En passant is a special pawn capture available immediately after an opposing pawn advances two squares from its starting square and lands beside your pawn on its fifth rank. Your pawn captures diagonally onto the square the opposing pawn passed over, and the opposing pawn is removed from its landing square.
The French phrase means “in passing.” Unlike an ordinary capture, the captured piece is not standing on the destination square. That unusual detail is why the board can look surprising when you first see the move.
Check the conditions in order
An en passant capture requires all of these conditions:
- Your pawn is on its fifth rank: rank five for White or rank four for Black.
- An opposing pawn has just advanced two squares from its starting square.
- That pawn lands on an adjacent file, beside your pawn.
- You capture it on your very next move.
- The capture does not leave your own king in check.
The opportunity expires if you play something else. A pawn that moved only one square does not create an en passant opportunity, even if it finishes beside your pawn.
Article 3.7.3 of the FIDE Laws of Chess describes the capture and its immediate timing.
Replay a legal example for White
This short study line creates the opportunity and uses it:
Start
White's pawn reaches e5. Black then advances the d-pawn from d7 to d5, passing over d6. White plays exd6: the pawn moves from e5 to d6, while Black's pawn is removed from d5.
There was no piece on d6 before the capture. Afterward, d5 is empty and White's pawn is on d6. Replay the line on the analysis board and watch both affected squares.
Understand the same rule for Black
Black captures toward smaller rank numbers. If Black has a pawn on e4 and White has just advanced d2–d4 beside it, Black may be able to play exd3 en passant. Black's pawn goes to d3 and White's pawn disappears from d4.
The rule is symmetrical even though the square numbers run in opposite directions. “Fifth rank” is counted from the capturing player's own side; it does not always mean the board's numbered fifth row.
Remember that king safety still applies
En passant is a choice, not an obligation. It also cannot be used to expose your king to an attack. Removing two pawns from a rank can open a rook or queen's line, so a capture that looks correct from pawn movement alone may still be illegal.
When a tool rejects the move, check the previous move and the full position. Do not assume every pair of adjacent pawns can capture each other en passant.
Read the notation and position information
The move usually appears as an ordinary pawn capture, such as exd6. Its notation does not need a different piece letter. The move history establishes why the capture is available.
A FEN includes an en passant target field, but an indicated target square does not by itself prove that a legal capture exists. There must also be a suitable capturing pawn and a move that preserves king safety. See FEN vs PGN for the difference between a position record and a full game.
Practice the example before trying to recognize it in a fast game. The computer opponent enforces the rule when the position allows it; the basic chess rules explain the other special moves.