[Misc] Rework some aspects of timed events (#5099)

* Refactor timed event changes

* Use getWeather function

* Add mystery encounter tier change/disabling to timed events

* Event luck boost, event encounter helper function

* Events without shiny boost shouldn't give shiny charm

* globalScene -> this in battle scene class

* Change event pools

src/battle-scene.ts

@@ -3390,7 +3390,8 @@ export default class BattleScene extends SceneBase {
     const previousEncounter = this.mysteryEncounterSaveData.encounteredEvents.length > 0 ?
       this.mysteryEncounterSaveData.encounteredEvents[this.mysteryEncounterSaveData.encounteredEvents.length - 1].type
       : null;
-    const biomeMysteryEncounters = mysteryEncountersByBiome.get(this.arena.biomeType) ?? [];
+    const disabledEncounters = this.eventManager.getEventMysteryEncountersDisabled();
+    const biomeMysteryEncounters = mysteryEncountersByBiome.get(this.arena.biomeType)?.filter(enc => !disabledEncounters.includes(enc)) ?? [];
     // If no valid encounters exist at tier, checks next tier down, continuing until there are some encounters available
     while (availableEncounters.length === 0 && tier !== null) {
       availableEncounters = biomeMysteryEncounters
@@ -3399,7 +3400,7 @@ export default class BattleScene extends SceneBase {
           if (!encounterCandidate) {
             return false;
           }
-          if (encounterCandidate.encounterTier !== tier) {
+          if (this.eventManager.getMysteryEncounterTierForEvent(encounterType, encounterCandidate.encounterTier) !== tier) {
             return false;
           }
           const disallowedGameModes = encounterCandidate.disallowedGameModes;

src/data/mystery-encounters/encounters/berries-abound-encounter.ts

@@ -4,6 +4,7 @@ import type {
 import {
   generateModifierType,
   generateModifierTypeOption,
+  getRandomEncounterSpecies,
   initBattleWithEnemyConfig,
   leaveEncounterWithoutBattle,
   setEncounterExp,
@@ -11,17 +12,15 @@ import {
 } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
 import type { PlayerPokemon } from "#app/field/pokemon";
 import type Pokemon from "#app/field/pokemon";
-import { EnemyPokemon } from "#app/field/pokemon";
 import type {
   BerryModifierType,
   ModifierTypeOption } from "#app/modifier/modifier-type";
 import {
-  getPartyLuckValue,
   ModifierPoolType,
   modifierTypes,
   regenerateModifierPoolThresholds,
 } from "#app/modifier/modifier-type";
-import { randSeedInt, randSeedItem } from "#app/utils";
+import { randSeedInt } from "#app/utils";
 import { BattlerTagType } from "#enums/battler-tag-type";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
 import { globalScene } from "#app/global-scene";
@@ -31,7 +30,6 @@ import { queueEncounterMessage, showEncounterText } from "#app/data/mystery-enco
 import { getPokemonNameWithAffix } from "#app/messages";
 import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { MysteryEncounterOptionMode } from "#enums/mystery-encounter-option-mode";
-import { TrainerSlot } from "#app/data/trainer-config";
 import { applyModifierTypeToPlayerPokemon, getEncounterPokemonLevelForWave, getHighestStatPlayerPokemon, getSpriteKeysFromPokemon, STANDARD_ENCOUNTER_BOOSTED_LEVEL_MODIFIER } from "#app/data/mystery-encounters/utils/encounter-pokemon-utils";
 import PokemonData from "#app/system/pokemon-data";
 import { BerryModifier } from "#app/modifier/modifier";
@@ -40,8 +38,6 @@ import { BerryType } from "#enums/berry-type";
 import { PERMANENT_STATS, Stat } from "#enums/stat";
 import { StatStageChangePhase } from "#app/phases/stat-stage-change-phase";
 import { CLASSIC_MODE_MYSTERY_ENCOUNTER_WAVES } from "#app/game-mode";
-import type PokemonSpecies from "#app/data/pokemon-species";
-import { getPokemonSpecies } from "#app/data/pokemon-species";
 
 /** the i18n namespace for the encounter */
 const namespace = "mysteryEncounters/berriesAbound";
@@ -69,20 +65,12 @@ export const BerriesAboundEncounter: MysteryEncounter =
 
       // Calculate boss mon
       const level = getEncounterPokemonLevelForWave(STANDARD_ENCOUNTER_BOOSTED_LEVEL_MODIFIER);
-      let bossSpecies: PokemonSpecies;
+      const bossPokemon = getRandomEncounterSpecies(level, true);
-      if (globalScene.eventManager.isEventActive() && globalScene.eventManager.activeEvent()?.uncommonBreedEncounters && randSeedInt(2) === 1) {
-        const eventEncounter = randSeedItem(globalScene.eventManager.activeEvent()!.uncommonBreedEncounters!);
-        const levelSpecies = getPokemonSpecies(eventEncounter.species).getWildSpeciesForLevel(level, eventEncounter.allowEvolution ?? false, true, globalScene.gameMode);
-        bossSpecies = getPokemonSpecies( levelSpecies );
-      } else {
-        bossSpecies = globalScene.arena.randomSpecies(globalScene.currentBattle.waveIndex, level, 0, getPartyLuckValue(globalScene.getPlayerParty()), true);
-      }
-      const bossPokemon = new EnemyPokemon(bossSpecies, level, TrainerSlot.NONE, true);
       encounter.setDialogueToken("enemyPokemon", getPokemonNameWithAffix(bossPokemon));
       const config: EnemyPartyConfig = {
         pokemonConfigs: [{
           level: level,
-          species: bossSpecies,
+          species: bossPokemon.species,
           dataSource: new PokemonData(bossPokemon),
           isBoss: true
         }],

