diff --git a/Assets/TcgEngine/Scripts/GameClient/BoardSlot.cs b/Assets/TcgEngine/Scripts/GameClient/BoardSlot.cs
index dc6e573..9ea583f 100644
--- a/Assets/TcgEngine/Scripts/GameClient/BoardSlot.cs
+++ b/Assets/TcgEngine/Scripts/GameClient/BoardSlot.cs
@@ -57,14 +57,14 @@ namespace TcgEngine.Client
 
             //Find target opacity value
             target_alpha = 0f;
-            if (your_turn && dcard != null && dcard.CardData.IsBoardCard() && gdata.CanPlayCard(dcard, slot))
+            if (your_turn && dcard != null && dcard.CardData.IsBoardCard() && gdata.CanPlayCard(dcard, slot, true))
             {
-                target_alpha = 1f; //hightlight when dragging a character or artifact
+                target_alpha = 1f; //hightlight when dragging a character or artifact (skip mana cost)
             }
 
-            if (your_turn && dcard != null && dcard.CardData.IsRequireTarget() && gdata.CanPlayCard(dcard, slot))
+            if (your_turn && dcard != null && dcard.CardData.IsRequireTarget() && gdata.CanPlayCard(dcard, slot, true))
             {
-                target_alpha = 1f; //Highlight when dragin a spell with target
+                target_alpha = 1f; //Highlight when dragin a spell with target (skip mana cost)
             }
 
             if (gdata.selector == SelectorType.SelectTarget && player.player_id == gdata.selector_player_id)
diff --git a/Assets/TcgEngine/Scripts/GameClient/BoardSlotGroup.cs b/Assets/TcgEngine/Scripts/GameClient/BoardSlotGroup.cs
index e455f04..ad3502c 100644
--- a/Assets/TcgEngine/Scripts/GameClient/BoardSlotGroup.cs
+++ b/Assets/TcgEngine/Scripts/GameClient/BoardSlotGroup.cs
@@ -77,8 +77,8 @@ namespace TcgEngine.Client
             {
                 foreach (GroupSlot slot in group_slots)
                 {
-                    if(gdata.CanPlayCard(dcard, slot.slot))
-                        target_alpha = 1f; //hightlight when dragging a character or artifact
+                    if(gdata.CanPlayCard(dcard, slot.slot, true))
+                        target_alpha = 1f; //hightlight when dragging a character or artifact (skip mana cost)
                 }
             }
 
diff --git a/Assets/TcgEngine/Scripts/GameClient/BoardSlotPlayer.cs b/Assets/TcgEngine/Scripts/GameClient/BoardSlotPlayer.cs
index e2fca41..b1ac1dc 100644
--- a/Assets/TcgEngine/Scripts/GameClient/BoardSlotPlayer.cs
+++ b/Assets/TcgEngine/Scripts/GameClient/BoardSlotPlayer.cs
@@ -67,16 +67,17 @@ namespace TcgEngine.Client
 
             target_alpha = 0f;
             Card select_card = bcard_selected?.GetCard();
-            if (select_card != null)
-            {
-                bool can_do_attack = gdata.IsPlayerActionTurn(player) && select_card.CanAttack();
-                bool can_be_attacked = gdata.CanAttackTarget(select_card, oplayer);
+            // if (select_card != null)
+            // {
+                // bool can_do_attack = gdata.IsPlayerActionTurn(player) && select_card.CanAttack();
+                // bool can_be_attacked = gdata.CanAttackTarget(select_card, oplayer);
 
