diff --git a/.gitignore b/.gitignore
index 7ecfc1a..18d9ddc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@ bin/
 *.sln
 *.error
 *.key*
+.editorconfig
 
 # cs project files
 !*.csproj
diff --git a/Chinese_Chess.csproj b/ChessGame.csproj
similarity index 55%
rename from Chinese_Chess.csproj
rename to ChessGame.csproj
index 1748c47..1f476de 100644
--- a/Chinese_Chess.csproj
+++ b/ChessGame.csproj
@@ -1,8 +1,6 @@
 <Project Sdk="Godot.NET.Sdk/4.3.0">
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
-    <TargetFramework Condition=" '$(GodotTargetPlatform)' == 'android' ">net7.0</TargetFramework>
-    <TargetFramework Condition=" '$(GodotTargetPlatform)' == 'ios' ">net8.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <EnableDynamicLoading>true</EnableDynamicLoading>
 
     <Nullable>enable</Nullable>
diff --git a/Scripts/Controllers/ChessGame.cs b/Scripts/Controllers/ChessGame.cs
index b6de100..ac7bdc9 100644
--- a/Scripts/Controllers/ChessGame.cs
+++ b/Scripts/Controllers/ChessGame.cs
@@ -1,3 +1,4 @@
+#nullable disable
 using Godot;
 using Godot.Collections;
 using ChineseChess;
@@ -39,15 +40,15 @@ public partial class ChessGame : Node2D {
 			sideOpposite = ChessCore.TurnsSideType.Red;
 		}
 
-		if (isSession) {
-			Game = new(ChessCore.Mode.MultiMode, sideSelf);
-		} else {
-			Game = new(ChessCore.Mode.SingleMode, sideSelf);
-		}
-		board.LoadBoard(Game.board);
+		// if (isSession) {
+		// 	Game = new(ChessCore.Mode.MultiMode, sideSelf);
+		// } else {
+		// 	Game = new(ChessCore.Mode.SingleMode, sideSelf);
+		// }
+		Game = new(isSession ? ChessCore.Mode.MultiMode : ChessCore.Mode.SingleMode, sideSelf, board);
 		Game.Init();
 
-		Game.board.OnStepsChanged += (sender, e) => {
+		board.OnStepsChanged += (sender, e) => {
 			turnSideEdit.Text = Game.GetTurnsType() == ChessCore.TurnsSideType.Red ? "red" : "black";
 		};
 
diff --git a/Scripts/Controllers/GameLobby.cs b/Scripts/Controllers/GameLobby.cs
index bb7f53c..4f6fc37 100644
--- a/Scripts/Controllers/GameLobby.cs
+++ b/Scripts/Controllers/GameLobby.cs
@@ -1,3 +1,4 @@
+#nullable disable
 using Godot;
 using Godot.Collections;
 
diff --git a/Scripts/Entities/ChessBoard.cs b/Scripts/Entities/ChessBoard.cs
index 83f8219..443a925 100644
--- a/Scripts/Entities/ChessBoard.cs
+++ b/Scripts/Entities/ChessBoard.cs
@@ -4,12 +4,14 @@ using Godot;
 using ChineseChess;
 using Godot.Collections;
 
-public partial class ChessBoard : Node2D {
-    public event EventHandler<Vector2> OnMouseClicked;
-	public event EventHandler<Vector2> OnPosClicked;
+using static IBoard;
+public partial class ChessBoard : Node2D, ICCBoardOn {
+    public event EventHandler<Vector2>? OnMouseClicked;
+	public event EventHandler<Vector2>? OnPosClicked;
+	public event EventHandler<int>? OnStepsChanged;
 
 	public Vector2 from = Vector2.Inf, to = Vector2.Inf;
-	public Array<Vector2> canMovePos = new();
+	public Array<Vector2> canMovePos = [];
 
 	public override void _Ready() {
 	}
@@ -19,29 +21,39 @@ public partial class ChessBoard : Node2D {
 		QueueRedraw();
 	}
 
-	public void LoadBoard(CCBoard board) {
-		board.OnRemove += (sender, piece) => {
-			if (piece?.Data.TryGetValue("Godot", out object node) ?? false) {
-				RemoveChild(node as Node);
-			}
-		};
+	void IBoardOn.OnInsert(object self, IPiece piece) {
+		ChessPiece? node = piece.On as ChessPiece;
+        // throw new InvalidOperationException();
+        node ??= new ChessPiece((CCPiece)piece);
+		node.ShowBehindParent = true;
+        AddChild(node);
 
-		board.OnInsert += (sender, piece) => {
-			ChessPiece chessPiece = null;
-			if (piece.Data.TryGetValue("Godot", out object node)) {
-				chessPiece = node as ChessPiece;
-			} else {
-				chessPiece = new((CCPiece)piece);
-			}
-			chessPiece.ShowBehindParent = true;
-			AddChild(chessPiece);
-		};
+			// ChessPiece chessPiece = null;
+			// if (piece.Data.TryGetValue("Godot", out object node)) {
+			// 	chessPiece = node as ChessPiece;
+			// } else {
+			// 	chessPiece = new((CCPiece)piece);
+			// }
+			// chessPiece.ShowBehindParent = true;
+			// AddChild(chessPiece);
+	}
 
-		board.OnMove += (sender, vals) => {
-			from = PosTrans.transArrToPix * new Vector2(vals.From.X, vals.From.Y);
-			to = PosTrans.transArrToPix * new Vector2(vals.To.X, vals.To.Y);
-			QueueRedraw();
-		};
+	void IBoardOn.OnRemove(object self, IPiece piece) {
+		if (piece.On is not ChessPiece node) {
+			throw new InvalidOperationException();
+		}
+		RemoveChild(node);
+	}
+
+	void IBoardOn.OnMove(object self, IBoardOn.MoveEventArgs vals) {
+		from = PosTrans.transArrToPix * new Vector2(vals.From.X, vals.From.Y);
+		to = PosTrans.transArrToPix * new Vector2(vals.To.X, vals.To.Y);
+		QueueRedraw();
+	}
+
+	void ICCBoardOn.OnSteps(object _self, int oldSteps) {
+		if (_self is not CCBoard self) return;
+		OnStepsChanged?.Invoke(self, self.Steps);
 	}
 
 	public override void _Draw() {
diff --git a/Scripts/Entities/ChessPiece.cs b/Scripts/Entities/ChessPiece.cs
index 8b18863..137996e 100644
--- a/Scripts/Entities/ChessPiece.cs
+++ b/Scripts/Entities/ChessPiece.cs
@@ -4,37 +4,31 @@ using ChineseChess;
 using System.Linq;
 using System;
 
