One other special rule is called castling. This move allows you to do two important things all in one move: get your king to safety (hopefully), and get your rook out of the corner and into the game. On a player’s turn he may move his king two squares over to one side and then move the rook from that side’s corner to right next to the king on the opposite side. (See the example below.) However, in order to castle, the following conditions must be met:
it must be that king’s very first move
it must be that rook’s very first move
there cannot be any pieces between the king and rook to move
the king may not be in check or pass through check