     public private(set) var whiteKingHasMoved: Bool = false
 
     /// The left white rook has moved from A1.
-    public private(set) var leftWhiteRookHasMoved: Bool = false
+    public private(set) var whiteLeftRookHasMoved: Bool = false
 
     /// The right white rook has moved from H1.
-    public private(set) var rightWhiteRookHasMoved: Bool = false
+    public private(set) var whiteRightRookHasMoved: Bool = false
 
     /// The black king has moved from E8.
     public private(set) var blackKingHasMoved: Bool = false
 
     /// The left black rook has moved from A8.
-    public private(set) var leftBlackRookHasMoved: Bool = false
+    public private(set) var blackLeftRookHasMoved: Bool = false
 
     /// The right black rook has moved from H8.
-    public private(set) var rightBlackRookHasMoved: Bool = false
+    public private(set) var blackRightRookHasMoved: Bool = false
 
     /// The game's mode.
     public var mode: Mode

                // Check if the rook for the appropriate color has moved
                switch move.end {
                case (.C, .One):
                    guard !leftWhiteRookHasMoved else {
                        return .Error(.RookMoved(.White, .Left))
                    }
                case (.G, .One):
                    guard !rightWhiteRookHasMoved else {
                        return .Error(.RookMoved(.White, .Right))
                    }
                case (.C, .Eight):
                    guard !leftBlackRookHasMoved else {
                        return .Error(.RookMoved(.Black, .Left))
                    }
                case (.G, .Eight):
                    guard !rightBlackRookHasMoved else {
                        return .Error(.RookMoved(.Black, .Right))
                    }
                default:

        case .Rook:
            switch move.start {
            case (.A, .One):
                whiteLeftRookHasMoved = true
            case (.H, .One):
                whiteRightRookHasMoved = true
            case (.A, .Eight):
                blackLeftRookHasMoved = true
            case (.H, .Eight):
                blackRightRookHasMoved = true
            default:
                break
            }
