Britannica
Sources used in this answer
When may a player castle in chess?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
chess
Position of chess pieces at the beginning of a game. The pieces are placed on the two ranks closest to the player. In the closest rank, pieces are arranged from left to right: rook, knight, bishop, queen, king, bishop, knight, and rook. In front of that rank, each square has a pawn.
In chess, castling is a special compound move involving the king and a rook. A player may castle only if the following conditions are met:
- First Move: Neither the king nor the rook involved has moved previously in the game.1
- Clear Path: All squares between the king and the rook must be unoccupied.1
- Safety: The king cannot be in check, nor can it pass through or land on a square that is under attack by an enemy piece.1
- Frequency: Each player is permitted to castle only once during a game.1
When castling, the king moves two squares toward the rook, and the rook is placed on the square the king crossed.1