-public partial class ChessPiece : Sprite2D {
+using static IPiece;
+public partial class ChessPiece : Sprite2D, IPieceOn {
     [Export]
-    public string PieceLabel { get; set; } = null;
+    public string? PieceLabel { get; set; } = null;
     // Text Color (Can Export for Editor Adjust)
     [Export]
     public Color LabelColor { get; set; } = new Color("white");
     private Vector2 textureSize;
+    private Label? labelOfChessName;
 
-    private Label labelOfChessName;
-    private readonly IPiece piece;
-
-    public IPiece GetVirtualPiece() {
-        return piece;
-    }
-
-    private void OnPos(object _self, Vector.Vector2I oldPos) {
-        CCPiece self = (CCPiece)_self;
+    void IPieceOn.OnPos(object _self, Vector.Vector2I oldPos) {
+        if (_self is not CCPiece self) return;
         Position = ChessBoard.PosTrans.transArrToPix * new Vector2(self.Pos.X, self.Pos.Y);
     }
 
-    public void OnSelected(object _self, bool oldIsSelected) {
-        CCPiece self = (CCPiece)_self;
-        ChessBoard chessBoard = GetParent() as ChessBoard;
+    void IPieceOn.OnSelected(object _self, bool oldIsSelected) {
+        if (GetParent() is not ChessBoard chessBoard || _self is not CCPiece self) return;
         if (self.IsSelected) {
-            GD.Print($"{piece.Pos} is selected");
+            GD.Print($"{self.Pos} is selected");
             Transform *= transToSeleted;
             foreach (var item in self.CanMoveAllPos()) {
                 chessBoard.canMovePos.Add(ChessBoard.PosTrans.transArrToPix * new Vector2(item.X, item.Y));
             }
         } else {
-            GD.Print($"{piece.Pos} is deselected");
+            GD.Print($"{self.Pos} is deselected");
             Transform *= transToSeleted.AffineInverse();
             foreach (var item in self.CanMoveAllPos()) {
                 chessBoard.canMovePos.Remove(ChessBoard.PosTrans.transArrToPix * new Vector2(item.X, item.Y));
@@ -49,17 +43,15 @@ public partial class ChessPiece : Sprite2D {
 		new Vector2(0, 0)
 	);
 
-    public ChessPiece() : this(new CCPiece()){
+    public ChessPiece() : this(new CCPiece()) {
     }
 
     public ChessPiece(CCPiece piece) {
         PieceLabel = piece.CNName;
-        this.piece = piece;
         LabelColor = piece.TurnsSide == ChessCore.TurnsSideType.Red ? new Color("red") : new Color("black");
-        piece.OnPos +=  OnPos;
-        piece.OnSelected += OnSelected;
+        piece.On = this;
         // Must Be Call for init Pos
-        OnPos(piece, piece.Pos);
+        piece.On.OnPos(piece, piece.Pos);
         piece.Data.TryAdd("Godot", this);
     }
 
diff --git a/Scripts/Global.cs b/Scripts/Global.cs
index 082881e..2ebebfb 100644
--- a/Scripts/Global.cs
+++ b/Scripts/Global.cs
@@ -1,15 +1,15 @@
+#nullable disable
 using System.Collections.Generic;
 using Godot;
 using RPPackage;
 
-public partial class Global : Node
-{
+public partial class Global : Node {
 	public RPClientEDWS RPClient = new();
 	public string sessionId;
 	public Node CurrentScene { get; set; }
 	public Theme GlobalTheme = null;
 
-    readonly GodotConfigManager GlobalConfig = new("user://config.cfg");
+	readonly GodotConfigManager GlobalConfig = new("user://config.cfg");
 	public Dictionary<string, Variant> GlobalConfigDict = new() {
 		{"font_size", 20},
 		{"server_url", "wss://game.zzyxyz.com/"},
@@ -21,8 +21,7 @@ public partial class Global : Node
 	};
 
 	// Called when the node enters the scene tree for the first time.
-	public override void _Ready()
-	{
+	public override void _Ready() {
 		if (OS.GetName() == "Android") {
 			bool ret = OS.RequestPermissions();
 			GD.Print($"RequestPermissions ret is {ret}");
@@ -37,41 +36,36 @@ public partial class Global : Node
 		};
 
 		Viewport root = GetTree().Root;
-        CurrentScene = root.GetChild(root.GetChildCount() - 1);
+		CurrentScene = root.GetChild(root.GetChildCount() - 1);
 
 		GlobalConfig.LoadConfig("Global", GlobalConfigDict);
 		SetProcess(false);
 	}
 
-	public void ConfigFlush()
-	{
+	public void ConfigFlush() {
 		int font_size = (int)GlobalConfigDict["font_size"];
 		GlobalTheme.DefaultFontSize = font_size;
 		// GlobalTheme?.SetFontSize("font_size", "Label",    font_size);
-        // GlobalTheme?.SetFontSize("font_size", "Button",   font_size);
-        // GlobalTheme?.SetFontSize("font_size", "TextEdit", font_size);
-        // GlobalTheme?.SetFontSize("font_size", "LineEdit", font_size);
+		// GlobalTheme?.SetFontSize("font_size", "Button",   font_size);
+		// GlobalTheme?.SetFontSize("font_size", "TextEdit", font_size);
+		// GlobalTheme?.SetFontSize("font_size", "LineEdit", font_size);
 		// CurrentScene.GetWindow().AddThemeFontSizeOverride("Control", (int)GlobalConfigDict["font_size"]);
 	}
 
-	private void OnGotoScene()
-	{
+	private void OnGotoScene() {
 		ConfigFlush();
 	}
 
-	public void SaveConfig()
-	{
+	public void SaveConfig() {
 		GlobalConfig.SaveConfig("Global", GlobalConfigDict);
 	}
 
 	// Called every frame. 'delta' is the elapsed time since the previous frame.
-	public override void _Process(double delta)
-	{
+	public override void _Process(double delta) {
 		RPClient.PollEx(delta);
 	}
 
-	public override void _Notification(int what)
-	{
+	public override void _Notification(int what) {
 		if (what == NotificationWMCloseRequest) {
 			// SaveConfig();
 			RPClient.Close();
@@ -81,8 +75,7 @@ public partial class Global : Node
 
 	public delegate void ChangeSceneCallback(Node newSence);
 	private static ChangeSceneCallback changeSceneCallback = null;
-	public void GotoScene(string path, ChangeSceneCallback callback = null)
-	{
+	public void GotoScene(string path, ChangeSceneCallback callback = null) {
 		// This function will usually be called from a signal callback,
 		// or some other function from the current scene.
 		// Deleting the current scene at this point is
@@ -100,8 +93,7 @@ public partial class Global : Node
 		changeSceneCallback = null;
 	}
 
