diff --git a/Qwirkle/QwirkleClassLibrary/Games/Game.cs b/Qwirkle/QwirkleClassLibrary/Games/Game.cs
index 739efb5..d5e8d19 100644
--- a/Qwirkle/QwirkleClassLibrary/Games/Game.cs
+++ b/Qwirkle/QwirkleClassLibrary/Games/Game.cs
@@ -7,7 +7,6 @@ using QwirkleClassLibrary.Events;
 using QwirkleClassLibrary.Players;
 using System.ComponentModel;
 using System.Runtime.CompilerServices;
-using static System.Formats.Asn1.AsnWriter;
 
 namespace QwirkleClassLibrary.Games
 {
@@ -559,7 +558,7 @@ namespace QwirkleClassLibrary.Games
         /// <param name="nbTiles"></param>
         /// <param name="checkdoubles"></param>
         /// <returns></returns>
-        public static bool CheckTileInCompletedLines(Tile? t1, ref int nbTiles, ref List<Tile> checkdoubles)
+        public bool CheckTileInCompletedLines(Tile? t1, ref int nbTiles, ref List<Tile> checkdoubles)
         {
             if (t1! != null!)
             {
@@ -587,7 +586,7 @@ namespace QwirkleClassLibrary.Games
         /// <param name="b"></param>
         /// <param name="checkdoubles"></param>
         /// <returns></returns>
-        public static bool CheckWrongCompletedLines(int x, int y, int dx, int dy, Board b, ref List<Tile> checkdoubles)
+        public bool CheckWrongCompletedLines(int x, int y, int dx, int dy, Board b, ref List<Tile> checkdoubles)
         {
             int nbTiles = 1;
             
diff --git a/Qwirkle/QwirkleClassLibrary/Tiles/Tile.cs b/Qwirkle/QwirkleClassLibrary/Tiles/Tile.cs
index 45bd8c6..4c72ccf 100644
--- a/Qwirkle/QwirkleClassLibrary/Tiles/Tile.cs
+++ b/Qwirkle/QwirkleClassLibrary/Tiles/Tile.cs
@@ -62,7 +62,7 @@ namespace QwirkleClassLibrary.Tiles
         {
             if (obj == null)
             {
-                throw new NullReferenceException("The object is null.");
+                return 1;
             }
             
             var otherTile = obj as Tile;
diff --git a/Qwirkle/TestBase/TestGame.cs b/Qwirkle/TestBase/TestGame.cs
index 5dd518e..6c5637a 100644
--- a/Qwirkle/TestBase/TestGame.cs
+++ b/Qwirkle/TestBase/TestGame.cs
@@ -384,7 +384,7 @@ public class TestGame
     [Fact]
     public void Test_CheckTileInCompletedLines()
     {
-        
+        var game = new Game();
         int nbTiles = 0;
         var checkdoubles = new List<Tile>()
         {
@@ -395,30 +395,26 @@ public class TestGame
         
         var t1 = new Tile(Shape.Club, Color.Green);
         
-        Assert.False(Game.CheckTileInCompletedLines(t1, ref nbTiles, ref checkdoubles));
+        Assert.False(game.CheckTileInCompletedLines(t1, ref nbTiles, ref checkdoubles));
     }
 
     [Fact]
     public void Test_CheckWrongCompletedLines()
     {
-        // Arrange
         var game = new Game();
         var board = new Board(17, 14);
         var checkDoubles = new List<Tile>();
         int x = 4, y = 1, dx = 1, dy = 0;
 
-        // Add tiles to the board
         board.AddTileInCell(1, 1, new Tile(Shape.Club, Color.Red));
         board.AddTileInCell(2, 1, new Tile(Shape.Square, Color.Red));
         board.AddTileInCell(3, 1, new Tile(Shape.Star, Color.Red));
         board.AddTileInCell(5, 1, new Tile(Shape.Round, Color.Red));
         board.AddTileInCell(6, 1, new Tile(Shape.Shuriken, Color.Red));
         board.AddTileInCell(7, 1, new Tile(Shape.Rhombus, Color.Red));
+        
+        bool result = game.CheckWrongCompletedLines(x, y, dx, dy, board, ref checkDoubles);
 
-        // Act
-        bool result = Game.CheckWrongCompletedLines(x, y, dx, dy, board, ref checkDoubles);
-
-        // Assert
         Assert.False(result);
     }