.NORMAL,
+        }),
+        expect.objectContaining<TurnMove>({
+          result: MoveResult.SUCCESS,
+          move: MoveId.THUNDERBOLT,
+          targets: [BattlerIndex.ENEMY_2],
+          useMode: MoveUseMode.NORMAL,
+        }),
+      ]),
+    );
+    const [karp1, karp2] = game.scene.getEnemyField();
     expect(karp1.isFainted()).toBe(true);
     expect(karp2.isFainted()).toBe(true);
   });

test/moves/steamroller.test.ts

@@ -1,7 +1,7 @@
 import { BattlerIndex } from "#enums/battler-index";
 import { allMoves } from "#app/data/data-lists";
 import { BattlerTagType } from "#app/enums/battler-tag-type";
-import type { DamageCalculationResult } from "#app/field/pokemon";
+import type { DamageCalculationResult } from "#app/@types/damage-result";
 import { AbilityId } from "#enums/ability-id";
 import { MoveId } from "#enums/move-id";
 import { SpeciesId } from "#enums/species-id";

test/mystery-encounter/encounters/the-strong-stuff-encounter.test.ts

@@ -24,7 +24,7 @@ import { BerryModifier, PokemonBaseStatTotalModifier } from "#app/modifier/modif
 import { MysteryEncounterOptionMode } from "#enums/mystery-encounter-option-mode";
 import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { initSceneWithoutEncounterPhase } from "#test/testUtils/gameManagerUtils";
-import { CustomPokemonData } from "#app/data/custom-pokemon-data";
+import { CustomPokemonData } from "#app/data/pokemon/pokemon-data";
 import { CommandPhase } from "#app/phases/command-phase";
 import { MovePhase } from "#app/phases/move-phase";
 import { SelectModifierPhase } from "#app/phases/select-modifier-phase";

test/testUtils/helpers/classicModeHelper.ts

@@ -1,15 +1,16 @@
 import { BattleStyle } from "#app/enums/battle-style";
-import type { SpeciesId } from "#enums/species-id";
 import { getGameMode } from "#app/game-mode";
-import { GameModes } from "#enums/game-modes";
 import overrides from "#app/overrides";
 import { CommandPhase } from "#app/phases/command-phase";
 import { EncounterPhase } from "#app/phases/encounter-phase";
 import { SelectStarterPhase } from "#app/phases/select-starter-phase";
 import { TurnInitPhase } from "#app/phases/turn-init-phase";
+import { GameModes } from "#enums/game-modes";
+import { Nature } from "#enums/nature";
+import type { SpeciesId } from "#enums/species-id";
 import { UiMode } from "#enums/ui-mode";
-import { generateStarter } from "../gameManagerUtils";
+import { generateStarter } from "#test/testUtils/gameManagerUtils";
-import { GameManagerHelper } from "./gameManagerHelper";
+import { GameManagerHelper } from "#test/testUtils/helpers/gameManagerHelper";
 
 /**
  * Helper to handle classic-mode specific operations.
@@ -36,6 +37,12 @@ export class ClassicModeHelper extends GameManagerHelper {
     if (this.game.override.disableShinies) {
       this.game.override.shiny(false).enemyShiny(false);
     }
+    if (this.game.override.normalizeIVs) {
+      this.game.override.playerIVs(31).enemyIVs(31);
+    }
+    if (this.game.override.normalizeNatures) {
+      this.game.override.nature(Nature.HARDY).enemyNature(Nature.HARDY);
+    }
 
     this.game.onNextPrompt("TitlePhase", UiMode.TITLE, () => {
       this.game.scene.gameMode = getGameMode(GameModes.CLASSIC);

test/testUtils/helpers/overridesHelper.ts

@@ -1,35 +1,55 @@
-import type { Variant } from "#app/sprites/variant";
+/** biome-ignore-start lint/correctness/noUnusedImports: tsdoc imports */
+import type { NewArenaEvent } from "#app/events/battle-scene";
+/** biome-ignore-end lint/correctness/noUnusedImports: tsdoc imports */
+
 import { Weather } from "#app/data/weather";
-import { AbilityId } from "#enums/ability-id";
 import type { ModifierOverride } from "#app/modifier/modifier-type";
-import type { BattleStyle } from "#app/overrides";
+import type { BattleStyle, RandomTrainerOverride } from "#app/overrides";
 import Overrides, { defaultOverrides } from "#app/overrides";
-import type { Unlockables } from "#enums/unlockables";
+import type { Variant } from "#app/sprites/variant";
+import { coerceArray, shiftCharCodes } from "#app/utils/common";
+import { AbilityId } from "#enums/ability-id";
+import type { BattleType } from "#enums/battle-type";
 import { BiomeId } from "#enums/biome-id";
 import { MoveId } from "#enums/move-id";
 import type { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import type { MysteryEncounterType } from "#enums/mystery-encounter-type";
+import { Nature } from "#enums/nature";
 import { SpeciesId } from "#enums/species-id";
 import { StatusEffect } from "#enums/status-effect";
+import type { Unlockables } from "#enums/unlockables";
 import type { WeatherType } from "#enums/weather-type";
+import { GameManagerHelper } from "#test/testUtils/helpers/gameManagerHelper";
 import { expect, vi } from "vitest";
-import { GameManagerHelper } from "./gameManagerHelper";
-import { coerceArray, shiftCharCodes } from "#app/utils/common";
-import type { RandomTrainerOverride } from "#app/overrides";
-import type { BattleType } from "#enums/battle-type";
 
