The king is moved 2 squares towards the rook and then the rook is brought around the king to stand beside it.
The squares between the king and the rook must be empty on the side the player wishes to castle on. In picture 1 these squares are empty on both sides so he may castle with either rook.
In picture 2 he has decided to castle on the King's side so he will move his castle to the right as shown by the blue line.
In picture 3 he has done this and his king stands next to his rook. He will now move his rook around the king as shown by the blue lines as shown in picture 4
Picture 3 Picture 4
In picture 5 the move has been completed and the rook stands alongside the king.
Picture 6 takes us back to the start. This time the player has decided to castle on the queen's side so he will move his king 2 squares to the left as shown by the blue line.
Picture 5 Picture 6
Picture 7 shows the position after the king has moved. The rook is then brought around the king to stand beside it as shown by the blue arrow.
Picture 8 shows the completed move.
Picture 7 Picture 8
Although 2 pieces are moved during castelling, it counts as 1 move. The rules say that the king should move first and then the rook. Players do not insist on this in friendly games of chess but it can be enforced in a chess competition. It is best to start doing it the correct way. If you are playing a computer you will probably have to move your king two squares towards the rook and then the computer will carry out the rook's move for you automatically. This will not work if you move the rook first.
When you are not allowed to castle
1.You are not allowed to castle if you have moved your king. This still applies if you have moved the king back to its starting square.
2.If you have moved a rook, you are not allowed to castle with that rook.
3.You are not allowed to castle out of check.
If you can get out of check without moving your king you can castle later in the game.
In diagram 9 the white king is in check from the black rook so he is not allowed to castle to get out of check.
4.You are not allowed to castle into check. In diagram 10 white cannot castle on the king's side because his king would be in check from the knight.
Picture 9 Picture 10
5.You are not allowed to castle through check. In diagram 11, white is not allowed to castle on the king's side because the king would need to pass over a square where it would be in check from the black bishop.
Picture 11 Picture 12
The idea of castelling is to move the king away from the centre where it is in greater danger. When castelling takes place during a game the king may have a line of pawns in front of it to protect it. you can see this in diagram 12 where white has castelled on the king's side and black has castelled on the queen's side.
Writing the castelling move
Castelling on the King's side is written as O-O Castelling on the Queen's side is written as O-O-O
If you have followed the topics through in order you now have only one more rule to learn. Click "en passant" on the black bar below.
