[balance] Training session ME does not update Seen/Defeated GameStats

src/data/mystery-encounters/encounters/training-session-encounter.ts

@@ -37,6 +37,7 @@ export const TrainingSessionEncounter: MysteryEncounter =
     .withScenePartySizeRequirement(2, 6, true) // Must have at least 2 unfainted pokemon in party
     .withFleeAllowed(false)
     .withHideWildIntroMessage(true)
+    .withPreventGameStatsUpdates(true) // Do not count the Pokemon as seen or defeated since it is ours
     .withIntroSpriteConfigs([
       {
         spriteKey: "training_session_gear",

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

@@ -53,6 +53,7 @@ export interface IMysteryEncounter {
   hasBattleAnimationsWithoutTargets: boolean;
   skipEnemyBattleTurns: boolean;
   skipToFightInput: boolean;
+  preventGameStatsUpdates: boolean;
 
   onInit?: (scene: BattleScene) => boolean;
   onVisualsStart?: (scene: BattleScene) => boolean;
@@ -150,6 +151,10 @@ export default class MysteryEncounter implements IMysteryEncounter {
    * If true, will skip COMMAND input and go straight to FIGHT (move select) input menu
    */
   skipToFightInput: boolean;
+  /**
+   * If true, will prevent updating {@linkcode GameStats} for encountering and/or defeating Pokemon
+   */
+  preventGameStatsUpdates: boolean;
 
   // #region Event callback functions
 
@@ -548,6 +553,7 @@ export class MysteryEncounterBuilder implements Partial<IMysteryEncounter> {
   hasBattleAnimationsWithoutTargets: boolean = false;
   skipEnemyBattleTurns: boolean = false;
   skipToFightInput: boolean = false;
+  preventGameStatsUpdates: boolean = false;
   maxAllowedEncounters: number = 3;
   expMultiplier: number = 1;
 
@@ -735,6 +741,14 @@ export class MysteryEncounterBuilder implements Partial<IMysteryEncounter> {
     return Object.assign(this, { skipToFightInput });
   }
 
+  /**
+   * If true, will prevent updating {@linkcode GameStats} for encountering and/or defeating Pokemon
+   * Default `false`
+   */
+  withPreventGameStatsUpdates(preventGameStatsUpdates: boolean): this & Required<Pick<IMysteryEncounter, "preventGameStatsUpdates">> {
+    return Object.assign(this, { preventGameStatsUpdates });
+  }
+
   /**
    * Sets the maximum number of times that an encounter can spawn in a given Classic run
    * @param maxAllowedEncounters

src/phases/victory-phase.ts

@@ -25,12 +25,17 @@ export class VictoryPhase extends PokemonPhase {
   start() {
     super.start();
 
+    const isMysteryEncounter = this.scene.currentBattle.isBattleMysteryEncounter();
+
+    // update Pokemon defeated count except for MEs that disable it
+    if (!isMysteryEncounter || !this.scene.currentBattle.mysteryEncounter?.preventGameStatsUpdates) {
       this.scene.gameData.gameStats.pokemonDefeated++;
+    }
 
     const expValue = this.getPokemon().getExpValue();
     this.scene.applyPartyExp(expValue, true);
 
-    if (this.scene.currentBattle.isBattleMysteryEncounter()) {
+    if (isMysteryEncounter) {
       handleMysteryEncounterVictory(this.scene, false, this.isExpOnly);
       return this.end();
     }

src/system/game-data.ts

@@ -1569,6 +1569,10 @@ export class GameData {
   }
 
   setPokemonSeen(pokemon: Pokemon, incrementCount: boolean = true, trainer: boolean = false): void {
+    // Some Mystery Encounters block updates to these stats
+    if (this.scene.currentBattle?.isBattleMysteryEncounter() && this.scene.currentBattle.mysteryEncounter?.preventGameStatsUpdates) {
+      return;
+    }
     const dexEntry = this.dexData[pokemon.species.speciesId];
     dexEntry.seenAttr |= pokemon.getDexAttr();
     if (incrementCount) {