Castling Rules in Chess: Kingside, Queenside and When You Can't
Nov 11, 2026 · The Editors
Castling rules in chess: how to castle kingside and queenside, the conditions that must be met, castling out of or through check, notation, and castling in Chess960.
Castling is the only move in chess where two pieces move at once. The king moves two squares towards a rook, and that rook jumps to the square the king passed over. It tucks the king into safety and brings the rook towards the centre. You may castle once per game, kingside or queenside, if the conditions below are met.
How to castle
| Kingside (short) | Queenside (long) | |
|---|---|---|
| King (White) | e1 → g1 | e1 → c1 |
| Rook (White) | h1 → f1 | a1 → d1 |
| King (Black) | e8 → g8 | e8 → c8 |
| Rook (Black) | h8 → f8 | a8 → d8 |
| Notation | O-O | O-O-O |
In both directions the king moves exactly two squares.
Castling rules: when you can castle
All of these must be true:
- The king has not moved at any point in the game.
- That rook has not moved. (If only the other rook has moved, you can still castle on this side.)
- No pieces stand between the king and the rook.
- The king is not in check.
- The king does not pass through a square attacked by an enemy piece.
- The king does not land on an attacked square (no move may put your own king in check).
Castling and check: what is allowed
- You cannot castle out of check. Deal with the check first; you may castle on a later move, as long as the king itself did not move.
- You cannot castle through check. On the kingside, f1 (or f8) must not be attacked; on the queenside, d1 (or d8).
- The rook may be attacked. Castling is allowed even if the rook is under attack.
- On the queenside, b1 (or b8) may be attacked. The rook passes over that square, but the king does not, so it does not matter.
- Having been in check earlier does not stop you castling later, if the king never moved.
How to castle on the board
Under the official rules, castling is a king move: touch the king first, move it two squares, then move the rook — with one hand. If you touch the rook first, an arbiter could rule that you must make a rook move instead. In a casual game nobody minds, but the habit is worth having.
Castling queenside vs kingside
Kingside castling is quicker (only the knight and bishop need to move out of the way) and is the more common choice. Queenside castling takes one more move to prepare and leaves the a-pawn less protected, but puts the rook straight on the d-file. Many chess openings for beginners aim to castle kingside within the first ten moves.
Castling in Chess960
In Chess960 (Fischer random chess), the back-row pieces start in shuffled positions. Castling still ends with the king and rook on the same squares as in normal chess — king on g1 and rook on f1 for kingside, king on c1 and rook on d1 for queenside — and the same conditions apply.
Castling is one of chess's three special moves, with en passant and promotion. The full rules are in chess rules for beginners.
Frequently asked questions
Can you castle out of check?
No. You must get out of check first. You can castle on a later move if the king has not moved.
Can you castle if the rook is attacked?
Yes. Only the king's squares matter: the king must not be in check, pass through an attacked square or land on one.
Can you castle after your king has been in check?
Yes, as long as the king did not move to escape the check.
How do you write castling in chess notation?
Kingside castling is written O-O and queenside castling O-O-O.
