Castling, En Passant and Stalemate Explained
Castling moves your king two squares towards a rook, and the rook jumps to the square the king crossed. En passant lets a pawn capture an enemy pawn that has just moved two squares to land beside it, as if it had moved only one. Stalemate is when the player to move is not in check but has no legal move: the game is a draw.
What is castling?
Castling is the only move in chess where you move two pieces at once: your king and one of your rooks. It does two useful jobs in one turn, tucking the king away behind its pawns and bringing a rook towards the centre.
How to castle
- Kingside (short) castling: the king moves two squares towards the h-rook (e1 to g1 for White), and the rook jumps over to the square next to it (h1 to f1). Written O-O.
- Queenside (long) castling: the king moves two squares towards the a-rook (e1 to c1), and the rook jumps to d1. Written O-O-O.
Black castles the same way on the eighth row: the king goes to g8 or c8, the rook to f8 or d8. In tournament play, move the king first and then the rook, with one hand.
When you can't castle
You may castle only if all of these are true:
- Your king has never moved this game.
- The rook you're castling with has never moved.
- There are no pieces between the king and that rook.
- Your king is not in check right now.
- The king does not pass through a square attacked by an enemy piece.
- The king does not end up in check.
Some things people often think are banned but aren't: the rook may be under attack, and when castling queenside the rook may pass over an attacked square (b1 or b8), because only the king's path matters. You can also still castle later if you were in check earlier, as long as you got out of it without moving the king.
What is en passant?
En passant is French for "in passing". It exists because of the pawn's two-square first move. Without it, a pawn could sneak past an enemy pawn that would have been able to capture it if it had moved just one square.
Here's the rule. If an enemy pawn moves two squares from its starting square and lands right beside your pawn, your pawn may capture it as if it had moved only one square: you move diagonally onto the square it skipped, and the enemy pawn is removed.
- Only pawns can capture en passant, and only pawns can be captured this way.
- Your pawn must be on its fifth row (row 5 for White, row 4 for Black) for it to be possible.
- You must do it immediately, on the very next move. If you play something else, the chance is gone.
- It's optional, unless it's your only legal move, in which case you have to play it like any other move.
What is stalemate?
Stalemate happens when the player whose turn it is has no legal moves but their king is not in check. The game ends immediately in a draw. Neither side wins, no matter how much material one player has.
This catches out a lot of beginners who are winning easily: they take every enemy piece, then accidentally leave the lone king with nowhere to go. Here's the classic example:
| King in check? | Any legal move? | Result | |
|---|---|---|---|
| Check | Yes | Yes | Game goes on; you must get out of check |
| Checkmate | Yes | No | The attacking side wins |
| Stalemate | No | No | Draw |
When you're far ahead, before every move ask: "After this, does my opponent have a legal move?" If the answer is no and their king isn't in check, find a different move.
Other ways a chess game can be drawn
Stalemate is one of several draws. The others you'll meet:
- Threefold repetition: the same position occurs three times with the same player to move.
- The 50-move rule: 50 moves by each player without any capture or pawn move.
- Not enough material: neither side can possibly checkmate, for example king against king, or king and bishop against king.
- Agreement: both players agree to a draw.
GameLake's chess plays every one of these rules, including castling, en passant and pawn promotion, so you can practise them against Hop or with a friend. New to the pieces themselves? Start with how chess pieces move.
Frequently asked questions
Can you castle out of check?
No. You can't castle while your king is in check, and the king can't pass through or land on an attacked square. You may castle later if you got out of check without moving the king.
Can you castle if the rook is under attack?
Yes. Only the king's starting square, the square it crosses and the square it lands on must be safe.
Is en passant mandatory?
No, it's optional, and it's only available on the move immediately after the enemy pawn's two-square advance. It only becomes compulsory if it happens to be your only legal move.
Is stalemate a win or a draw?
A draw. If the player to move has no legal moves and is not in check, the game ends in a draw, even if the other side has far more pieces.
What is the difference between checkmate and stalemate?
In checkmate the king is in check and can't escape, so the attacker wins. In stalemate the king is not in check but the player has no legal move, so the game is a draw.