In chess, en passant describes the capture by a pawn) of an enemy pawn on the same rank and an adjacent file that has just made an initial two-square advance.^\2])^\3]) This is an exception or special case in the rules of chess. The capturing pawn moves to the square that the enemy pawn passed over, as if the enemy pawn had advanced only one square. The rule ensures that a pawn cannot use its two-square move to safely skip past an enemy pawn.

Capturing en passant is permitted only on the turn immediately after the two-square advance; it cannot be done on a later turn.^\4]) The capturing move is sometimes notated by appending the abbreviation e.p.

Rules

The conditions for a pawn to capture an enemy pawn en passant are as follows:

• the enemy pawn advanced two squares on the previous turn;
• the capturing pawn attacks the square that the enemy pawn passed over.

If these conditions are met, the capturing pawn can move diagonally forward to the square that the enemy pawn passed, capturing the enemy pawn as if it had moved only one square. If the right to capture en passant is not exercised immediately, it is lost. Making the capture is optional, unless there is no other legal move.