From 1ca5b23f19da951893a83123eae1b99329e80ca9 Mon Sep 17 00:00:00 2001
From: Pawkkie <61265402+Pawkkie@users.noreply.github.com>
Date: Mon, 22 Sep 2025 13:47:23 -0400
Subject: [PATCH] Fix abusable two-turn-move switch behaviour (#7770)

---
 include/config/ai.h           |  2 +-
 src/battle_ai_switch_items.c  |  3 ++-
 test/battle/ai/ai_switching.c | 10 +++++-----
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/include/config/ai.h b/include/config/ai.h
index 877b3da427..b834829edf 100644
--- a/include/config/ai.h
+++ b/include/config/ai.h
@@ -15,7 +15,7 @@
 #define SHOULD_SWITCH_ABSORBS_MOVE_PERCENTAGE                       100
 #define SHOULD_SWITCH_ABSORBS_HIDDEN_POWER_PERCENTAGE               50
 #define SHOULD_SWITCH_TRAPPER_PERCENTAGE                            100
-#define SHOULD_SWITCH_FREE_TURN_PERCENTAGE                          100
+#define SHOULD_SWITCH_FREE_TURN_PERCENTAGE                          50
 #define STAY_IN_ABSORBING_PERCENTAGE                                66  // Chance to stay in if outgoing mon has super effective move against player, will prevent switching out for an absorber with this likelihood
 #define SHOULD_SWITCH_HASBADODDS_PERCENTAGE                         50
 #define SHOULD_SWITCH_ENCORE_STATUS_PERCENTAGE                      100
diff --git a/src/battle_ai_switch_items.c b/src/battle_ai_switch_items.c
index 6340b921c6..391b40af98 100644
--- a/src/battle_ai_switch_items.c
+++ b/src/battle_ai_switch_items.c
@@ -621,6 +621,7 @@ static bool32 ShouldSwitchIfOpponentChargingOrInvulnerable(u32 battler)
     if (IsDoubleBattle() || !(gAiThinkingStruct->aiFlags[battler] & AI_FLAG_SMART_SWITCHING))
         return FALSE;
 
+    // In a world with a unified ShouldSwitch function, also want to check whether we already win 1v1 and if we do don't switch; not worth doubling the HasBadOdds computation for now
     if (isOpposingBattlerChargingOrInvulnerable && gAiLogicData->mostSuitableMonId[battler] != PARTY_SIZE && RandomPercentage(RNG_AI_SWITCH_FREE_TURN, GetSwitchChance(SHOULD_SWITCH_FREE_TURN)))
         return SetSwitchinAndSwitch(battler, PARTY_SIZE);
 
@@ -658,7 +659,7 @@ static bool32 ShouldSwitchIfTrapperInParty(u32 battler)
         if (CanAbilityTrapOpponent(monAbility, opposingBattler) || (CanAbilityTrapOpponent(gAiLogicData->abilities[opposingBattler], opposingBattler) && monAbility == ABILITY_TRACE))
         {
             // If mon in slot i is the most suitable switchin candidate, then it's a trapper than wins 1v1
-            if (i == gAiLogicData->mostSuitableMonId[battler] && RandomPercentage(RNG_AI_SWITCH_FREE_TURN, GetSwitchChance(SHOULD_SWITCH_FREE_TURN)))
+            if (i == gAiLogicData->mostSuitableMonId[battler] && RandomPercentage(RNG_AI_SWITCH_TRAPPER, GetSwitchChance(SHOULD_SWITCH_TRAPPER)))
                 return SetSwitchinAndSwitch(battler, PARTY_SIZE);
         }
     }
diff --git a/test/battle/ai/ai_switching.c b/test/battle/ai/ai_switching.c
index b1aad9afb2..f6d7304a6b 100644
--- a/test/battle/ai/ai_switching.c
+++ b/test/battle/ai/ai_switching.c
@@ -748,15 +748,15 @@ AI_DOUBLE_BATTLE_TEST("AI_FLAG_SMART_SWITCHING: AI will switch out if it has bee
     }
 }
 
-AI_SINGLE_BATTLE_TEST("AI_FLAG_SMART_SWITCHING: AI will switch out if player's mon is semi-invulnerable and it has an absorber")
+AI_SINGLE_BATTLE_TEST("AI_FLAG_SMART_SWITCHING: AI will switch out if player's mon is semi-invulnerable and it has a good switchin")
 {
     PASSES_RANDOMLY(SHOULD_SWITCH_FREE_TURN_PERCENTAGE, 100, RNG_AI_SWITCH_FREE_TURN);
     GIVEN {
         ASSUME(GetMoveType(MOVE_DIVE) == TYPE_WATER);
-        AI_FLAGS(AI_FLAG_CHECK_BAD_MOVE | AI_FLAG_CHECK_VIABILITY | AI_FLAG_TRY_TO_FAINT | AI_FLAG_SMART_SWITCHING);
-        PLAYER(SPECIES_LUVDISC) { Moves(MOVE_DIVE); }
+        AI_FLAGS(AI_FLAG_CHECK_BAD_MOVE | AI_FLAG_CHECK_VIABILITY | AI_FLAG_TRY_TO_FAINT | AI_FLAG_SMART_SWITCHING | AI_FLAG_SMART_MON_CHOICES);
+        PLAYER(SPECIES_LUVDISC) { Level(1); Moves(MOVE_DIVE); }
         OPPONENT(SPECIES_ZIGZAGOON) { Moves(MOVE_SCRATCH); }
-        OPPONENT(SPECIES_MANTINE) { Moves(MOVE_SCRATCH); Ability(ABILITY_WATER_ABSORB); }
+        OPPONENT(SPECIES_PIKACHU) { Moves(MOVE_THUNDERBOLT); }
     } WHEN {
         TURN { MOVE(player, MOVE_DIVE) ; EXPECT_MOVE(opponent, MOVE_SCRATCH); }
         TURN { SKIP_TURN(player); EXPECT_SWITCH(opponent, 1); }
@@ -810,7 +810,7 @@ AI_SINGLE_BATTLE_TEST("AI_FLAG_SMART_SWITCHING: AI will switch out if player's m
 
 AI_SINGLE_BATTLE_TEST("AI_FLAG_SMART_SWITCHING: AI will switch out if player's mon is charging and it has a good switchin immunity (ability)")
 {
-    PASSES_RANDOMLY(SHOULD_SWITCH_FREE_TURN_PERCENTAGE, 100, RNG_AI_SWITCH_FREE_TURN);
+    PASSES_RANDOMLY(SHOULD_SWITCH_ABSORBS_MOVE_PERCENTAGE, 100, RNG_AI_SWITCH_ABSORBING);
     GIVEN {
         ASSUME(GetMoveType(MOVE_DIG) == TYPE_GROUND);
         AI_FLAGS(AI_FLAG_CHECK_BAD_MOVE | AI_FLAG_CHECK_VIABILITY | AI_FLAG_TRY_TO_FAINT | AI_FLAG_SMART_SWITCHING);