Castling is a special and important move in chess. It enhances your king’s safety and opens your rook simultaneously, transforming an open, central king into a safe monarch beyond the protection of a pawn wall.
How to castle
Castling is the one and only chess move where you get to move two pieces at once. To perform the move, you move your king two squares toward one of your rooks, then move the rook to the square your king just vacated. The move can be made on either side of the board:
Kingside (short) castling (0-0): The king moves two squares to the right, from e1 to g1 (e8 to g8 for Black). The h1 (h8) rook jumps over the king to f1 (f8). In the diagram below, white has castled kingside.
Queenside (long) castling (0-0-0): The king moves two squares to the left, from e1 to c1 (or e8 to c8 for Black). The rook on a1 (or a8) then jumps over the king to d1 (or d8). In the diagram below, black has castled queen-side.
Basic rules for castling
A player must meet all of the following conditions to castle:
- No previous movement: The king and rook with which you wish to castle must have moved neither at all during the game.
- No pieces in between: The squares between the king and your chosen rook must be clear.
- No check: Your king must not be in check.
- Safe passage: The king must not move through or land on a square that is under attack from an opponent’s piece.
The stratigic importance of castling
Castling is a crucial tactical as well as strategic advantage that is the reason why most professional games feature castling. Starters are usually recommended to castle earlier in the game, typically within the initial ten moves, to move the king to a secure position.
Castling on opposite sides, or “opposite-side castling,” is likely to produce an aggressive and dynamic game since the players will find themselves driven to use their pawns to attack the opposing king. In such a situation, the attacking player will most likely be able to win the game.