En Passant

En passant (French for “in passing”) is a special pawn capture that lets a pawn take an enemy pawn that has just advanced two squares, as if the enemy pawn had moved only one square.

The capture is possible only on the move immediately after the two-square advance. If the opponent does not take en passant at once, the right disappears permanently.

Conditions required

• The capturing pawn must already stand on its fifth rank (White) or fourth rank (Black).
• The captured pawn must have started on its second rank (White) or seventh rank (Black) and advanced exactly two squares in a single move, landing on a square adjacent to the capturing pawn.
• The capture is executed by moving the capturing pawn diagonally forward to the square the enemy pawn passed over; the enemy pawn is then removed from the board.

How the move is made

Suppose a White pawn stands on e5 and Black plays …d7-d5. White may now capture en passant by playing exd6, removing the pawn from d5 and placing the White pawn on d6. The same rule applies symmetrically for Black.

{"v":1,"type":"board","orientation":"white","fen":"rnbqkbnr/ppp1pppp/8/3pP3/8/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 3","arrows":[{"from":"e5","to":"d6","color":"good"}],"highlights":[{"square":"d5","color":"bad"}],"caption":"White captures en passant with exd6.","alt":"Position after Black has played d7-d5. White pawn on e5 captures the pawn on d5 by moving to d6; the captured pawn is removed from d5."}

Notation

In algebraic notation the move is written exactly like any other pawn capture (for example, exd6). The optional suffix “e.p.” is never required by modern rules.

Purpose of the rule

Without en passant, a pawn could slip past an enemy pawn on an adjacent file simply by advancing two squares, undermining the principle that pawns capture diagonally and cannot be bypassed. The rule restores that balance while preserving the option of a two-square first move.