When Can You Castle in Chess? Castling, En Passant, Promotion
Chess has three special moves that start more arguments at the kitchen table than everything else combined: castling, en passant, and promotion. They are not house rules or tournament trivia. They are in the official rules, and the official rules are short enough to settle most disputes in a minute.
Everything below comes from the FIDE Laws of Chess, the rules of the International Chess Federation, in the version that took effect on 1 January 2023, which is still the current Laws listed in the FIDE Handbook as of October 2026. FIDE says the English text is the authentic version. Article numbers are given so you can look them up yourself. If you have an older printout, the 2018 to 2022 version of the Laws says the same things about castling, en passant, and promotion, though a few article numbers differ.
1. The goal, for the record
FIDE's Article 1.4 states the objective: place the opponent's king "under attack" so that the opponent has no legal move. That is checkmate. White always moves first (Article 1.2), and the board is set so the near-right corner square for each player is light (Article 2.1).
2. Castling: how it works
Article 3.8.2 defines castling as a move of the king and one rook along the back rank, "counting as a single move of the king." It is done in a fixed order:
- The king moves two squares toward the rook.
- The rook jumps to the square the king just crossed.
You can castle on either side: kingside, with the nearer rook, or queenside, with the farther one.
3. When castling is not allowed
FIDE splits the restrictions into two kinds.
You lose the right forever (Article 3.8.2.1) if:
- the king has already moved, or
- the rook you want to castle with has already moved.
Moving the king out and back again does not restore the right. Neither does moving a rook away and back.
You are blocked for now (Article 3.8.2.2) if:
- the king's current square, the square it crosses, or the square it lands on is attacked by an opposing piece, or
- any piece stands between the king and the rook.
Those temporary blocks answer the classic questions:
| Question | Answer under FIDE rules |
|---|---|
| Can you castle out of check? | No. The king's own square is attacked. |
| Can you castle through check? | No. The square the king crosses is attacked. |
| Can you castle into check? | No. The landing square is attacked. |
| Can you castle if your rook is attacked? | Yes. Only the king's three squares matter. |
| Can you castle queenside if the square next to the rook is attacked? | Yes, as long as it is empty. The king never crosses it. |
The last two surprise many players. On the queenside the rook passes over one extra square, but the attack rule only covers the squares the king stands on, crosses, and lands on.
4. Touching the king and rook
FIDE's touch-move rules (Article 4) cover castling too. If you touch your king and then a rook, you must castle on that side if it is legal (Article 4.4.1). If you deliberately touch the rook first and then the king, you may not castle on that side on that move (Article 4.4.2). Article 4.1 also says each move must be played with one hand. The safe habit: pick up the king first, move it two squares, then move the rook.
5. En passant: the pawn capture people forget
A pawn on its first move may advance one or two squares (Article 3.7.2). En passant exists so that the two-square jump cannot be used to slip past an enemy pawn.
Article 3.7.3.1 says that if your pawn stands on the same rank as an enemy pawn and on the next file over, and that enemy pawn has just moved two squares from its starting square, you may capture it as though it had moved only one square. Your pawn moves diagonally into the square the enemy pawn skipped, and the enemy pawn is removed.
The timing rule is strict. Article 3.7.3.2 says the capture is only legal on the very next move. If you do anything else, the chance is gone for that pawn.
A quick check before claiming en passant:
- Did the enemy pawn just move two squares, on the last move?
- Is your pawn right beside it, on the same rank?
- Is this your very next move?
All three must be yes.
6. Promotion: you are not limited to captured pieces
When a pawn reaches the far rank, Article 3.7.3.3 says it must be exchanged, as part of the same move, for a queen, rook, bishop, or knight of the same color. Two details settle common arguments:
- You can choose any of the four, not only a queen. Picking a knight or rook is legal and sometimes better.
- Your choice is not limited to captured pieces (Article 3.7.3.4). Having two queens is perfectly legal. Article 6.11.2 even lets a tournament player pause the clock to ask the arbiter for a piece that is not available.
The new piece works immediately (Article 3.7.3.5), so a promotion can give check on the spot.
7. Stalemate is a draw, not a win
Article 5.2.1 says the game is drawn when the player to move has no legal move and their king is not in check. That is stalemate. Many casual players count it as a win for the side with more material, but under FIDE's rules it is a draw, and it ends the game immediately.
8. Key takeaways
- Castling moves the king two squares toward a rook, then the rook hops over; it counts as one king move.
- You can never castle after moving that king or that rook, and you cannot castle out of, through, or into check.
- A rook being attacked does not stop castling; only the king's three squares matter.
- En passant is only allowed on the move right after the enemy pawn's two-square advance.
- A promoting pawn can become a queen, rook, bishop, or knight, even if none has been captured, and stalemate is a draw.