-	public void DeferredGotoScene(string path, Callable onLoaded)
-	{
+	public void DeferredGotoScene(string path, Callable onLoaded) {
 		// It is now safe to remove the current scene.
 		CurrentScene.Free();
 
diff --git a/Scripts/Src/AbstractBoard.cs b/Scripts/Src/AbstractBoard.cs
index af269fd..d4bf391 100644
--- a/Scripts/Src/AbstractBoard.cs
+++ b/Scripts/Src/AbstractBoard.cs
@@ -1,32 +1,20 @@
-using System;
 using System.Collections.Generic;
 using Vector2I = Vector.Vector2I;
 
 using static IBoard;
-public abstract class AbstractBoard : IBoard {
-    private readonly int rows;
-    private readonly int cols;
-    protected readonly IPiece?[,] pieces;
-    protected readonly List<MoveRecord> moveRecords = new();
-    protected readonly int MAX_RECORDS;
+public abstract class AbstractBoard(int rows, int cols, int maxRecords = int.MaxValue,
+        IBoardOn? on = null) : IBoard {
+    private readonly int rows = rows;
+    private readonly int cols = cols;
+    protected readonly IPiece?[,] pieces = new IPiece[rows, cols];
+    protected readonly List<MoveRecord> moveRecords = [];
+    protected readonly int MAX_RECORDS = maxRecords;
 
     public int Rows => rows;
     public int Cols => cols;
+    protected IBoardOn? on = on;
 
-    public event EventHandler<SetPieceEventArgs>? OnSetPiece;
-    public event EventHandler<IPiece>? OnInsert;
-    public event EventHandler<IPiece>? OnRemove;
-    public event EventHandler<MoveEventArgs>? OnMove;
-
-    public event EventHandler<MoveRecord>? OnAddRecord;
-    public event EventHandler<MoveRecord>? OnUndoRecord;
-
-    public AbstractBoard(int rows, int cols, int maxRecords = int.MaxValue) {
-        this.rows = rows;
-        this.cols = cols;
-        pieces = new IPiece[rows, cols];
-        MAX_RECORDS = maxRecords;
-    }
+    public virtual IBoardOn? On { get => on; set => on = value; }
 
     public virtual bool IsPosOutOfRange(Vector2I arrayPos) {
         return arrayPos.X < 0 || arrayPos.X >= Rows || arrayPos.Y < 0 || arrayPos.Y >= Cols;
@@ -42,19 +30,20 @@ public abstract class AbstractBoard : IBoard {
         
         IPiece? oldPiece = pieces[pos.X, pos.Y];
         pieces[pos.X, pos.Y] = piece;
-        if (piece != null) piece.Pos = pos;
+        if (piece is not null) piece.Pos = pos;
         // if (oldPiece != null) oldPiece.Pos = Vector2I.Zero;
 
-        OnSetPiece?.Invoke(this, new SetPieceEventArgs { OldPiece = oldPiece, NewPiece = piece, Pos = pos });        
+        on?.OnSetPieceInteral(this, new IBoardOn.SetPieceEventArgs
+            (oldPiece, piece, pos));
         return oldPiece;
     }
 
     public virtual bool InsertPiece(IPiece piece, Vector2I pos) {
-        if (GetPiece(pos) != null && piece == null) {
+        if (GetPiece(pos) is not null && piece == null) {
             return false;
         }
 
-        OnInsert?.Invoke(this, piece);
+        on?.OnInsert(this, piece);
         SetPiece(piece, pos);
         return true;
     }
@@ -65,11 +54,11 @@ public abstract class AbstractBoard : IBoard {
         }
 
         IPiece? piece = GetPiece(from);
-        if (GetPiece(to) != null || piece == null) {
+        if (GetPiece(to) is not null || piece is null) {
             return false;
         }
 
-        OnMove?.Invoke(this, new MoveEventArgs { From = from, To = to, Piece = piece });
+        on?.OnMove(this, new IBoardOn.MoveEventArgs(piece, from, to));
         SetPiece(null, from);
         SetPiece(piece, to);
         return true;
@@ -77,8 +66,9 @@ public abstract class AbstractBoard : IBoard {
 
     public virtual IPiece? RemovePiece(Vector2I pos) {
         IPiece? piece = GetPiece(pos);
-        if (piece == null) return null;
-        OnRemove?.Invoke(this, piece);
+        if (piece is null) return null;
+        
+        on?.OnRemove(this, piece);
         return SetPiece(null, pos);
     }
 
@@ -103,7 +93,7 @@ public abstract class AbstractBoard : IBoard {
         }
         MoveRecord record = new(From, To, FromPos, ToPos);
 
-        OnAddRecord?.Invoke(this, record);
+        on?.OnAddRecord(this, record);
         moveRecords.Add(record);
     }
     
@@ -113,29 +103,15 @@ public abstract class AbstractBoard : IBoard {
         moveRecords.RemoveAt(moveRecords.Count - 1);
 
         // 恢复新位置的棋子，order is very inmportant
-        if (record.From != null) {
+        if (record.From is not null) {
             MovePiece(record.ToPos, record.FromPos);
         }
         
         // 恢复旧位置的棋子
-        if (record.To != null) {
+        if (record.To is not null) {
             InsertPiece(record.To, record.ToPos);
         }
 
-        OnUndoRecord?.Invoke(this, record);
-    }
-
-    public class MoveRecord {
-        public IPiece? From { get; }
-        public IPiece? To { get; }
-        public Vector2I FromPos { get; }
-        public Vector2I ToPos { get; }
-
-        public MoveRecord(IPiece? From, IPiece? To, Vector2I FromPos, Vector2I ToPos) {
-            this.From = From;
-            this.To = To;
-            this.ToPos = ToPos;
-            this.FromPos = FromPos;
-        }
+        on?.OnUndoRecord(this, record);
     }
 }
diff --git a/Scripts/Src/AbstractPiece.cs b/Scripts/Src/AbstractPiece.cs
index 4f5bbf3..1e0c935 100644
--- a/Scripts/Src/AbstractPiece.cs
+++ b/Scripts/Src/AbstractPiece.cs
@@ -1,62 +1,61 @@
-using System;
 using System.Collections.Generic;
 using Vector2I = Vector.Vector2I;
 
