Implemented Triple Arrows' effect

data/battle_scripts_1.s

@@ -423,6 +423,11 @@ gBattleScriptsForMoveEffects::
 	.4byte BattleScript_EffectHitSetEntryHazard       @ EFFECT_HIT_SET_ENTRY_HAZARD
 	.4byte BattleScript_EffectDireClaw                @ EFFECT_DIRE_CLAW
 	.4byte BattleScript_EffectBarbBarrage             @ EFFECT_BARB_BARRAGE
+	.4byte BattleScript_EffectTripleArrows            @ EFFECT_TRIPLE_ARROWS
+
+BattleScript_EffectTripleArrows::
+	setmoveeffect MOVE_EFFECT_TRIPLE_ARROWS
+	goto BattleScript_EffectHit
 
 BattleScript_StealthRockActivates::
 	setstealthrock BattleScript_MoveEnd
@@ -1451,6 +1456,11 @@ BattleScript_DoubleShockRemoveType::
 	waitmessage B_WAIT_TIME_LONG
 	return
 
+BattleScript_DefDown::
+	modifybattlerstatstage BS_TARGET, STAT_DEF, DECREASE, 1, BattleScript_DefDown_Ret, ANIM_ON
+BattleScript_DefDown_Ret:
+	return
+
 BattleScript_EffectPurify:
 	attackcanceler
 	attackstring

include/battle_scripts.h

@@ -457,6 +457,7 @@ extern const u8 BattleScript_DampPreventsAftermath[];
 extern const u8 BattleScript_HealingWishActivates[];
 extern const u8 BattleScript_LunarDanceActivates[];
 extern const u8 BattleScript_ShellTrapSetUp[];
+extern const u8 BattleScript_DefDown[];
 extern const u8 BattleScript_CouldntFullyProtect[];
 extern const u8 BattleScript_MoveEffectStockpileWoreOff[];
 extern const u8 BattleScript_StealthRockActivates[];

include/constants/battle.h

@@ -376,8 +376,9 @@
 #define MOVE_EFFECT_DIRE_CLAW           74
 #define MOVE_EFFECT_STEALTH_ROCK        75
 #define MOVE_EFFECT_SPIKES              76
+#define MOVE_EFFECT_TRIPLE_ARROWS       77
 
-#define NUM_MOVE_EFFECTS                77
+#define NUM_MOVE_EFFECTS                78
 
 #define MOVE_EFFECT_AFFECTS_USER        0x4000
 #define MOVE_EFFECT_CERTAIN             0x8000

include/constants/battle_move_effects.h

@@ -404,7 +404,8 @@
 #define EFFECT_HIT_SET_ENTRY_HAZARD         398
 #define EFFECT_DIRE_CLAW                    399
 #define EFFECT_BARB_BARRAGE                 400
+#define EFFECT_TRIPLE_ARROWS                401
 
-#define NUM_BATTLE_MOVE_EFFECTS             401
+#define NUM_BATTLE_MOVE_EFFECTS             402
 
 #endif  // GUARD_CONSTANTS_BATTLE_MOVE_EFFECTS_H

src/battle_script_commands.c

@@ -2082,7 +2082,8 @@ s32 CalcCritChanceStage(u8 battlerAtk, u8 battlerDef, u32 move, bool32 recordAbi
                 #if B_AFFECTION_MECHANICS == TRUE
                     + 2 * (GetBattlerFriendshipScore(gBattlerAttacker) >= FRIENDSHIP_200_TO_254)
                 #endif
-                    + (abilityAtk == ABILITY_SUPER_LUCK);
+                    + (abilityAtk == ABILITY_SUPER_LUCK)
+                    + (gBattleMoves[move].effect == EFFECT_TRIPLE_ARROWS);
 
         if (critChance >= ARRAY_COUNT(sCriticalHitChance))
             critChance = ARRAY_COUNT(sCriticalHitChance) - 1;
@@ -3799,6 +3800,35 @@ void SetMoveEffect(bool32 primary, u32 certain)
                     gBattlescriptCurrInstr = BattleScript_SpikesActivates;
                 }
                 break;
+            case MOVE_EFFECT_TRIPLE_ARROWS:
+                {
+                    u32 randomChance = Random() % 100;
+                    if (randomChance < 50) // Chance to reduce a foe's Defense by 1 stat stage.
+                    {
+                        BattleScriptPush(gBattlescriptCurrInstr + 1);
+                        gBattlescriptCurrInstr = BattleScript_DefDown;
+                    }
+                    if (randomChance >= 50 && randomChance <= 80) // Chance to cause a foe to flinch.
+                    {
+                        if (battlerAbility == ABILITY_INNER_FOCUS)
+                        {
+                            if (primary == TRUE || certain == MOVE_EFFECT_CERTAIN)
+                            {
+                                gLastUsedAbility = ABILITY_INNER_FOCUS;
+                                gBattlerAbility = gEffectBattler;
+                                RecordAbilityBattle(gEffectBattler, ABILITY_INNER_FOCUS);
+                                gBattlescriptCurrInstr = BattleScript_FlinchPrevention;
+                            }
+                        }
+                        else
+                        {
+                            if (GetBattlerTurnOrderNum(gEffectBattler) > gCurrentTurnActionNumber)
+                                gBattleMons[gEffectBattler].status2 |= sStatusFlagsForMoveEffects[MOVE_EFFECT_FLINCH];
+                            gBattlescriptCurrInstr++;
+                        }
+                    }
+                }
+                break;
             }
         }
     }

src/data/battle_moves.h

@@ -12726,13 +12726,14 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_Z] =
     {
         #if B_UPDATED_MOVE_DATA >= GEN_9
             .power = 90,
+            .pp = 10,
         #else
             .power = 50,
+            .pp = 15,
         #endif
-        .effect = EFFECT_PLACEHOLDER, // EFFECT_TRIPLE_ARROWS,
+        .effect = EFFECT_TRIPLE_ARROWS,
         .type = TYPE_FIGHTING,
         .accuracy = 100,
-        .pp = 15,
         .secondaryEffectChance = 100,
         .target = MOVE_TARGET_SELECTED,
         .priority = 0,