src/data/mystery-encounters/encounters/delibirdy-encounter.ts

@@ -41,7 +41,7 @@ const OPTION_3_DISALLOWED_MODIFIERS = [
 const DELIBIRDY_MONEY_PRICE_MULTIPLIER = 2;
 
 const doEventReward = () => {
-  const event_buff = globalScene.eventManager.activeEvent()?.delibirdyBuff ?? [];
+  const event_buff = globalScene.eventManager.getDelibirdyBuff();
   if (event_buff.length > 0) {
     const candidates = event_buff.filter((c => {
       const mtype = generateModifierType(modifierTypes[c]);

src/data/mystery-encounters/encounters/fight-or-flight-encounter.ts

@@ -2,6 +2,7 @@ import { MysteryEncounterOptionBuilder } from "#app/data/mystery-encounters/myst
 import type {
   EnemyPartyConfig } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
 import {
+  getRandomEncounterSpecies,
   initBattleWithEnemyConfig,
   leaveEncounterWithoutBattle,
   setEncounterExp,
@@ -9,12 +10,10 @@ import {
 } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
 import { STEALING_MOVES } from "#app/data/mystery-encounters/requirements/requirement-groups";
 import type Pokemon from "#app/field/pokemon";
-import { EnemyPokemon } from "#app/field/pokemon";
 import { ModifierTier } from "#app/modifier/modifier-tier";
 import type {
   ModifierTypeOption } from "#app/modifier/modifier-type";
 import {
-  getPartyLuckValue,
   getPlayerModifierTypeOptions,
   ModifierPoolType,
   regenerateModifierPoolThresholds,
@@ -26,16 +25,13 @@ import { MysteryEncounterBuilder } from "#app/data/mystery-encounters/mystery-en
 import { MoveRequirement } from "#app/data/mystery-encounters/mystery-encounter-requirements";
 import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { MysteryEncounterOptionMode } from "#enums/mystery-encounter-option-mode";
-import { TrainerSlot } from "#app/data/trainer-config";
 import { getEncounterPokemonLevelForWave, getSpriteKeysFromPokemon, STANDARD_ENCOUNTER_BOOSTED_LEVEL_MODIFIER } from "#app/data/mystery-encounters/utils/encounter-pokemon-utils";
 import PokemonData from "#app/system/pokemon-data";
 import { BattlerTagType } from "#enums/battler-tag-type";
 import { queueEncounterMessage } from "#app/data/mystery-encounters/utils/encounter-dialogue-utils";
-import { randSeedInt, randSeedItem } from "#app/utils";
+import { randSeedInt } from "#app/utils";
 import { StatStageChangePhase } from "#app/phases/stat-stage-change-phase";
 import { CLASSIC_MODE_MYSTERY_ENCOUNTER_WAVES } from "#app/game-mode";
-import type PokemonSpecies from "#app/data/pokemon-species";
-import { getPokemonSpecies } from "#app/data/pokemon-species";
 
 /** the i18n namespace for the encounter */
 const namespace = "mysteryEncounters/fightOrFlight";
@@ -63,20 +59,12 @@ export const FightOrFlightEncounter: MysteryEncounter =
 
       // Calculate boss mon
       const level = getEncounterPokemonLevelForWave(STANDARD_ENCOUNTER_BOOSTED_LEVEL_MODIFIER);
-      let bossSpecies: PokemonSpecies;
+      const bossPokemon = getRandomEncounterSpecies(level, true);
-      if (globalScene.eventManager.isEventActive() && globalScene.eventManager.activeEvent()?.uncommonBreedEncounters && randSeedInt(2) === 1) {
-        const eventEncounter = randSeedItem(globalScene.eventManager.activeEvent()!.uncommonBreedEncounters!);
-        const levelSpecies = getPokemonSpecies(eventEncounter.species).getWildSpeciesForLevel(level, eventEncounter.allowEvolution ?? false, true, globalScene.gameMode);
-        bossSpecies = getPokemonSpecies( levelSpecies );
-      } else {
-        bossSpecies = globalScene.arena.randomSpecies(globalScene.currentBattle.waveIndex, level, 0, getPartyLuckValue(globalScene.getPlayerParty()), true);
-      }
-      const bossPokemon = new EnemyPokemon(bossSpecies, level, TrainerSlot.NONE, true);
       encounter.setDialogueToken("enemyPokemon", bossPokemon.getNameToRender());
       const config: EnemyPartyConfig = {
         pokemonConfigs: [{
           level: level,
-          species: bossSpecies,
+          species: bossPokemon.species,
           dataSource: new PokemonData(bossPokemon),
           isBoss: true,
           tags: [ BattlerTagType.MYSTERY_ENCOUNTER_POST_SUMMON ],