-public abstract class AbstractPiece : IPiece {
-    private Vector2I pos; // 注意这个坐标的非像素坐标而是棋盘坐标
+using static IPiece;
+public abstract class AbstractPiece(string name = "", Vector2I? pos = null,
+        IPieceOn? on = null) : IPiece {
+    private Vector2I pos = pos ?? new(); // 注意这个坐标的非像素坐标而是棋盘坐标
     private bool isSelected = false;
-    protected string name;
-    private Dictionary<string, object> data = new();
+    protected string name = name;
+    private Dictionary<string, object> data = [];
+    protected IPieceOn? on = on;
 
-    public Vector2I Pos {
+    public virtual IPieceOn? On { get => on; set => on = value; }
+
+    public virtual Vector2I Pos {
         get => pos;
         set {
             if (pos != value) {
                 var oldPos = pos;
                 pos = value;
-                OnPos?.Invoke(this, oldPos);
+                on?.OnPos(this, oldPos);
             }
         }
     }
 
-    public bool IsSelected {
+    public virtual bool IsSelected {
         get => isSelected;
         set {
             if (isSelected != value) {
                 var oldIsSelected = isSelected;
                 isSelected = value;
-                OnSelected?.Invoke(this, oldIsSelected);
+                on?.OnSelected(this, oldIsSelected);
             }
         }
     }
 
-    public string Name {
+    public virtual string Name {
         get => name;
         set {
             if (name != value) {
                 var oldName = name;
                 name = value;
-                OnName?.Invoke(this, oldName);
+                on?.OnName(this, oldName);
             }
         }
     }
 
-    public Dictionary<string, object> Data {
+    public virtual Dictionary<string, object> Data {
         get => data;
         set => data = value;
     }
 
-    public event EventHandler<Vector2I>? OnPos;
-    public event EventHandler<Vector2I>? OnMove;
-    public event EventHandler<bool>? OnSelected;
-    public event EventHandler<string>? OnName;
-
     public virtual bool Move(Vector2I pos) {
         if (!CanMove(pos)) {
             return false;
         }
         Pos = pos;
-        OnMove?.Invoke(this, pos);
+        on?.OnMove(this, pos);
         return true;
     }
 
@@ -65,9 +64,4 @@ public abstract class AbstractPiece : IPiece {
     public override string ToString() {
         return $"{Name} at {pos}";
     }
-
-    public AbstractPiece(string name = "", Vector2I? pos = null) {
-        this.name = name;
-        this.pos = pos ?? new();
-    }
 }
diff --git a/Scripts/Src/ChineseChess/CCBoard.cs b/Scripts/Src/ChineseChess/CCBoard.cs
index 83ba89c..fc6688a 100644
--- a/Scripts/Src/ChineseChess/CCBoard.cs
+++ b/Scripts/Src/ChineseChess/CCBoard.cs
@@ -1,24 +1,29 @@
-using System;
 using System.Collections;
 using static ChineseChess.ChessCore;
 using Vector2I = Vector.Vector2I;
 
 namespace ChineseChess;
-public class CCBoard : AbstractBoard
-{
-    public event EventHandler<int>? OnStepsChanged;
+public interface ICCBoardOn : IBoard.IBoardOn {
+    void OnSteps(object self, int oldSteps) {}
+}
+
+public class CCBoard(ICCBoardOn? on = null) : AbstractBoard(9, 10, on: on) {
     private int steps = 0;
+    protected new ICCBoardOn? on = on;
+    // public virtual IPieceOn? On { get => on; set => on = value; }
+    public new ICCBoardOn? On { get => on; set {
+        on = value; base.on = value;} }
+
     public int Steps {
         get => steps;
         protected set {
             if (steps != value) {
+                var oldSteps = steps;
                 steps = value;
-                OnStepsChanged?.Invoke(this, steps);
+                on?.OnSteps(this, oldSteps);
             }
         }
     }
-    public CCBoard() : base(9, 10) {
-    }
 
     public override void AddRecord(IPiece? From, IPiece? To, Vector2I FromPos, Vector2I ToPos) {
         base.AddRecord(From, To, FromPos, ToPos);
@@ -32,65 +37,49 @@ public class CCBoard : AbstractBoard
 
     public (ArrayList, ArrayList) InitGame() {
         Steps = 0;
-        // ArrayList blackPart = InitOnePartPieces(TurnsSideType.Black, new[] {
-        //     new CCChariot(TurnsSideType.Black, "black chariot 0", 0, 0),
-        //     ("车", 0, 0), ("马", 1, 0), ("象", 2, 0),
-        //     ("士", 3, 0), ("将", 4, 0), ("士", 5, 0),
-        //     ("象", 6, 0), ("马", 7, 0), ("车", 8, 0),
-        //     ("炮", 1, 2), ("炮", 7, 2),
-        //     ("卒", 0, 3), ("卒", 2, 3), ("卒", 4, 3), ("卒", 6, 3), ("卒", 8, 3)
-        //     });
+        ArrayList blackPart = InitOnePartPieces(TurnsSideType.Black, [
+            new CCChariot (this, TurnsSideType.Black, new Vector2I( 4, 0)),
+            new CCHorse   (this, TurnsSideType.Black, new Vector2I( 3, 0)),
+            new CCElephant(this, TurnsSideType.Black, new Vector2I( 2, 0)),
+            new CCAdvisor (this, TurnsSideType.Black, new Vector2I( 1, 0)),
+            new CCGeneral (this, TurnsSideType.Black, new Vector2I( 0, 0)),
+            new CCAdvisor (this, TurnsSideType.Black, new Vector2I(-1, 0)),
+            new CCElephant(this, TurnsSideType.Black, new Vector2I(-2, 0)),
+            new CCHorse   (this, TurnsSideType.Black, new Vector2I(-3, 0)),
+            new CCChariot (this, TurnsSideType.Black, new Vector2I(-4, 0)),
+            new CCCannon  (this, TurnsSideType.Black, new Vector2I( 3, 2)),
+            new CCCannon  (this, TurnsSideType.Black, new Vector2I(-3, 2)),
+            new CCPawn    (this, TurnsSideType.Black, new Vector2I(-4, 3)),
+            new CCPawn    (this, TurnsSideType.Black, new Vector2I(-2, 3)),
+            new CCPawn    (this, TurnsSideType.Black, new Vector2I( 0, 3)),
+            new CCPawn    (this, TurnsSideType.Black, new Vector2I( 2, 3)),
+            new CCPawn    (this, TurnsSideType.Black, new Vector2I( 4, 3)),
+        ]);
 
