Castling is a very special chess move. It is the only move in which more than one piece, a King and a Rook, is moved. Castling is only allowed if both the King as well as the castling Rook have not been moved before. As we will see at the end of this lesson there are even more restrictions, but first we explain how to castle.

To castle, move the King two squares toward the Rook, and then move the Rook to the square immediately on the other side of the King.

In the position of the diagram below the white King can castle on either side of the board.



Castling is only allowed when:

• The King and castling Rook have never moved during this game


• The King is not in check at the starting square


• The King is not in check at the destination square


• The King is not in check on the squares is passing through


• All the squares between the Rook and the King are vacant

Please note that in the diagram above Black is not allowed to castle on the King-side. (Look at the white Bishop on c4.)
King-side castling is also called short castling. Queen-side castling is called long castling.

The chess lessons continue with 'the end of the game'.