src/data/mystery-encounters/encounters/uncommon-breed-encounter.ts

@@ -1,10 +1,10 @@
 import { MysteryEncounterOptionBuilder } from "#app/data/mystery-encounters/mystery-encounter-option";
 import type { EnemyPartyConfig } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
-import { initBattleWithEnemyConfig, leaveEncounterWithoutBattle, setEncounterExp, setEncounterRewards } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
+import { getRandomEncounterSpecies, initBattleWithEnemyConfig, leaveEncounterWithoutBattle, setEncounterExp, setEncounterRewards } from "#app/data/mystery-encounters/utils/encounter-phase-utils";
 import { CHARMING_MOVES } from "#app/data/mystery-encounters/requirements/requirement-groups";
 import type Pokemon from "#app/field/pokemon";
-import { EnemyPokemon, PokemonMove } from "#app/field/pokemon";
+import type { EnemyPokemon } from "#app/field/pokemon";
-import { getPartyLuckValue } from "#app/modifier/modifier-type";
+import { PokemonMove } from "#app/field/pokemon";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
 import { globalScene } from "#app/global-scene";
 import type MysteryEncounter from "#app/data/mystery-encounters/mystery-encounter";
@@ -12,10 +12,9 @@ import { MysteryEncounterBuilder } from "#app/data/mystery-encounters/mystery-en
 import { MoveRequirement, PersistentModifierRequirement } from "#app/data/mystery-encounters/mystery-encounter-requirements";
 import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { MysteryEncounterOptionMode } from "#enums/mystery-encounter-option-mode";
-import { TrainerSlot } from "#app/data/trainer-config";
 import { catchPokemon, getHighestLevelPlayerPokemon, getSpriteKeysFromPokemon } from "#app/data/mystery-encounters/utils/encounter-pokemon-utils";
 import PokemonData from "#app/system/pokemon-data";
-import { isNullOrUndefined, randSeedInt, randSeedItem } from "#app/utils";
+import { isNullOrUndefined, randSeedInt } from "#app/utils";
 import type { Moves } from "#enums/moves";
 import { BattlerIndex } from "#app/battle";
 import { SelfStatusMove } from "#app/data/move";
@@ -26,8 +25,6 @@ import { BerryModifier } from "#app/modifier/modifier";
 import { StatStageChangePhase } from "#app/phases/stat-stage-change-phase";
 import { Stat } from "#enums/stat";
 import { CLASSIC_MODE_MYSTERY_ENCOUNTER_WAVES } from "#app/game-mode";
-import type PokemonSpecies from "#app/data/pokemon-species";
-import { getPokemonSpecies } from "#app/data/pokemon-species";
 
 /** the i18n namespace for the encounter */
 const namespace = "mysteryEncounters/uncommonBreed";
@@ -56,15 +53,7 @@ export const UncommonBreedEncounter: MysteryEncounter =
       // Calculate boss mon
       // Level equal to 2 below highest party member
       const level = getHighestLevelPlayerPokemon(false, true).level - 2;
-      let species: PokemonSpecies;
+      const pokemon = getRandomEncounterSpecies(level, true, true);
-      if (globalScene.eventManager.isEventActive() && globalScene.eventManager.activeEvent()?.uncommonBreedEncounters && randSeedInt(2) === 1) {
-        const eventEncounter = randSeedItem(globalScene.eventManager.activeEvent()!.uncommonBreedEncounters!);
-        const levelSpecies = getPokemonSpecies(eventEncounter.species).getWildSpeciesForLevel(level, eventEncounter.allowEvolution ?? false, true, globalScene.gameMode);
-        species = getPokemonSpecies( levelSpecies );
-      } else {
-        species = globalScene.arena.randomSpecies(globalScene.currentBattle.waveIndex, level, 0, getPartyLuckValue(globalScene.getPlayerParty()), true);
-      }
-      const pokemon = new EnemyPokemon(species, level, TrainerSlot.NONE, true);
 
       // Pokemon will always have one of its egg moves in its moveset
       const eggMoves = pokemon.getEggMoves();
@@ -92,7 +81,7 @@ export const UncommonBreedEncounter: MysteryEncounter =
       const config: EnemyPartyConfig = {
         pokemonConfigs: [{
           level: level,
-          species: species,
+          species: pokemon.species,
           dataSource: new PokemonData(pokemon),
           isBoss: false,
           tags: [ BattlerTagType.MYSTERY_ENCOUNTER_POST_SUMMON ],

