diff --git a/Connect4/connect4_lib/Sources/connect4_lib/BasicDefaultsNoDiag.swift b/Connect4/connect4_lib/Sources/connect4_lib/BasicDefaultsNoDiag.swift
new file mode 100644
index 0000000..5060920
--- /dev/null
+++ b/Connect4/connect4_lib/Sources/connect4_lib/BasicDefaultsNoDiag.swift
@@ -0,0 +1,46 @@
+import Foundation
+
+public struct BasicDefaultsNoDiag : IRules {
+    var minNbRows: Int
+    
+    var maxNbRows: Int
+    
+    var minNbCols: Int
+    
+    var maxNbCols: Int
+    
+    var nbChipsToAlign: Int
+    
+    func isGameOver(byPlayer playerId: Int, ontGrid grid: [[Int?]]) -> (isOver: Bool, hasWinner: Bool, victoryTiles: [(Int?, Int?)]) {
+        
+        var tiles : [(Int?, Int?)] = Array(repeating: (nil, nil), count: nbChipsToAlign)
+
+        
+        
+        /*
+         game over?
+            winner exists?
+                return (true, true, tiles)
+            else
+                return (true, false, tiles) (all tiles at nil)
+        else
+            return (false, false, tiles) (all tiles at nil)
+         */
+        
+        return (isOver: false, hasWinner: false, victoryTiles: tiles);
+    }
+    
+    init?(withMinNbRows minNbRows: Int = 0,
+          withMaxNbRows maxNbRows: Int = 15,
+          withMaxNbCols minNbCols: Int = 0,
+          withMaxNbCols maxNbCols: Int = 15,
+          withNbChipsToAlign nbChipsToAlign: Int = 4) {
+        self.minNbRows = minNbRows
+        self.maxNbRows = maxNbRows
+        self.minNbCols = minNbCols
+        self.maxNbCols = maxNbCols
+        self.nbChipsToAlign = nbChipsToAlign
+    }
+    
+    
+}
diff --git a/Connect4/connect4_lib/Sources/connect4_lib/Board.swift b/Connect4/connect4_lib/Sources/connect4_lib/Board.swift
index 717ec9c..8f06f7b 100644
--- a/Connect4/connect4_lib/Sources/connect4_lib/Board.swift
+++ b/Connect4/connect4_lib/Sources/connect4_lib/Board.swift
@@ -1,5 +1,6 @@
 import Foundation
 
+//TODO implement Equatable?
 public struct Board : CustomStringConvertible {
     
     public let nbRows: Int
diff --git a/Connect4/connect4_lib/Sources/connect4_lib/IRules.swift b/Connect4/connect4_lib/Sources/connect4_lib/IRules.swift
new file mode 100644
index 0000000..4661aa1
--- /dev/null
+++ b/Connect4/connect4_lib/Sources/connect4_lib/IRules.swift
@@ -0,0 +1,10 @@
+import Foundation
+
+protocol IRules {
+    var minNbRows: Int { get }
+    var maxNbRows: Int { get }
+    var minNbCols: Int { get }
+    var maxNbCols: Int { get }
+    var nbChipsToAlign: Int { get }
+    func isGameOver(byPlayer playerId: Int, ontGrid grid: [[Int?]]) -> (isOver: Bool, hasWinner: Bool, victoryTiles: [(Int?, Int?)])
+}