-        // ArrayList redPart = InitOnePartPieces(TurnsSideType.Red, new[] {
-        //     ("车", 0, -0), ("马", 1, -0), ("象", 2, -0),
-        //     ("士", 3, -0), ("将", 4, -0), ("士", 5, -0),
-        //     ("象", 6, -0), ("马", 7, -0), ("车", 8, -0),
-        //     ("炮", 1, -2), ("炮", 7, -2),
-        //     ("卒", 0, -3), ("卒", 2, -3), ("卒", 4, -3), ("卒", 6, -3), ("卒", 8, -3)
-        //     });
-        ArrayList blackPart = InitOnePartPieces(TurnsSideType.Black, new CCPiece[] {
-            new CCChariot (this, TurnsSideType.Black, new Vector2I( 4, 0)), //  4,0
-            new CCHorse   (this, TurnsSideType.Black, new Vector2I( 3, 0)), //  3,0
-            new CCElephant(this, TurnsSideType.Black, new Vector2I( 2, 0)), //  2,0
-            new CCAdvisor (this, TurnsSideType.Black, new Vector2I( 1, 0)), //  1,0
-            new CCGeneral (this, TurnsSideType.Black, new Vector2I( 0, 0)), //  0,0
-            new CCAdvisor (this, TurnsSideType.Black, new Vector2I(-1, 0)), // -1,0
-            new CCElephant(this, TurnsSideType.Black, new Vector2I(-2, 0)), // -2,0
-            new CCHorse   (this, TurnsSideType.Black, new Vector2I(-3, 0)), // -3,0
-            new CCChariot (this, TurnsSideType.Black, new Vector2I(-4, 0)), // -4,0
-            new CCCannon  (this, TurnsSideType.Black, new Vector2I( 3, 2)), //  3,2
-            new CCCannon  (this, TurnsSideType.Black, new Vector2I(-3, 2)), // -3,2
-            new CCPawn    (this, TurnsSideType.Black, new Vector2I(-4, 3)), // -4,3
-            new CCPawn    (this, TurnsSideType.Black, new Vector2I(-2, 3)), // -2,3
-            new CCPawn    (this, TurnsSideType.Black, new Vector2I( 0, 3)), //  0,3
-            new CCPawn    (this, TurnsSideType.Black, new Vector2I( 2, 3)), // -4,3
-            new CCPawn    (this, TurnsSideType.Black, new Vector2I( 4, 3))  //  4,3
-        });
-
-        ArrayList redPart = InitOnePartPieces(TurnsSideType.Red, new CCPiece[] {
-            new CCChariot (this, TurnsSideType.Red, new Vector2I( 4, 0)), //  4,0
-            new CCHorse   (this, TurnsSideType.Red, new Vector2I( 3, 0)), //  3,0
-            new CCElephant(this, TurnsSideType.Red, new Vector2I( 2, 0)), //  2,0
-            new CCAdvisor (this, TurnsSideType.Red, new Vector2I( 1, 0)), //  1,0
-            new CCGeneral (this, TurnsSideType.Red, new Vector2I( 0, 0)), //  0,0
-            new CCAdvisor (this, TurnsSideType.Red, new Vector2I(-1, 0)), // -1,0
-            new CCElephant(this, TurnsSideType.Red, new Vector2I(-2, 0)), // -2,0
-            new CCHorse   (this, TurnsSideType.Red, new Vector2I(-3, 0)), // -3,0
-            new CCChariot (this, TurnsSideType.Red, new Vector2I(-4, 0)), // -4,0
-            new CCCannon  (this, TurnsSideType.Red, new Vector2I( 3, 2)), //  3,2
-            new CCCannon  (this, TurnsSideType.Red, new Vector2I(-3, 2)), // -3,2
-            new CCPawn    (this, TurnsSideType.Red, new Vector2I(-4, 3)), // -4,3
-            new CCPawn    (this, TurnsSideType.Red, new Vector2I(-2, 3)), // -2,3
-            new CCPawn    (this, TurnsSideType.Red, new Vector2I( 0, 3)), //  0,3
-            new CCPawn    (this, TurnsSideType.Red, new Vector2I( 2, 3)), //  2,3
-            new CCPawn    (this, TurnsSideType.Red, new Vector2I( 4, 3))  //  4,3
-        });
+        ArrayList redPart = InitOnePartPieces(TurnsSideType.Red, [
+            new CCChariot (this, TurnsSideType.Red, new Vector2I( 4, 0)),
+            new CCHorse   (this, TurnsSideType.Red, new Vector2I( 3, 0)),
+            new CCElephant(this, TurnsSideType.Red, new Vector2I( 2, 0)),
+            new CCAdvisor (this, TurnsSideType.Red, new Vector2I( 1, 0)),
+            new CCGeneral (this, TurnsSideType.Red, new Vector2I( 0, 0)),
+            new CCAdvisor (this, TurnsSideType.Red, new Vector2I(-1, 0)),
+            new CCElephant(this, TurnsSideType.Red, new Vector2I(-2, 0)),
+            new CCHorse   (this, TurnsSideType.Red, new Vector2I(-3, 0)),
+            new CCChariot (this, TurnsSideType.Red, new Vector2I(-4, 0)),
+            new CCCannon  (this, TurnsSideType.Red, new Vector2I( 3, 2)),
+            new CCCannon  (this, TurnsSideType.Red, new Vector2I(-3, 2)),
+            new CCPawn    (this, TurnsSideType.Red, new Vector2I(-4, 3)),
+            new CCPawn    (this, TurnsSideType.Red, new Vector2I(-2, 3)),
+            new CCPawn    (this, TurnsSideType.Red, new Vector2I( 0, 3)),
+            new CCPawn    (this, TurnsSideType.Red, new Vector2I( 2, 3)),
+            new CCPawn    (this, TurnsSideType.Red, new Vector2I( 4, 3)),
+        ]);
 
         return (blackPart, redPart);
     }
 
     private ArrayList InitOnePartPieces(TurnsSideType side, CCPiece[] pieces) {
-        ArrayList list = new();
+        ArrayList list = [];
         foreach (var piece in pieces) {
             list.Add(piece);
             InsertPiece(piece, piece.Pos);
diff --git a/Scripts/Src/ChineseChess/CCMain.cs b/Scripts/Src/ChineseChess/CCMain.cs
index c2e5481..a7ac64e 100644
--- a/Scripts/Src/ChineseChess/CCMain.cs
+++ b/Scripts/Src/ChineseChess/CCMain.cs
@@ -1,6 +1,8 @@
 using Vector2 = Vector.Vector2I;
 using System;
 using System.Collections;
+using static IBoard.IBoardOn;
+
 namespace ChineseChess;
 
 public class ChessCore {
@@ -23,17 +25,18 @@ public class ChessCore {
 
     private TurnsSideType sideType = TurnsSideType.Red;
     private readonly TurnsSideType selfSide;
-    public readonly CCBoard board = new();
+    public readonly CCBoard board;
     private readonly Player playerSelf;
     private readonly Player playerOpponent;
     // public EventHandler<IBoard.MoveEventArgs> OnMove;
-    public ChessCore(Mode mode, TurnsSideType selfSide) {
+    public ChessCore(Mode mode, TurnsSideType selfSide, ICCBoardOn? boardOn = null) {
         this.selfSide = selfSide;
+        board = new(boardOn);
 
         playerSelf = new(board, Player.PlayerType.Human);
         playerOpponent = new(board, Player.PlayerType.Human);
 