-                if (can_do_attack && can_be_attacked)
-                {
-                    target_alpha = 1f;
-                }
-            }
+                // 敌方可被攻击时高亮
+                // if (can_do_attack && can_be_attacked)
+                // {
+                //     target_alpha = 1f;
+                // }
+            //}
 
             if (your_turn && drag_card != null && drag_card.CardData.IsRequireTargetSpell() && gdata.IsPlayTargetValid(drag_card.GetCard(), GetPlayer()))
             {
diff --git a/Assets/TcgEngine/Scripts/GameClient/HandCard.cs b/Assets/TcgEngine/Scripts/GameClient/HandCard.cs
index cd3d871..985f2f3 100644
--- a/Assets/TcgEngine/Scripts/GameClient/HandCard.cs
+++ b/Assets/TcgEngine/Scripts/GameClient/HandCard.cs
@@ -231,9 +231,10 @@ namespace TcgEngine.Client
                 return;
             }
 
-            if (!player.CanPayMana(card))
+            // 检查本回合是否已经上场过场上卡牌（只有怪物牌等场上卡牌受限制）
+            if (card.CardData.IsBoardCard() && player.cards_played_this_turn >= 1)
             {
-                WarningText.ShowNoMana();
+                Debug.Log("本回合只能上场一张场上卡牌");
                 return;
             }
 
diff --git a/Assets/TcgEngine/Scripts/GameLogic/Game.cs b/Assets/TcgEngine/Scripts/GameLogic/Game.cs
index fe1086e..940284d 100644
--- a/Assets/TcgEngine/Scripts/GameLogic/Game.cs
+++ b/Assets/TcgEngine/Scripts/GameLogic/Game.cs
@@ -186,6 +186,10 @@ namespace TcgEngine
             if (target.HasStatus(StatusType.Protected) && !attacker.HasStatus(StatusType.Flying))
                 return false; //Protected by taunt
 
+            // 检查目标玩家场上是否有卡牌，如有则无法直接攻击玩家
+            if (target.cards_board.Count > 0)
+                return false; //Cannot attack player when they have cards on board
+
             return true;
         }
 
diff --git a/Assets/TcgEngine/Scripts/GameServer/GameServer.cs b/Assets/TcgEngine/Scripts/GameServer/GameServer.cs
index 0ddc637..9798111 100644
--- a/Assets/TcgEngine/Scripts/GameServer/GameServer.cs
+++ b/Assets/TcgEngine/Scripts/GameServer/GameServer.cs
@@ -303,7 +303,18 @@ namespace TcgEngine.Server
             {
                 Card card = player.GetCard(msg.card_uid);
                 if (card != null && card.player_id == player.player_id)
+                {
+                    // 检查本回合是否已经上场过场上卡牌（只有怪物牌等场上卡牌受限制）
+                    if (card.CardData.IsBoardCard() && player.cards_played_this_turn >= 1)
+                        return; // 已经上场过场上卡牌，不能再上场
+                    
+                    // 手动上场卡牌：跳过mana消耗
+                    // gameplay.PlayCard(card, msg.slot, true);
                     gameplay.PlayCard(card, msg.slot);
+                    // 只有场上卡牌才增加计数
+                    if (card.CardData.IsBoardCard())
+                        player.cards_played_this_turn++;
+                }
             }
         }
 
diff --git a/Assets/TcgEngine/Scripts/UI/IconBar.cs b/Assets/TcgEngine/Scripts/UI/IconBar.cs
index afa4ea2..cf81c6c 100644
--- a/Assets/TcgEngine/Scripts/UI/IconBar.cs
+++ b/Assets/TcgEngine/Scripts/UI/IconBar.cs
@@ -33,9 +33,15 @@ namespace TcgEngine.UI
 
         public void Refresh()
         {
+            if (icons == null)
+                return;
+                
             int index = 0;
             foreach (Image icon in icons)
             {
+                if (icon == null)
+                    continue;
+                    
                 icon.gameObject.SetActive(index < value || index < max_value);
                 icon.sprite = (index < value) ? sprite_full : sprite_empty;
                 index++;
@@ -44,9 +50,13 @@ namespace TcgEngine.UI
 
         public void SetMat(Material mat)
         {
+            if (icons == null)
+                return;
+                
             foreach (Image icon in icons)
             {
-                icon.material = mat;
+                if (icon != null)
+                    icon.material = mat;
             }
         }
     }