The lines on the board, separating the corner parts from the middle plus- shaped part are called deflection lines . Also, in general, there are restrictions when a piece can take a piece of the opponent. Additionally, when a king is on one of the four squares in the middle of the board, it may be moved in one move to any empty square on the board with the exception of those squares that contain a piece in the opening setup. Kings can only take when moving over a deflection line. A rook moves as a usual rook when in a corner of the board, and as a usual bishop in the middle of the board.
Rooks can only take in moves where they move over a deflection line.
It is not totally clear whether a bishop may pass more than one deflection line in one turn, but I would assume that such moves indeed are possible. Bishops only take in moves where they pass the deflection line, but not when they move only one square in rookwise fashion. Pawns move diagonally towards the middle of the board until they are in the middle part or in the corners of the opponents side of the board. It is allowed to move two squares if the deflection line isn't passed with the first move of the pawn. So, for instance, the white pawn on a4 can move only to b5, but the white pawn on c3 can move to d4 or to e5.