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

@@ -6,9 +6,9 @@ import { AVERAGE_ENCOUNTERS_PER_RUN_TARGET, WEIGHT_INCREMENT_ON_SPAWN_MISS } fro
 import { showEncounterText } from "#app/data/mystery-encounters/utils/encounter-dialogue-utils";
 import type { AiType, PlayerPokemon } from "#app/field/pokemon";
 import type Pokemon from "#app/field/pokemon";
-import { FieldPosition, PokemonMove, PokemonSummonData } from "#app/field/pokemon";
+import { EnemyPokemon, FieldPosition, PokemonMove, PokemonSummonData } from "#app/field/pokemon";
 import type { CustomModifierSettings, ModifierType } from "#app/modifier/modifier-type";
-import { ModifierPoolType, ModifierTypeGenerator, ModifierTypeOption, modifierTypes, regenerateModifierPoolThresholds } from "#app/modifier/modifier-type";
+import { getPartyLuckValue, ModifierPoolType, ModifierTypeGenerator, ModifierTypeOption, modifierTypes, regenerateModifierPoolThresholds } from "#app/modifier/modifier-type";
 import { MysteryEncounterBattlePhase, MysteryEncounterBattleStartCleanupPhase, MysteryEncounterPhase, MysteryEncounterRewardsPhase } from "#app/phases/mystery-encounter-phases";
 import type PokemonData from "#app/system/pokemon-data";
 import type { OptionSelectConfig, OptionSelectItem } from "#app/ui/abstact-option-select-ui-handler";
@@ -16,7 +16,7 @@ import type { PartyOption, PokemonSelectFilter } from "#app/ui/party-ui-handler"
 import { PartyUiMode } from "#app/ui/party-ui-handler";
 import { Mode } from "#app/ui/ui";
 import * as Utils from "#app/utils";
-import { isNullOrUndefined } from "#app/utils";
+import { isNullOrUndefined, randSeedInt, randSeedItem } from "#app/utils";
 import type { BattlerTagType } from "#enums/battler-tag-type";
 import { Biome } from "#enums/biome";
 import type { TrainerType } from "#enums/trainer-type";
@@ -45,6 +45,7 @@ import { PartyExpPhase } from "#app/phases/party-exp-phase";
 import type { Variant } from "#app/data/variant";
 import { StatusEffect } from "#enums/status-effect";
 import { globalScene } from "#app/global-scene";
+import { getPokemonSpecies } from "#app/data/pokemon-species";
 
 /**
  * Animates exclamation sprite over trainer's head at start of encounter
@@ -874,6 +875,41 @@ export function handleMysteryEncounterTurnStartEffects(): boolean {
   return false;
 }
 
+/**
+ * Helper function for encounters such as {@linkcode UncommonBreedEncounter} which call for a random species including event encounters.
+ * If the mon is from the event encounter list, it will do an extra shiny roll.
+ * @param level the level of the mon, which differs between MEs
+ * @param isBoss whether the mon should be a Boss
+ * @param rerollHidden whether the mon should get an extra roll for Hidden Ability
+ * @returns {@linkcode EnemyPokemon} for the requested encounter
+ */
+export function getRandomEncounterSpecies(level: number, isBoss: boolean = false, rerollHidden: boolean = false): EnemyPokemon {
+  let bossSpecies: PokemonSpecies;
+  let isEventEncounter = false;
+  const eventEncounters = globalScene.eventManager.getEventEncounters();
+
+  if (eventEncounters.length > 0 && randSeedInt(2) === 1) {
+    const eventEncounter = randSeedItem(eventEncounters);
+    const levelSpecies = getPokemonSpecies(eventEncounter.species).getWildSpeciesForLevel(level, !isNullOrUndefined(eventEncounter.blockEvolution), isBoss, globalScene.gameMode);
+    isEventEncounter = true;
+    bossSpecies = getPokemonSpecies(levelSpecies);
+  } else {
+    bossSpecies = globalScene.arena.randomSpecies(globalScene.currentBattle.waveIndex, level, 0, getPartyLuckValue(globalScene.getPlayerParty()), isBoss);
+  }
+  const ret = new EnemyPokemon(bossSpecies, level, TrainerSlot.NONE, isBoss);
+
+  //Reroll shiny for event encounters
+  if (isEventEncounter && !ret.shiny) {
+    ret.trySetShinySeed();
+  }
+  //Reroll hidden ability
+  if (rerollHidden && ret.abilityIndex !== 2 && ret.species.abilityHidden) {
+    ret.tryRerollHiddenAbilitySeed();
+  }
+
+  return ret;
+}
+
 /**
  * TODO: remove once encounter spawn rate is finalized
  * Just a helper function to calculate aggregate stats for MEs in a Classic run

src/data/weather.ts

@@ -375,8 +375,8 @@ export function getRandomWeatherType(arena: Arena): WeatherType {
       break;
   }
 
-  if (arena.biomeType === Biome.TOWN && globalScene.eventManager.isEventActive() && (globalScene.eventManager.activeEvent()?.weather?.length ?? 0) > 0) {
+  if (arena.biomeType === Biome.TOWN && globalScene.eventManager.isEventActive()) {
-    globalScene.eventManager.activeEvent()?.weather?.map(w => weatherPool.push(w));
+    globalScene.eventManager.getWeather()?.map(w => weatherPool.push(w));
   }
 
