En PassantEdit

En passant is a special capture in chess that highlights the game's subtle pawn play. The rule exists to prevent a pawn from bypassing the opportunity to be captured when the opponent pushes two squares from its starting position. If a pawn advances two squares and finishes adjacent to an opposing pawn, that opponent may capture the moving pawn as if it had advanced only one square. The capture must be executed on the immediately following move; if the player does not take the opportunity then the right to do so is lost. The term is French for “in passing,” reflecting the way the capture happens as the moving pawn passes by the capturing pawn.

In practice, en passant is a routine, yet sometimes decisive, weapon in pawn play. It affects open games and can influence the structure of the middlegame and endgame. The rule is part of the standard set of chess rules and appears in chess instruction and in discussions of pawn dynamics. An example is often cited to illustrate the mechanism: if a white pawn sits on e5 and black plays d7–d5, white may respond with exd6 e.p., capturing as if the black pawn had stopped on d6. The captured pawn is removed from the board as part of the en passant capture, and the capturing pawn ends on the square the opponent passed over.

Etymology and rule

Etymology

The name en passant comes from the French language term meaning “in passing.” This naming points to the momentary nature of the capture, which only occurs when the opponent’s pawn passes adjacent to the capturing pawn during its double-step. The standard English usage mirrors the original French terminology, and the phrase is commonly written as en passant in both instructional texts and algebraic notation discussions.

Rule mechanics

The capture is only possible when an opposing pawn makes a double-step from its starting rank (two squares) and ends on a square adjacent to the capturing pawn.
The capturing pawn must be on its own fifth rank (for white, the fifth rank is the row where it has advanced four times; for black, analogously on its fourth rank).
The capture is performed on the very next move, and it is recorded as the capturing pawn’s file plus the destination square followed by “e.p.” (for example, exd6 e.p. in the earlier scenario).
The captured pawn is removed from the board as if it had moved only one square.
If the immediate opportunity is not taken, the right to capture en passant disappears.

Notation and examples

En passant is indicated inalgebraic notation as a normal pawn capture followed by “e.p.” to distinguish it from a standard capture. The common example described above would be written exd6 e.p. after Black plays d7–d5 with a White pawn on e5 present to capture.

Historical context and practice

Origins

The en passant rule arose in the historical development of chess as the game adopted the two-square initial advance for pawns. As boards, pawns, and starting positions became standardized in the late medieval and early modern periods, the enforcement of en passant helped preserve the integrity of pawn structures and prevented artificial avoidance of capture. The exact documentary history is dotted with references across chess treatises, and the convention of the French term en passant became the dominant nomenclature in many languages.

Modern practice

Today, en passant remains a fundamental concept taught in chess curricula and is routinely encountered in games at all levels. It affects opening choices and midgame plans by enabling players to alter pawn structures, seize initiative, or simplify positions when appropriate. It also serves as a practical reminder that pawn structure and pawn breaks often determine the trajectory of the game, especially in open positions where queens and rooks can coordinate to exploit new weaknesses created by an en passant capture.