diff --git a/Assets/GameMain/Scripts/Simulation/SimulationWorld.EnemyJobs.cs b/Assets/GameMain/Scripts/Simulation/SimulationWorld.EnemyJobs.cs
index 3711363..8fbfee7 100644
--- a/Assets/GameMain/Scripts/Simulation/SimulationWorld.EnemyJobs.cs
+++ b/Assets/GameMain/Scripts/Simulation/SimulationWorld.EnemyJobs.cs
@@ -226,9 +226,6 @@ namespace Simulation
                     RecycleInactiveProjectiles();
                 }
             }
-
-            MarkEnemyTargetSpatialIndexDirty();
-            BuildEnemyTargetSpatialIndexIfNeeded();
         }
 
         private JobHandle ExecuteEnemyMovementJob(in SimulationTickContext context)
diff --git a/Assets/GameMain/Scripts/Simulation/SimulationWorld.JobDataChannel.cs b/Assets/GameMain/Scripts/Simulation/SimulationWorld.JobDataChannel.cs
index a4b9d32..53f2207 100644
--- a/Assets/GameMain/Scripts/Simulation/SimulationWorld.JobDataChannel.cs
+++ b/Assets/GameMain/Scripts/Simulation/SimulationWorld.JobDataChannel.cs
@@ -619,9 +619,23 @@ namespace Simulation
         private void ApplyJobOutputToSimulation()
         {
             int enemyCount = Mathf.Min(_enemies.Count, _enemyJobOutputs.Length);
+            bool hasEnemyPositionChanged = false;
             for (int i = 0; i < enemyCount; i++)
             {
-                _enemies[i] = ConvertToEnemySimData(_enemyJobOutputs[i]);
+                EnemyJobOutputData output = _enemyJobOutputs[i];
+                if (!hasEnemyPositionChanged)
+                {
+                    Vector3 currentPosition = _enemies[i].Position;
+                    hasEnemyPositionChanged = currentPosition.x != output.Position.x ||
+                                              currentPosition.z != output.Position.z;
+                }
+
+                _enemies[i] = ConvertToEnemySimData(output);
+            }
+
+            if (hasEnemyPositionChanged)
+            {
+                MarkEnemyTargetSpatialIndexDirty();
             }
 
             int projectileCount = Mathf.Min(_projectiles.Count, _projectileJobOutputs.Length);
diff --git a/Assets/GameMain/Scripts/Simulation/SimulationWorld.ProjectileJobs.cs b/Assets/GameMain/Scripts/Simulation/SimulationWorld.ProjectileJobs.cs
index 8ec1748..d70d85b 100644
--- a/Assets/GameMain/Scripts/Simulation/SimulationWorld.ProjectileJobs.cs
+++ b/Assets/GameMain/Scripts/Simulation/SimulationWorld.ProjectileJobs.cs
@@ -453,7 +453,7 @@ namespace Simulation
                 return false;
             }
 
-            damage = CalculateProjectileDamage(sourceImpact.AttackBase, sourceImpact.AttackStat,
+            damage = AIUtility.CalcDamageHP(sourceImpact.AttackBase, sourceImpact.AttackStat,
                 targetImpact.DefenseStat,
                 targetImpact.DodgeStat);
             shouldDispatchPresentation = true;
@@ -537,36 +537,6 @@ namespace Simulation
             return false;
         }
 
-        private static int CalculateProjectileDamage(int attack, StatProperty attackStat, StatProperty defenseStat,
-            StatProperty dodgeStat)
-        {
-            if (dodgeStat != null)
-            {
-                if (UnityEngine.Random.value < Mathf.Clamp(dodgeStat.Percent, 0f, 0.9f))
-                {
-                    return 0;
-                }
-            }
-
-            float damage = attack;
-            if (attackStat != null)
-            {
-                damage = (attack + attackStat.Value) * attackStat.Percent;
-            }
-
-            if (defenseStat != null)
-            {
-                damage = (damage - defenseStat.Value) / defenseStat.Percent;
-            }
-
-            if (damage < 1f)
-            {
-                return 1;
-            }
-
-            return Mathf.CeilToInt(damage);
-        }
-
         private static bool TryGetTargetableEntity(int entityId, out TargetableObject target)
         {
             target = null;
diff --git a/Assets/GameMain/Scripts/Simulation/SimulationWorld.TargetSelectionSpatialIndex.cs b/Assets/GameMain/Scripts/Simulation/SimulationWorld.TargetSelectionSpatialIndex.cs
index 23c39dd..37bf518 100644
--- a/Assets/GameMain/Scripts/Simulation/SimulationWorld.TargetSelectionSpatialIndex.cs
+++ b/Assets/GameMain/Scripts/Simulation/SimulationWorld.TargetSelectionSpatialIndex.cs
@@ -8,7 +8,6 @@ namespace Simulation
     {
         private NativeParallelMultiHashMap<long, int> _enemyTargetBuckets;
         private bool _enemyTargetBucketsDirty = true;
-        private int _enemyTargetBucketsFrame = -1;
 
         [SerializeField] private float _targetSelectionCellSize = 2f;
 
@@ -85,7 +84,6 @@ namespace Simulation
 
             _enemyTargetBuckets = new NativeParallelMultiHashMap<long, int>(256, Allocator.Persistent);
             _enemyTargetBucketsDirty = true;
-            _enemyTargetBucketsFrame = -1;
         }
 
         private void DisposeEnemyTargetSpatialIndex()
@@ -97,7 +95,6 @@ namespace Simulation
 
             _enemyTargetBuckets = default;
             _enemyTargetBucketsDirty = true;
-            _enemyTargetBucketsFrame = -1;
         }
 
         private void ClearEnemyTargetSpatialIndex()
@@ -108,20 +105,18 @@ namespace Simulation
             }
 
             _enemyTargetBucketsDirty = true;
-            _enemyTargetBucketsFrame = -1;
         }
 
         private void MarkEnemyTargetSpatialIndexDirty()
         {
             _enemyTargetBucketsDirty = true;
-            _enemyTargetBucketsFrame = -1;
         }
 
         private void BuildEnemyTargetSpatialIndexIfNeeded()
         {
             InitializeEnemyTargetSpatialIndex();
 
-            if (!_enemyTargetBucketsDirty && _enemyTargetBucketsFrame == Time.frameCount)
+            if (!_enemyTargetBucketsDirty)
             {
                 return;
             }
@@ -148,7 +143,6 @@ namespace Simulation
             }
 
             _enemyTargetBucketsDirty = false;
-            _enemyTargetBucketsFrame = Time.frameCount;
         }
 
         private float GetTargetSelectionCellSize()
diff --git a/openspec/config.yaml b/openspec/config.yaml
deleted file mode 100644
index 392946c..0000000
--- a/openspec/config.yaml
+++ /dev/null
@@ -1,20 +0,0 @@
-schema: spec-driven
-
-# Project context (optional)
-# This is shown to AI when creating artifacts.
-# Add your tech stack, conventions, style guides, domain knowledge, etc.
-# Example:
-#   context: |
-#     Tech stack: TypeScript, React, Node.js
-#     We use conventional commits
-#     Domain: e-commerce platform
-
-# Per-artifact rules (optional)
-# Add custom rules for specific artifacts.
-# Example:
-#   rules:
-#     proposal:
-#       - Keep proposals under 500 words
-#       - Always include a "Non-goals" section
-#     tasks:
-#       - Break tasks into chunks of max 2 hours