   if (weatherPool.length > 1) {

src/field/pokemon.ts

@@ -10,7 +10,7 @@ import type Move from "#app/data/move";
 import { HighCritAttr, HitsTagAttr, applyMoveAttrs, FixedDamageAttr, VariableAtkAttr, allMoves, MoveCategory, TypelessAttr, CritOnlyAttr, getMoveTargets, OneHitKOAttr, VariableMoveTypeAttr, VariableDefAttr, AttackMove, ModifiedDamageAttr, VariableMoveTypeMultiplierAttr, IgnoreOpponentStatStagesAttr, SacrificialAttr, VariableMoveCategoryAttr, CounterDamageAttr, StatStageChangeAttr, RechargeAttr, IgnoreWeatherTypeDebuffAttr, BypassBurnDamageReductionAttr, SacrificialAttrOnHit, OneHitKOAccuracyAttr, RespectAttackTypeImmunityAttr, MoveTarget, CombinedPledgeStabBoostAttr, VariableMoveTypeChartAttr } from "#app/data/move";
 import type { PokemonSpeciesForm } from "#app/data/pokemon-species";
 import { default as PokemonSpecies, getFusedSpeciesName, getPokemonSpecies, getPokemonSpeciesForm } from "#app/data/pokemon-species";
-import { CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER, getStarterValueFriendshipCap, speciesStarterCosts } from "#app/data/balance/starters";
+import { getStarterValueFriendshipCap, speciesStarterCosts } from "#app/data/balance/starters";
 import { starterPassiveAbilities } from "#app/data/balance/passives";
 import type { Constructor } from "#app/utils";
 import { isNullOrUndefined, randSeedInt, type nil } from "#app/utils";
@@ -1955,7 +1955,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
    * @param thresholdOverride number that is divided by 2^16 (65536) to get the shiny chance, overrides {@linkcode shinyThreshold} if set (bypassing shiny rate modifiers such as Shiny Charm)
    * @returns true if the Pokemon has been set as a shiny, false otherwise
    */
-  trySetShiny(thresholdOverride?: integer): boolean {
+  trySetShiny(thresholdOverride?: number): boolean {
     // Shiny Pokemon should not spawn in the end biome in endless
     if (globalScene.gameMode.isEndless && globalScene.arena.biomeType === Biome.END) {
       return false;
@@ -1967,7 +1967,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     const E = globalScene.gameData.trainerId ^ globalScene.gameData.secretId;
     const F = rand1 ^ rand2;
 
-    const shinyThreshold = new Utils.IntegerHolder(BASE_SHINY_CHANCE);
+    const shinyThreshold = new Utils.NumberHolder(BASE_SHINY_CHANCE);
     if (thresholdOverride === undefined) {
       if (globalScene.eventManager.isEventActive()) {
         shinyThreshold.value *= globalScene.eventManager.getShinyMultiplier();
@@ -2058,6 +2058,38 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     }
   }
 
+  /**
+   * Function that tries to set a Pokemon to have its hidden ability based on seed, if it exists.
+   * For manual use only, usually to roll a Pokemon's hidden ability chance a second time.
+   *
+   * The base hidden ability odds are {@linkcode BASE_HIDDEN_ABILITY_CHANCE} / `65536`
+   * @param thresholdOverride number that is divided by `2^16` (`65536`) to get the HA chance, overrides {@linkcode haThreshold} if set (bypassing HA rate modifiers such as Ability Charm)
+   * @param applyModifiersToOverride If {@linkcode thresholdOverride} is set and this is true, will apply Ability Charm to {@linkcode thresholdOverride}
+   * @returns `true` if the Pokemon has been set to have its hidden ability, `false` otherwise
+   */
+  public tryRerollHiddenAbilitySeed(thresholdOverride?: number, applyModifiersToOverride?: boolean): boolean {
+    if (!this.species.abilityHidden) {
+      return false;
+    }
+    const haThreshold = new Utils.NumberHolder(BASE_HIDDEN_ABILITY_CHANCE);
+    if (thresholdOverride === undefined || applyModifiersToOverride) {
+      if (thresholdOverride !== undefined && applyModifiersToOverride) {
+        haThreshold.value = thresholdOverride;
+      }
+      if (!this.hasTrainer()) {
+        globalScene.applyModifiers(HiddenAbilityRateBoosterModifier, true, haThreshold);
+      }
+    } else {
+      haThreshold.value = thresholdOverride;
+    }
+
+    if (randSeedInt(65536) < haThreshold.value) {
+      this.abilityIndex = 2;
+    }
+
+    return this.abilityIndex === 2;
+  }
+
   public generateFusionSpecies(forStarter?: boolean): void {
     const hiddenAbilityChance = new Utils.NumberHolder(BASE_HIDDEN_ABILITY_CHANCE);
     if (!this.hasTrainer()) {
@@ -4328,10 +4360,7 @@ export class PlayerPokemon extends Pokemon {
       ].filter(d => !!d);
       const amount = new Utils.NumberHolder(friendship);
       globalScene.applyModifier(PokemonFriendshipBoosterModifier, true, this, amount);
-      let candyFriendshipMultiplier = CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER;
+      const candyFriendshipMultiplier = globalScene.eventManager.getClassicFriendshipMultiplier();
-      if (globalScene.eventManager.isEventActive()) {
-        candyFriendshipMultiplier *= globalScene.eventManager.getFriendshipMultiplier();
-      }
       const starterAmount = new Utils.NumberHolder(Math.floor(amount.value * (globalScene.gameMode.isClassic ? candyFriendshipMultiplier : 1) / (fusionStarterSpeciesId ? 2 : 1)));
 
       // Add friendship to this PlayerPokemon

src/modifier/modifier-type.ts

@@ -2537,9 +2537,10 @@ export function getPartyLuckValue(party: Pokemon[]): integer {
     }, 0, globalScene.seed);
     return DailyLuck.value;
   }
-  const luck = Phaser.Math.Clamp(party.map(p => p.isAllowedInBattle() ? p.getLuck() : 0)
+  const eventSpecies = globalScene.eventManager.getEventLuckBoostedSpecies();
+  const luck = Phaser.Math.Clamp(party.map(p => p.isAllowedInBattle() ? p.getLuck() + (eventSpecies.includes(p.species.speciesId) ? 1 : 0) : 0)
     .reduce((total: integer, value: integer) => total += value, 0), 0, 14);
-  return luck ?? 0;
+  return Math.min(globalScene.eventManager.getEventLuckBoost() + (luck ?? 0), 14);
 }
 
 export function getLuckString(luckValue: integer): string {

src/phases/trainer-victory-phase.ts

@@ -29,7 +29,7 @@ export class TrainerVictoryPhase extends BattlePhase {
       globalScene.unshiftPhase(new ModifierRewardPhase(modifierRewardFunc));
     }
 
