Castling

Castling moves the king two squares toward a rook, and that rook jumps to the square the king crossed. It is the only move that moves two pieces.

Kingside castling puts the king on g1 for White or g8 for Black, and the rook on f1 or f8. Queenside castling puts the king on c1 or c8, and the rook on d1 or d8.

You can castle only if the king and that rook have not moved, the squares between them are empty, the king is not in check, and the king does not pass through or land on a square that is attacked.

A rook may be attacked and you may still castle, as long as the king does not pass through check. You also cannot castle out of check. You may castle into a pin of some other piece. You may not castle if the king crosses an attacked square.

On the board

8
7
6
5
4
3
2
a1
b
c
d
e
f
g
h

White to move. The king and the kingside rook have not moved, and the squares between them are empty. Castle kingside.

Common mistakes

  • Castling out of check. A check has to be answered by a king move, a block, or a capture. Castling is not one of those answers.
  • Castling after the king has already moved, even if it moved back.
  • Castling through a square the enemy attacks.

Check yourself

How far does the king move when castling?
Can you castle out of check?
Can you castle if the rook has moved and then returned to its square?

Practice castling tactic puzzles