Castling
"A special move involving the king and a rook, used to improve king safety and activate the rook."
Interactive Demonstration
Visualizing the Concept
Use the interactive board to explore this position. Understanding Castling is much easier when you can visualize the pieces in action.
rnbqk2r/pppp1ppp/5n2/2b1p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4In-Depth Explanation
Castling is the only move in chess where two pieces are moved at once. To castle, the King moves two squares toward a Rook, and that Rook hops over the King to land next to it. It can only be done if neither piece has moved before, there are no pieces between them, and the King is not in check, does not pass through check, and does not land in check.
Recommended Tools
Frequently Asked Questions
No. You cannot castle if your king is currently in check. You must first resolve the check with another move.
No. The king may not move through a square that is attacked, and it may not end its castling move on a square that is attacked.
Kingside castling (O-O) uses the h-file rook and places the king on the g-file. Queenside castling (O-O-O) uses the a-file rook and places the king on the c-file. Queenside is slightly slower and puts the king closer to the open queenside.
In Chess960 (Fischer Random) castling, the king and rook end on the same squares as in standard chess (g/f for kingside, c/d for queenside) but may start on different files. See our Chess960 Castling Helper for a step-by-step check.
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