-    if (globalScene.eventManager.isEventActive()) {
+    if (globalScene.eventManager.getShinyMultiplier() > 1) { //If a shiny boosting event is active
       for (const rewardFunc of globalScene.currentBattle.trainer?.config.eventRewardFuncs!) {
         globalScene.unshiftPhase(new ModifierRewardPhase(rewardFunc));
       }
@@ -39,7 +39,11 @@ export class TrainerVictoryPhase extends BattlePhase {
     // Validate Voucher for boss trainers
     if (vouchers.hasOwnProperty(TrainerType[trainerType])) {
       if (!globalScene.validateVoucher(vouchers[TrainerType[trainerType]]) && globalScene.currentBattle.trainer?.config.isBoss) {
-        globalScene.unshiftPhase(new ModifierRewardPhase([ modifierTypes.VOUCHER, modifierTypes.VOUCHER, modifierTypes.VOUCHER_PLUS, modifierTypes.VOUCHER_PREMIUM ][vouchers[TrainerType[trainerType]].voucherType]));
+        if (globalScene.eventManager.getUpgradeUnlockedVouchers()) {
+          globalScene.unshiftPhase(new ModifierRewardPhase([ modifierTypes.VOUCHER_PLUS, modifierTypes.VOUCHER_PLUS, modifierTypes.VOUCHER_PLUS, modifierTypes.VOUCHER_PREMIUM ][vouchers[TrainerType[trainerType]].voucherType]));
+        } else {
+          globalScene.unshiftPhase(new ModifierRewardPhase([ modifierTypes.VOUCHER, modifierTypes.VOUCHER, modifierTypes.VOUCHER_PLUS, modifierTypes.VOUCHER_PREMIUM ][vouchers[TrainerType[trainerType]].voucherType]));
+        }
       }
     }
     // Breeders in Space achievement

src/test/utils/mocks/mockTimedEventManager.ts

@@ -1,3 +1,4 @@
+import { CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER } from "#app/data/balance/starters";
 import { TimedEventManager } from "#app/timed-event-manager";
 
 /** Mock TimedEventManager so that ongoing events don't impact tests */
@@ -8,8 +9,8 @@ export class MockTimedEventManager extends TimedEventManager {
   override isEventActive(): boolean {
     return false;
   }
-  override getFriendshipMultiplier(): number {
+  override getClassicFriendshipMultiplier(): number {
-    return 1;
+    return CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER;
   }
   override getShinyMultiplier(): number {
     return 1;

src/timed-event-manager.ts

@@ -1,14 +1,19 @@
 import { globalScene } from "#app/global-scene";
 import { TextStyle, addTextObject } from "#app/ui/text";
 import type { nil } from "#app/utils";
+import { isNullOrUndefined } from "#app/utils";
 import i18next from "i18next";
 import { Species } from "#enums/species";
 import type { WeatherPoolEntry } from "#app/data/weather";
 import { WeatherType } from "#enums/weather-type";
+import { CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER } from "./data/balance/starters";
+import { MysteryEncounterType } from "./enums/mystery-encounter-type";
+import { MysteryEncounterTier } from "./enums/mystery-encounter-tier";
 
 export enum EventType {
   SHINY,
-  NO_TIMER_DISPLAY
+  NO_TIMER_DISPLAY,
+  LUCK
 }
 
 interface EventBanner {
@@ -21,19 +26,29 @@ interface EventBanner {
 
 interface EventEncounter {
   species: Species;
-  allowEvolution?: boolean;
+  blockEvolution?: boolean;
+}
+
+interface EventMysteryEncounterTier {
+  mysteryEncounter: MysteryEncounterType;
+  tier?: MysteryEncounterTier;
+  disable?: boolean;
 }
 
 interface TimedEvent extends EventBanner {
   name: string;
   eventType: EventType;
   shinyMultiplier?: number;
-  friendshipMultiplier?: number;
+  classicFriendshipMultiplier?: number;
+  luckBoost?: number;
+  upgradeUnlockedVouchers?: boolean;
   startDate: Date;
   endDate: Date;
-  uncommonBreedEncounters?: EventEncounter[];
+  eventEncounters?: EventEncounter[];
   delibirdyBuff?: string[];
   weather?: WeatherPoolEntry[];
+  mysteryEncounterTierChanges?: EventMysteryEncounterTier[];
+  luckBoostedSpecies?: Species[];
 }
 