 /**
  * Helper to handle overrides in tests
  */
 export class OverridesHelper extends GameManagerHelper {
-  /** If `true`, removes the starting items from enemies at the start of each test; default `true` */
+  /**
+   * If `true`, removes the starting items from enemies at the start of each test.
+   * @defaultValue `true`
+   */
   public removeEnemyStartingItems = true;
-  /** If `true`, sets the shiny overrides to disable shinies at the start of each test; default `true` */
+  /**
+   * If `true`, sets the shiny overrides to disable shinies at the start of each test.
+   * @defaultValue `true`
+   */
   public disableShinies = true;
+  /**
+   * If `true`, will set the IV overrides for player and enemy pokemon to `31` at the start of each test.
+   * @defaultValue `true`
+   */
+  public normalizeIVs = true;
+  /**
+   * If `true`, will set the Nature overrides for player and enemy pokemon to a neutral nature at the start of each test.
+   * @defaultValue `true`
+   */
+  public normalizeNatures = true;
 
   /**
    * Override the starting biome
-   * @warning Any event listeners that are attached to [NewArenaEvent](events\battle-scene.ts) may need to be handled down the line
+   * @warning Any event listeners that are attached to {@linkcode NewArenaEvent} may need to be handled down the line
    * @param biome - The biome to set
    */
   public startingBiome(biome: BiomeId): this {
@@ -219,6 +239,80 @@ export class OverridesHelper extends GameManagerHelper {
     return this;
   }
 
+  /**
+   * Overrides the IVs of the player pokemon
+   * @param ivs - If set to a number, all IVs are set to the same value. Must be between `0` and `31`!
+   *
+   * If set to an array, that array is applied to the pokemon's IV field as-is.
+   * All values must be between `0` and `31`, and the array must be of exactly length `6`!
+   *
+   * If set to `null`, the override is disabled.
+   * @returns `this`
+   */
+  public playerIVs(ivs: number | number[] | null): this {
+    this.normalizeIVs = false;
+    vi.spyOn(Overrides, "IVS_OVERRIDE", "get").mockReturnValue(ivs);
+    if (ivs === null) {
+      this.log("Player IVs override disabled!");
+    } else {
+      this.log(`Player IVs set to ${ivs}!`);
+    }
+    return this;
+  }
+
+  /**
+   * Overrides the nature of the player's pokemon
+   * @param nature - The nature to set, or `null` to disable the override.
+   * @returns `this`
+   */
+  public nature(nature: Nature | null): this {
+    this.normalizeNatures = false;
+    vi.spyOn(Overrides, "NATURE_OVERRIDE", "get").mockReturnValue(nature);
+    if (nature === null) {
+      this.log("Player Nature override disabled!");
+    } else {
+      this.log(`Player Nature set to ${Nature[nature]} (=${nature})!`);
+    }
+    return this;
+  }
+
+  /**
+   * Overrides the IVs of the enemy pokemon
+   * @param ivs - If set to a number, all IVs are set to the same value. Must be between `0` and `31`!
+   *
+   * If set to an array, that array is applied to the pokemon's IV field as-is.
+   * All values must be between `0` and `31`, and the array must be of exactly length `6`!
+   *
+   * If set to `null`, the override is disabled.
+   * @returns `this`
+   */
+  public enemyIVs(ivs: number | number[] | null): this {
+    this.normalizeIVs = false;
+    vi.spyOn(Overrides, "ENEMY_IVS_OVERRIDE", "get").mockReturnValue(ivs);
+    if (ivs === null) {
+      this.log("Enemy IVs override disabled!");
+    } else {
+      this.log(`Enemy IVs set to ${ivs}!`);
+    }
+    return this;
+  }
+
+  /**
+   * Overrides the nature of the enemy's pokemon
+   * @param nature - The nature to set, or `null` to disable the override.
+   * @returns `this`
+   */
+  public enemyNature(nature: Nature | null): this {
+    this.normalizeNatures = false;
+    vi.spyOn(Overrides, "ENEMY_NATURE_OVERRIDE", "get").mockReturnValue(nature);
+    if (nature === null) {
+      this.log("Enemy Nature override disabled!");
+    } else {
+      this.log(`Enemy Nature set to ${Nature[nature]} (=${nature})!`);
+    }
+    return this;
+  }
+
   /**
    * Override each wave to not have standard trainer battles
    * @returns `this`