From b1128738e5a7c1a73c86292ca2673a7c948f266e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Bastos=20Dias?=
 <80102738+andrebastosdias@users.noreply.github.com>
Date: Tue, 7 Jan 2025 06:22:33 +0000
Subject: [PATCH] Fix: [Gen 1] Substitute + Confusion interaction

---
 sim/battle.ts | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/sim/battle.ts b/sim/battle.ts
index dba8f006b52c..294a7113acbf 100644
--- a/sim/battle.ts
+++ b/sim/battle.ts
@@ -2043,13 +2043,15 @@ export class Battle {
 			this.lastDamage = damage;
 			if (target.volatiles['substitute']) {
 				const hint = "In Gen 1, if a Pokemon with a Substitute hurts itself due to confusion or Jump Kick/Hi Jump Kick recoil and the target";
-				if (source?.volatiles['substitute']) {
-					source.volatiles['substitute'].hp -= damage;
-					if (source.volatiles['substitute'].hp <= 0) {
-						source.removeVolatile('substitute');
-						source.subFainted = true;
+				// if the move was a self-targeting move, the source is the same as the target. We need the check the opposing substitute
+				const foe = target.side.foe.active[0];
+				if (foe?.volatiles['substitute']) {
+					foe.volatiles['substitute'].hp -= damage;
+					if (foe.volatiles['substitute'].hp <= 0) {
+						foe.removeVolatile('substitute');
+						foe.subFainted = true;
 					} else {
-						this.add('-activate', source, 'Substitute', '[damage]');
+						this.add('-activate', foe, 'Substitute', '[damage]');
 					}
 					this.hint(hint + " has a Substitute, the target's Substitute takes the damage.");
 					return damage;