 const timedEvents: TimedEvent[] = [
@@ -41,36 +56,94 @@ const timedEvents: TimedEvent[] = [
     name: "Winter Holiday Update",
     eventType: EventType.SHINY,
     shinyMultiplier: 2,
-    friendshipMultiplier: 1,
+    upgradeUnlockedVouchers: true,
     startDate: new Date(Date.UTC(2024, 11, 21, 0)),
     endDate: new Date(Date.UTC(2025, 0, 4, 0)),
     bannerKey: "winter_holidays2024-event-",
     scale: 0.21,
     availableLangs: [ "en", "de", "it", "fr", "ja", "ko", "es-ES", "pt-BR", "zh-CN" ],
-    uncommonBreedEncounters: [
+    eventEncounters: [
-      { species: Species.GIMMIGHOUL },
+      { species: Species.GIMMIGHOUL, blockEvolution: true },
       { species: Species.DELIBIRD },
-      { species: Species.STANTLER, allowEvolution: true },
+      { species: Species.STANTLER },
-      { species: Species.CYNDAQUIL, allowEvolution: true },
+      { species: Species.CYNDAQUIL },
-      { species: Species.PIPLUP, allowEvolution: true },
+      { species: Species.PIPLUP },
-      { species: Species.CHESPIN, allowEvolution: true },
+      { species: Species.CHESPIN },
-      { species: Species.BALTOY, allowEvolution: true },
+      { species: Species.BALTOY },
-      { species: Species.SNOVER, allowEvolution: true },
+      { species: Species.SNOVER },
-      { species: Species.CHINGLING, allowEvolution: true },
+      { species: Species.CHINGLING },
-      { species: Species.LITWICK, allowEvolution: true },
+      { species: Species.LITWICK },
-      { species: Species.CUBCHOO, allowEvolution: true },
+      { species: Species.CUBCHOO },
-      { species: Species.SWIRLIX, allowEvolution: true },
+      { species: Species.SWIRLIX },
-      { species: Species.AMAURA, allowEvolution: true },
+      { species: Species.AMAURA },
-      { species: Species.MUDBRAY, allowEvolution: true },
+      { species: Species.MUDBRAY },
-      { species: Species.ROLYCOLY, allowEvolution: true },
+      { species: Species.ROLYCOLY },
-      { species: Species.MILCERY, allowEvolution: true },
+      { species: Species.MILCERY },
-      { species: Species.SMOLIV, allowEvolution: true },
+      { species: Species.SMOLIV },
-      { species: Species.ALOLA_VULPIX, allowEvolution: true },
+      { species: Species.ALOLA_VULPIX },
-      { species: Species.GALAR_DARUMAKA, allowEvolution: true },
+      { species: Species.GALAR_DARUMAKA },
       { species: Species.IRON_BUNDLE }
     ],
     delibirdyBuff: [ "CATCHING_CHARM", "SHINY_CHARM", "ABILITY_CHARM", "EXP_CHARM", "SUPER_EXP_CHARM", "HEALING_CHARM" ],
-    weather: [{ weatherType: WeatherType.SNOW, weight: 1 }]
+    weather: [{ weatherType: WeatherType.SNOW, weight: 1 }],
+    mysteryEncounterTierChanges: [
+      { mysteryEncounter: MysteryEncounterType.DELIBIRDY, tier: MysteryEncounterTier.COMMON },
+      { mysteryEncounter: MysteryEncounterType.PART_TIMER, disable: true },
+      { mysteryEncounter: MysteryEncounterType.AN_OFFER_YOU_CANT_REFUSE, disable: true },
+      { mysteryEncounter: MysteryEncounterType.FIELD_TRIP, disable: true },
+      { mysteryEncounter: MysteryEncounterType.DEPARTMENT_STORE_SALE, disable: true }
+    ]
+  },
+  {
+    name: "Year of the Snake",
+    eventType: EventType.LUCK,
+    luckBoost: 1,
+    startDate: new Date(Date.UTC(2025, 0, 29, 0)),
+    endDate: new Date(Date.UTC(2025, 1, 3, 0)),
+    bannerKey: "yearofthesnakeevent-",
+    scale: 0.21,
+    availableLangs: [],
+    eventEncounters: [
+      { species: Species.EKANS },
+      { species: Species.ONIX },
+      { species: Species.DRATINI },
+      { species: Species.CLEFFA },
+      { species: Species.UMBREON },
+      { species: Species.DUNSPARCE },
+      { species: Species.TEDDIURSA },
+      { species: Species.SEVIPER },
+      { species: Species.LUNATONE },
+      { species: Species.CHINGLING },
+      { species: Species.SNIVY },
+      { species: Species.DARUMAKA },
+      { species: Species.DRAMPA },
+      { species: Species.SILICOBRA },
+      { species: Species.BLOODMOON_URSALUNA }
+    ],
+    luckBoostedSpecies: [
+      Species.EKANS, Species.ARBOK,
+      Species.ONIX, Species.STEELIX,
+      Species.DRATINI, Species.DRAGONAIR, Species.DRAGONITE,
+      Species.CLEFFA, Species.CLEFAIRY, Species.CLEFABLE,
+      Species.UMBREON,
+      Species.DUNSPARCE, Species.DUDUNSPARCE,
+      Species.TEDDIURSA, Species.URSARING, Species.URSALUNA,
+      Species.SEVIPER,
+      Species.LUNATONE,
+      Species.RAYQUAZA,
+      Species.CHINGLING, Species.CHIMECHO,
+      Species.CRESSELIA,
+      Species.DARKRAI,
+      Species.SNIVY, Species.SERVINE, Species.SERPERIOR,
+      Species.DARUMAKA, Species.DARMANITAN,
+      Species.ZYGARDE,
+      Species.DRAMPA,
+      Species.LUNALA,
+      Species.BLACEPHALON,
+      Species.SILICOBRA, Species.SANDACONDA,
+      Species.ROARING_MOON,
+      Species.BLOODMOON_URSALUNA
+    ]
   }
 ];
 
@@ -97,16 +170,6 @@ export class TimedEventManager {
     return activeEvents.length > 0;
   }
 