-        void func(object? _self, IBoard.MoveEventArgs record) {
+        void func(object? _self, MoveEventArgs record) {
             // 防止 Undo 时 Selected Clear 出现 Null Pointer Exception
             playerSelf.SelectedClear();
             playerOpponent.SelectedClear();
diff --git a/Scripts/Src/ChineseChess/CCPiece.cs b/Scripts/Src/ChineseChess/CCPiece.cs
index 4666351..87935e4 100644
--- a/Scripts/Src/ChineseChess/CCPiece.cs
+++ b/Scripts/Src/ChineseChess/CCPiece.cs
@@ -1,6 +1,5 @@
 namespace ChineseChess;
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using Vector;
@@ -20,11 +19,14 @@ public class CCPiece : AbstractPiece {
             string name = "", Vector2I? pos = null) : base(name) {
         this.board = board ?? new();
         TurnsSide = turnsSide;
-        OnPos += (sender, args) => {
-            localPos = Global2Local(Pos);
-        };
         Pos = pos is not null ? Local2Global(pos) : Vector2I.Zero;
-        localPos = Global2Local(Pos);
+    }
+
+    public override Vector2I Pos {
+        get => base.Pos; set {
+            base.Pos = value;
+            localPos = Global2Local(Pos);
+        }
     }
 
     public override bool CanMove(Vector2I to) {
@@ -44,18 +46,18 @@ public class CCPiece : AbstractPiece {
     }
 
     public virtual List<Vector2I> CanMoveAllPosSelf() {
-        return new List<Vector2I>();
+        return [];
     }
 
     public IEnumerable<Vector2I> CanMoveAllPosLocal() {
-        var self = CanMoveAllPosSelf().Select(item => item + localPos);// 转换局部坐标
+        var self = CanMoveAllPosSelf().Select(item => item + localPos);
         var ret = self.Where(item => {
             CCPiece? piece = GetCCPieceLocal(item);
             bool ret = piece is null || piece.TurnsSide != TurnsSide;
             // Console.WriteLine($"{item} can move: {ret}");
             return ret;
-        });  // 过滤无效位置
-        
+        });
+
         // Console.WriteLine("localPos: {0}", localPos);
         // Console.WriteLine("CanMoveAllPosSelf: {0}", string.Join(",", self));
         // Console.WriteLine("CanMoveAllPosLocal: {0}", string.Join(",", ret));
@@ -64,7 +66,7 @@ public class CCPiece : AbstractPiece {
 
     public IEnumerable<Vector2I> CanMoveAllPos() {
         var ret = CanMoveAllPosLocal()
-            .Select(item => Local2Global(item));  // 转换为全局坐标
+            .Select(item => Local2Global(item));
         // Console.WriteLine("CanMoveAllPos: {0}", string.Join(",", ret));
         return ret;
     }
diff --git a/Scripts/Src/ChineseChess/CCPlayer.cs b/Scripts/Src/ChineseChess/CCPlayer.cs
index 2525a2e..e965a4d 100644
--- a/Scripts/Src/ChineseChess/CCPlayer.cs
+++ b/Scripts/Src/ChineseChess/CCPlayer.cs
@@ -3,11 +3,12 @@ using System.Collections;
 using Vector2I = Vector.Vector2I;
 
 namespace ChineseChess;
+using static IBoard.IBoardOn;
 public class Player {
 	private readonly CCBoard board;
 	private readonly SelectedPiece selectedNode;
 	
-	public EventHandler<IBoard.MoveEventArgs>? OnMove;
+	public EventHandler<MoveEventArgs>? OnMove;
 	public bool CanMove { get; set; } = true;
 
 	public enum PlayerType {
@@ -15,8 +16,7 @@ public class Player {
 		AI
 	}
 
-	public Player(CCBoard board, PlayerType type = PlayerType.Human)
-	{
+	public Player(CCBoard board, PlayerType type = PlayerType.Human) {
 		this.board = board;
 		this.selectedNode = new SelectedPiece(board);
 	}
@@ -56,9 +56,9 @@ public class Player {
 		}
 
 		// MUST BE THERE !!! 防止删除节点后在启动回调导致错误
-		OnMove?.Invoke(this, new IBoard.MoveEventArgs
-			{ From = fromPos, To = toPos, Piece = fromChess });;
-
+		OnMove?.Invoke(this, new MoveEventArgs
+			(fromChess, fromPos, toPos));
+	
         if (toChess != null) {
             board.RemovePiece(toPos);
         }
diff --git a/Scripts/Src/IBoard.cs b/Scripts/Src/IBoard.cs
index 2ab69b2..2347f04 100644
--- a/Scripts/Src/IBoard.cs
+++ b/Scripts/Src/IBoard.cs
@@ -1,32 +1,33 @@
 using System;
+using Godot;
 using Vector2I = Vector.Vector2I;
 
+
 public interface IBoard {
+    public interface IBoardOn {
+        void OnInsert(object self, IPiece piece) {}
+        void OnRemove(object self, IPiece piece) {}
+        void OnMove(object self, MoveEventArgs args) {}
+
+        void OnAddRecord(object self, MoveRecord record) {}
+        void OnUndoRecord(object self, MoveRecord record) {}
+        void OnSetPieceInteral(object self, SetPieceEventArgs args) {}
+        record SetPieceEventArgs(IPiece? OldPiece, IPiece? NewPiece, Vector2I Pos);
+        record MoveEventArgs(IPiece? Piece, Vector2I From, Vector2I To);
+    }
+
+    public IBoardOn? On { get; protected set; }
     public int Rows { get; }
     public int Cols { get; }
 
