diff --git a/tools/balance/sim-balance.mjs b/tools/balance/sim-balance.mjs
index c783ac6..789f074 100644
--- a/tools/balance/sim-balance.mjs
+++ b/tools/balance/sim-balance.mjs
@@ -423,6 +423,9 @@ export function simulateCombat(data, rng, stats) {
         const hitN = (c.hits || 1) + bonusHits;
         let useAoe = c.aoe === true;
         if (c.class === 'shiv' && shivAoeThisCombat === true) useAoe = true;
+        if (c.class === 'shiv' && !shivFirstDamageBonusUsed && powerFieldTotal('firstShivDamageBonus') > 0) {
+          shivFirstDamageBonusUsed = true;
+        }
         const perHit = calcAttack(baseDamage || 0, pStr, pWeak, 0) * turnAttackMultiplier;
         const dealToTarget = (target, amount) => {
           if (!target || !target.alive) return { killed: false, dealt: 0 };
@@ -516,9 +519,6 @@ export function simulateCombat(data, rng, stats) {
           }
         }
         }
-        if (c.class === 'shiv' && !shivFirstDamageBonusUsed && powerFieldTotal('firstShivDamageBonus') > 0) {
-          shivFirstDamageBonusUsed = true;
-        }
       }
     }
     if (c.strength) pStr += c.strength;
diff --git a/tools/balance/sim-balance.test.mjs b/tools/balance/sim-balance.test.mjs
index fe44e5e..3583a11 100644
--- a/tools/balance/sim-balance.test.mjs
+++ b/tools/balance/sim-balance.test.mjs
@@ -902,6 +902,22 @@ test("calcEnemyAttack: 힘 손실이 base 아래로 공격을 낮춘다 (음수
   assert.equal(calcEnemyAttack(5, 0, 0, 0, 6), 0); // 5-6=-1 → 0 클램프
 });
 
+test('simulateCombat: firstShivDamageBonus는 턴당 첫 Shiv에만 적용 (Lua 동기화)', () => {
+  // PhantomBlades(firstShivDamageBonus 9) 활성. 턴당 3 Shiv 사용(에너지3·cost1).
+  // 정답(첫 Shiv만 +9): 턴1 = 10+1+1=12 → 13HP에 1 남김 → 2턴.
+  // 버그(모든 Shiv +9): 턴1 = 10*3=30 → 1턴.
+  const data = {
+    cards: {
+      PhantomBlades: { name: '환영검', cost: 0, kind: 'Power', firstShivDamageBonus: 9 },
+      Shiv: { name: '시브', cost: 1, kind: 'Attack', class: 'shiv', damage: 1 },
+    },
+    starterDeck: ['PhantomBlades', 'Shiv', 'Shiv', 'Shiv', 'Shiv'],
+    monsters: [{ name: '적', maxHp: 13, intents: [{ kind: 'Attack', value: 0 }] }],
+  };
+  const r = simulateCombat(data, mulberry32(1));
+  assert.equal(r.turns, 2);
+});
+
 test("simulateCombat: repeatOnKill repeats an attack until no kill occurs", () => {
   const shared = {
     cards: {