-  getFriendshipMultiplier(): number {
-    let multiplier = 1;
-    const friendshipEvents = timedEvents.filter((te) => this.isActive(te));
-    friendshipEvents.forEach((fe) => {
-      multiplier *= fe.friendshipMultiplier ?? 1;
-    });
-
-    return multiplier;
-  }
-
   getShinyMultiplier(): number {
     let multiplier = 1;
     const shinyEvents = timedEvents.filter((te) => te.eventType === EventType.SHINY && this.isActive(te));
@@ -120,6 +183,120 @@ export class TimedEventManager {
   getEventBannerFilename(): string {
     return timedEvents.find((te: TimedEvent) => this.isActive(te))?.bannerKey ?? "";
   }
+
+  getEventEncounters(): EventEncounter[] {
+    const ret: EventEncounter[] = [];
+    timedEvents.filter((te) => this.isActive(te)).map((te) => {
+      if (!isNullOrUndefined(te.eventEncounters)) {
+        ret.push(...te.eventEncounters);
+      }
+    });
+    return ret;
+  }
+
+  /**
+   * For events that change the classic candy friendship multiplier
+   * @returns The highest classic friendship multiplier among the active events, or the default CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER
+   */
+  getClassicFriendshipMultiplier(): number {
+    let multiplier = CLASSIC_CANDY_FRIENDSHIP_MULTIPLIER;
+    const classicFriendshipEvents = timedEvents.filter((te) => this.isActive(te));
+    classicFriendshipEvents.forEach((fe) => {
+      if (!isNullOrUndefined(fe.classicFriendshipMultiplier) && fe.classicFriendshipMultiplier > multiplier) {
+        multiplier = fe.classicFriendshipMultiplier;
+      }
+    });
+    return multiplier;
+  }
+
+  /**
+   * For events where defeated bosses (Gym Leaders, E4 etc) give out Voucher Plus even if they were defeated before
+   * @returns Whether vouchers should be upgraded
+   */
+  getUpgradeUnlockedVouchers(): boolean {
+    return timedEvents.some((te) => this.isActive(te) && (te.upgradeUnlockedVouchers ?? false));
+  }
+
+  /**
+   * For events where Delibirdy gives extra items
+   * @returns list of ids of {@linkcode ModifierType}s that Delibirdy hands out as a bonus
+   */
+  getDelibirdyBuff(): string[] {
+    const ret: string[] = [];
+    timedEvents.filter((te) => this.isActive(te)).map((te) => {
+      if (!isNullOrUndefined(te.delibirdyBuff)) {
+        ret.push(...te.delibirdyBuff);
+      }
+    });
+    return ret;
+  }
+
+  /**
+   * For events where there's a set weather for town biome (other biomes are hard)
+   * @returns Event weathers for town
+   */
+  getWeather(): WeatherPoolEntry[] {
+    const ret: WeatherPoolEntry[] = [];
+    timedEvents.filter((te) => this.isActive(te)).map((te) => {
+      if (!isNullOrUndefined(te.weather)) {
+        ret.push(...te.weather);
+      }
+    });
+    return ret;
+  }
+
+  getAllMysteryEncounterChanges(): EventMysteryEncounterTier[] {
+    const ret: EventMysteryEncounterTier[] = [];
+    timedEvents.filter((te) => this.isActive(te)).map((te) => {
+      if (!isNullOrUndefined(te.mysteryEncounterTierChanges)) {
+        ret.push(...te.mysteryEncounterTierChanges);
+      }
+    });
+    return ret;
+  }
+
+  getEventMysteryEncountersDisabled(): MysteryEncounterType[] {
+    const ret: MysteryEncounterType[] = [];
+    timedEvents.filter((te) => this.isActive(te) && !isNullOrUndefined(te.mysteryEncounterTierChanges)).map((te) => {
+      te.mysteryEncounterTierChanges?.map((metc) => {
+        if (metc.disable) {
+          ret.push(metc.mysteryEncounter);
+        }
+      });
+    });
+    return ret;
+  }
+
+  getMysteryEncounterTierForEvent(encounterType: MysteryEncounterType, normal: MysteryEncounterTier): MysteryEncounterTier {
+    let ret = normal;
+    timedEvents.filter((te) => this.isActive(te) && !isNullOrUndefined(te.mysteryEncounterTierChanges)).map((te) => {
+      te.mysteryEncounterTierChanges?.map((metc) => {
+        if (metc.mysteryEncounter === encounterType) {
+          ret = metc.tier ?? normal;
+        }
+      });
+    });
+    return ret;
+  }
+
+  getEventLuckBoost(): number {
+    let ret = 0;
+    const luckEvents = timedEvents.filter((te) => this.isActive(te) && !isNullOrUndefined(te.luckBoost));
+    luckEvents.forEach((le) => {
+      ret += le.luckBoost!;
+    });
+    return ret;
+  }
+
+  getEventLuckBoostedSpecies(): Species[] {
+    const ret: Species[] = [];
+    timedEvents.filter((te) => this.isActive(te)).map((te) => {
+      if (!isNullOrUndefined(te.luckBoostedSpecies)) {
+        ret.push(...te.luckBoostedSpecies.filter(s => !ret.includes(s)));
+      }
+    });
+    return ret;
+  }
 }
 
 export class TimedEventDisplay extends Phaser.GameObjects.Container {