-    public class SetPieceEventArgs : EventArgs {
-        public IPiece? OldPiece { get; set; }
-        public IPiece? NewPiece { get; set; }
-        public Vector2I Pos { get; set; } = new();
-    }
-
-    public class MoveEventArgs : EventArgs {
-        public IPiece? Piece { get; set; }
-        public Vector2I From { get; set; } = new();
-        public Vector2I To { get; set; } = new();
-    }
-
-    event EventHandler<IPiece> OnInsert;
-    event EventHandler<IPiece> OnRemove;
-    event EventHandler<MoveEventArgs> OnMove;
-    event EventHandler<SetPieceEventArgs> OnSetPiece;
-
     bool IsPosOutOfRange(Vector2I pos);
     IPiece? GetPiece(Vector2I pos);
-    IPiece? SetPiece(IPiece piece, Vector2I pos);
+    IPiece? SetPiece(IPiece? piece, Vector2I pos);
     bool InsertPiece(IPiece piece, Vector2I pos);
     bool MovePiece(Vector2I from, Vector2I to);
     IPiece? RemovePiece(Vector2I pos);
-    void Clear();
+    void Clear(bool clearRecords);
+    void AddRecord(IPiece? From, IPiece? To, Vector2I FromPos, Vector2I ToPos);
+    void UndoRecord();
+    record MoveRecord(IPiece? From, IPiece? To, Vector2I FromPos, Vector2I ToPos);
 }
diff --git a/Scripts/Src/IPiece.cs b/Scripts/Src/IPiece.cs
index 9d4725e..059cf03 100644
--- a/Scripts/Src/IPiece.cs
+++ b/Scripts/Src/IPiece.cs
@@ -2,17 +2,21 @@ using System;
 using System.Collections.Generic;
 using Vector2I = Vector.Vector2I;
 
+
 public interface IPiece {
+    public interface IPieceOn {
+        void OnPos(object self, Vector2I oldPos) {}
+        void OnMove(object self, Vector2I oldPos) {}
+        void OnSelected(object self, bool oldIsSelected) {}
+        void OnName(object self, string oldName) {}
+    }
+
+    IPieceOn? On { get; protected set; }
     Vector2I Pos { get; set; }
     string Name { get; set; }
     bool IsSelected { get; set; }
     Dictionary<string, object> Data { get; set; }
 
-    event EventHandler<Vector2I> OnPos;
-    event EventHandler<Vector2I> OnMove;
-    event EventHandler<bool> OnSelected;
-    event EventHandler<string> OnName;
-
     bool CanMove(Vector2I to);
     bool Move(Vector2I pos);
 }
diff --git a/Test/Test.csproj b/Test/Test.csproj
index 7e5d662..f11c34d 100644
--- a/Test/Test.csproj
+++ b/Test/Test.csproj
@@ -21,11 +21,11 @@
     <Using Include="NUnit.Framework" />
   </ItemGroup>
 
-  <!-- <ItemGroup>
-    <ProjectReference Include="..\Chinese_Chess.csproj" />
-  </ItemGroup> -->
   <ItemGroup>
-    <Compile Include="..\Scripts\Src\*.cs" />
+    <ProjectReference Include="..\*.csproj" />
   </ItemGroup>
+  <!-- <ItemGroup>
+    <Compile Include="..\Scripts\Src\*.cs" />
+  </ItemGroup> -->
 
 </Project>
diff --git a/Test/src/TestVector.cs b/Test/src/TestVector.cs
index 3246fa1..148f397 100644
--- a/Test/src/TestVector.cs
+++ b/Test/src/TestVector.cs
@@ -1,21 +1,147 @@
 using Vector;
-namespace Test;
-public class TestsVector
-{
+namespace Test.Vector;
+public class TestsVector2I {
     [SetUp]
-    public void Setup()
-    {
+    public void Setup() {
     }
 
     [Test]
-    public void Test1()
-    {
+    public void TestVector2I_Constructors() {
+        // Arrange & Act
+        var v1 = new Vector2I();
+        var v2 = new Vector2I(1, 2);
+        var v3 = new Vector2I(v2);
+
+        // Assert
+        Assert.Multiple(() => {
+            Assert.That(v1.X, Is.EqualTo(0));
+            Assert.That(v1.Y, Is.EqualTo(0));
+            Assert.That(v2.X, Is.EqualTo(1));
+            Assert.That(v2.Y, Is.EqualTo(2));
+            Assert.That(v3.X, Is.EqualTo(1));
+            Assert.That(v3.Y, Is.EqualTo(2));
+        });
+    }
+
+    [Test]
+    public void TestVector2I_Operators() {
+        // Arrange
+        var v1 = new Vector2I(1, 2);
+        var v2 = new Vector2I(3, 4);
+
+        // Act
+        var v3 = v1 + v2;
+        var v4 = v1 - v2;
+        var v5 = v1 * v2;
+
+        // Assert
+        Assert.Multiple(() => {
+            Assert.That(v3, Is.EqualTo(new Vector2I(4, 6)));
+            Assert.That(v4, Is.EqualTo(new Vector2I(-2, -2)));
+            Assert.That(v5, Is.EqualTo(new Vector2I(3, 8)));
+        });
+    }
+
+    [Test]
+    public void TestVector2I_DotProduct() {
+        // Arrange
+        var v1 = new Vector2I(1, 2);
+        var v2 = new Vector2I(3, 4);
+
+        // Act
+        var dotProduct = v1.Dot(v2);
+
+        // Assert
+        Assert.That(dotProduct, Is.EqualTo(11));
+    }
+
+    [Test]
+    public void TestVector2I_ParameterModification() {
+        // Arrange
+        var v1 = new Vector2I(1, 2);
+        var v2 = new Vector2I(3, 4);
+
+        // Act
+        var v3 = v1 + v2;
+        var v4 = v1 - v2;
+        var v5 = v1 * v2;
+
+        // Assert
+        Assert.Multiple(() => {
+            Assert.That(v1, Is.EqualTo(new Vector2I(1, 2)), "v1 should not be modified");
+            Assert.That(v2, Is.EqualTo(new Vector2I(3, 4)), "v2 should not be modified");
+        });
+    }
+
+    [Test]
+    public void TestVector2I_Equality() {
+        // Arrange
+        var v1 = new Vector2I(1, 2);
+        var v2 = new Vector2I(1, 2);
+        var v3 = new Vector2I(3, 4);
+
+        // Act & Assert
+        Assert.Multiple(() => {
+            Assert.That(v1, Is.EqualTo(v2));
+            Assert.That(v1, Is.Not.EqualTo(v3));
+        });
+    }
+
+    [Test]
+    public void TestVector2I_HashCode() {
+        // Arrange
+        var v1 = new Vector2I(1, 2);
+        var v2 = new Vector2I(1, 2);
+        var v3 = new Vector2I(3, 4);
+
+        // Act & Assert
+        Assert.Multiple(() => {
+            Assert.That(v1.GetHashCode(), Is.EqualTo(v2.GetHashCode()));
+            Assert.That(v1.GetHashCode(), Is.Not.EqualTo(v3.GetHashCode()));
+        });
+    }
+
+    [Test]
+    public void TestVector2I_BoundaryValues() {
+        // Arrange
+        var v1 = new Vector2I(0, 0);
+        var v2 = new Vector2I(-1, -2);
+        var v3 = new Vector2I(int.MaxValue, int.MaxValue);
+        var v4 = new Vector2I(int.MinValue, int.MinValue);
+
+        // Act
+        var v5 = v1 + v2;
+        var v6 = v1 - v2;
+        var v7 = v1 * v2;
+        var v8 = v3 + v4;
+        var v9 = v3 - v4;
+        var v10 = v3 * v4;
+
+        // Assert
+        Assert.Multiple(() => {
+            Assert.That(v5, Is.EqualTo(new Vector2I(-1, -2)));
+            Assert.That(v6, Is.EqualTo(new Vector2I(1, 2)));
+            Assert.That(v7, Is.EqualTo(new Vector2I(0, 0)));
+
+            Assert.That(v8, Is.EqualTo(new Vector2I(-1, -1)));
+            // Assert.That(v9, Is.EqualTo(new Vector2I(2 * int.MaxValue - 1, 2 * int.MaxValue - 1)));
+            // Assert.That(v10, Is.EqualTo(new Vector2I(int.MaxValue * int.MinValue, int.MaxValue * int.MinValue)));
+        });
+    }
+}
+
+public class TestsTrans2DI {
+    [SetUp]
+    public void Setup() {
+    }
+
+    [Test]
+    public void Test1() {
         Assert.Pass();
     }
 
