How to Castle in Chess

If not ten out of ten times, at least nine out of ten times, if you’re just starting out, castle every single game. The biggest reason beginners lose in record time is that they don’t secure their king’s safety. Castling is the best way to avoid early accidents.

Black has just castled queenside, and white is ready to do so on either side. Photo: Vera Kudryashova

The simultaneous move of king and rook is, on average, the best move in chess. It is one of the Royal Game’s three special rules (the others are pawn promotion and en passant).

Now let’s cover everything you ever wanted to know about castling, but didn’t know were important to ask!

Why is Castling a Big Deal?

In the starting position:

The rooks are stuck firmly in the corners and are usually the last units to enter the game. When we remember rooks are the second-most powerful pieces in the game (after the queen), it becomes clear that getting your rooks into play first can provide a big, often decisive advantage.

At the same time, castling also allows the king to flee the often-dangerous center for the calmer side of the board, and get out of the way! Still, the bigger reason for castling is getting the rooks into play, in my view.

The Mechanics of Creating a Castle

  • Only with castling is a player is allowed to move two pieces on the same turn — the king and one rook.
  • The king moves exactly two squares towards one of his rooks, and the rook lands on the square between the king’s starting and ending squares.

Before:

After:

Correct Procedure

All chess moves are performed with one hand only, including capturing and castling. Use the same hand to move both pieces (and press the clock, if using one).

Castling is defined as a king move. Start by picking up only the king and move him two squares towards his rook. Then put down the king. Next, pick up the rook and move it to the square between the king’s starting and ending squares.

Do not pick up the rook first, and do not pick up both pieces at the same time!

Restrictions on Castling

  • To castle, all squares between the king and rook must be empty.
  • Castling is not allowed if the king is attacked (“in check”).
  • Castling is also not allowed if the king crosses or lands on a square that is attacked.
  • If the king has moved at all, castling is not allowed for the entire game.
  • If one of the rooks has moved, castling is not allowed with that rook for the entire game.
  • Castling is allowed if the rook is attacked.

Casual players can stop here. If you play in official events, read on…

Tournament Stuff

  • Castling is not allowed if a player touches their rook first. Only the rook can then be moved!
  • Notation. A white king castling towards his rook on h1 is kingside castling, written 0-0. A black king castling towards his rook on a8 is queenside castling, written 0-0-0.
  • Bonus Round: Repetition Claims! To claim a draw by repetition (the same position has occurred, or is about to occur, for the third time), the same moves and captures must be possible in all three positions. That includes castling and en passant.

Feel free to post your questions or thoughts!

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