     [Test]
-    public void TestVector2I_Constructors()
-    {
+    public void TestVector2I_Constructors() {
         // Arrange & Act
         var v1 = new Vector2I();
         var v2 = new Vector2I(1, 2);
@@ -31,8 +157,7 @@ public class TestsVector
     }
 
     [Test]
-    public void TestVector2I_Operators()
-    {
+    public void TestVector2I_Operators() {
         // Arrange
         var v1 = new Vector2I(1, 2);
         var v2 = new Vector2I(3, 4);
@@ -49,8 +174,7 @@ public class TestsVector
     }
 
     [Test]
-    public void TestTrans2DI_Constructors()
-    {
+    public void TestTrans2DI_Constructors() {
         // Arrange & Act
         var t1 = new Trans2DI();
         var t2 = new Trans2DI(new Vector2I(1, 0), new Vector2I(0, 1), new Vector2I(0, 0));
@@ -76,8 +200,7 @@ public class TestsVector
     }
 
     [Test]
-    public void TestTrans2DI_Operators()
-    {
+    public void TestTrans2DI_Operators() {
         // Arrange
         var t1 = new Trans2DI(new Vector2I(1, 0), new Vector2I(0, 1), new Vector2I(1, 2));
         var v1 = new Vector2I(3, 4);
@@ -90,4 +213,51 @@ public class TestsVector
         Assert.That(v2, Is.EqualTo(new Vector2I(4, 6)));
         Assert.That(v3, Is.EqualTo(new Vector2I(2, 2)));
     }
+
+    [Test]
+    public void TestTrans2DI_BoundaryValues() {
+        // Arrange
+        var t1 = new Trans2DI(new Vector2I(int.MaxValue, 0), new Vector2I(0, int.MaxValue), new Vector2I(0, 0));
+        var t2 = new Trans2DI(new Vector2I(int.MinValue, 0), new Vector2I(0, int.MinValue), new Vector2I(0, 0));
+        var v1 = new Vector2I(1, 1);
+
+        // Act
+        var v2 = t1 * v1;
+        var v3 = t2 * v1;
+
+        // Assert
+        Assert.That(v2, Is.EqualTo(new Vector2I(int.MaxValue, int.MaxValue)));
+        Assert.That(v3, Is.EqualTo(new Vector2I(int.MinValue, int.MinValue)));
+    }
+
+    [Test]
+    public void TestTrans2DI_SpecialValues() {
+        // Arrange
+        var t1 = new Trans2DI(new Vector2I(0, 0), new Vector2I(0, 0), new Vector2I(0, 0));
+        var t2 = new Trans2DI(new Vector2I(1, 0), new Vector2I(0, 1), new Vector2I(0, 0));
+        var v1 = new Vector2I(1, 1);
+
+        // Act
+        var v2 = t1 * v1;
+        var v3 = t2 * v1;
+
+        // Assert
+        Assert.That(v2, Is.EqualTo(new Vector2I(0, 0)));
+        Assert.That(v3, Is.EqualTo(new Vector2I(1, 1)));
+    }
+
+    [Test]
+    public void TestTrans2DI_Multiplication() {
+        // Arrange
+        var t1 = new Trans2DI(new Vector2I(1, 0), new Vector2I(0, 1), new Vector2I(1, 2));
+        var t2 = new Trans2DI(new Vector2I(2, 0), new Vector2I(0, 2), new Vector2I(3, 4));
+
+        // Act
+        var t3 = t1 * t2;
+
+        // Assert
+        Assert.That(t3.XAxis, Is.EqualTo(new Vector2I(2, 0)));
+        Assert.That(t3.YAxis, Is.EqualTo(new Vector2I(0, 2)));
+        Assert.That(t3.Origin, Is.EqualTo(new Vector2I(5, 8)));
+    }
 }
\ No newline at end of file
diff --git a/project.godot b/project.godot
index 6bd330f..6701b30 100644
--- a/project.godot
+++ b/project.godot
@@ -10,10 +10,11 @@ config_version=5
 
 [application]
 
-config/name="Chinese_Chess"
+config/name="ChessGame"
+config/version="0.0.5"
 run/main_scene="res://Main.tscn"
 config/features=PackedStringArray("4.3", "C#", "Mobile")
-config/icon="res://icon.svg"
+config/icon="res://Asserts/icon.svg"
 
 [autoload]
 
@@ -28,7 +29,12 @@ window/handheld/orientation=1
 
 [dotnet]
 
-project/assembly_name="Chinese_Chess"
+project/assembly_name="ChessGame"
+
+[navigation]
+
+2d/name_localized={}
+2d/version="0.0."
 
 [rendering]