En passant (from French: in passing) is a move in the board game of chess. It is a special pawn capture which can occur immediately after a player moves a pawn two squares forward from its starting position, and an enemy pawn could have captured it had the same pawn moved only one square forward. The opponent captures the just-moved pawn as if taking it "as it passes" through the first square. The resulting position is the same as if the pawn had moved only one square forward and the enemy pawn had captured normally.
The en passant capture must be done on the very next turn, or the right to do so is lost. Such a move is the only occasion in chess in which a piece captures but does not move to the square of the captured piece. If an en passant capture is the only legal move available, it must be made. En passant capture is a common theme in chess compositions.
This rule was added in the 15th century when the rule giving pawns the option of initially moving two squares was introduced. It prevents a pawn from using the two-square advance to pass an adjacent enemy pawn without the risk of being captured.
|This article uses algebraic notation to describe chess moves.|
The rule 
- the capturing pawn must be on its fifth rank
- the captured pawn must be on an adjacent file and move two squares in a single move (i.e. a double-step move)
- the capture can only be done immediately after the opposing pawn makes the double-step move (if not done then, the right to capture it en passant is lost)
Black to move
White to move
Black to move
Such a move is the only occasion in chess in which a piece captures but does not move to the square of the captured piece.:463
In the opening 
- 1. e4 e5
- 2. Nf3 Nf6
- 3. d4 exd4
- 4. e5 Ne4
- 5. Qxd4 d5 (diagram)
- 6. exd6 :124–125.
Another example occurs in the French Defense after 1.e4 e6 2.e5, a move once advocated by Wilhelm Steinitz.:2 If Black responds with 2...d5, White can capture the pawn en passant with 3.exd6. Likewise, White can answer 2...f5 with 3.exf6.
- 1.e4 e6
- 2.e5 d5
- 3.exd6 e.p.
Unusual examples 
- 13. h5+ Kh6
- 14. Nxe6+
Note that the bishop on c1 effects the check, via a discovered check. 14...Kh7 results in 15.Qxg7#.
- 14... g5
- 15. hxg6e.p.#
The en passant capture and discovered checks place Black in checkmate (from White's rook on h1, even without help from White's bishop).
The largest known number of en passant captures in one game is three, shared by three games; in none of them were all three captures by the same player. The earliest known example is a 1980 game between Alexandru Sorin Segal and Karl Heinz Podzielny.:98–99
In chess compositions 
En passant captures have often been used as a theme in chess compositions, as they "produce striking effects in the opening and closing of lines".:106 In the 1938 composition by Kenneth S. Howard, the key move 1.d4 introduces the threat of 2.d5+ cxd5 3.Bxd5#. Black may capture the d4-pawn en passant in either of two ways:
- The capture 1...exd3e.p. shifts the e4-pawn from the e- to the d-file, preventing an en passant capture after White plays 2.f4. To stop the threatened mate (3.f5#), Black may advance 2...f5, but this allows White to play 3.exf6e.p. with checkmate due to the decisive opening of the e-file.
- If Black plays 1...cxd3e.p., White exploits the newly opened a2–g8 diagonal with 2.Qa2+ d5 3.cxd6e.p.#
Historical context 
Allowing the en passant capture is one of the last major rule changes in European chess that occurred between 1200 and 1600, together with the introduction of the two-square first move for pawns, castling, and the unlimited range for queens and bishops.:14,16,57 Spanish master Ruy López de Segura gives the rule in his 1561 book Libro de la invencion liberal y arte del juego del axedrez.:108 In most places the en passant rule was adopted as soon as the rule allowing the pawn to move two squares on its first move, but it was not universally accepted until the Italian rules were changed in 1880.:124-125
The motivation for en passant was to prevent the newly added two-square first move for pawns from allowing a pawn to evade capture by an enemy pawn.:16. Asian chess variants, because of their separation from European chess prior to that period, do not feature any of these moves.
In either algebraic or descriptive chess notation, en passant captures are sometimes denoted by "e.p." or similar, but such notation is not required. In algebraic notation, the move is written as if the captured pawn just advanced only one square, e.g., bxa3 (or bxa3e.p.) in this example.:216
Threefold repetition and stalemate 
The possibility of an en passant capture has an effect on claiming a draw by threefold repetition. Two positions whose pieces are all on the same squares, with the same player to move, are considered different if there was an opportunity to make an en passant capture in the first position, because that opportunity by definition no longer exists the second time the same configuration of pieces occurs.:27
In his book about chess organization and rules, International Arbiter Kenneth Harkness wrote that it is frequently asked if an en passant capture must be made if it is the only move to get out of stalemate.:49 This point was debated in the 19th century, with some arguing that the right to make an en passant capture is a "privilege" that one cannot be compelled to exercise. In his 1860 book Chess Praxis, Howard Staunton wrote that the en passant capture is mandatory in that instance. The rules of chess were amended to make this clear. Today, it is settled that the player must make that move (or resign). The same is true if an en passant capture is the only move to get out of check.:49
See also 
- Brace, Edward (1977), "en passant", An Illustrated Dictionary of Chess, Craftwell, ISBN 1-55521-394-4
- FIDE rules (En Passant is rule 3.7, part d)
- Burgess, Graham (2000), The Mammoth Book of Chess (2nd ed.), Carroll & Graf, ISBN 978-0-7867-0725-6
- Hooper, David; Whyld, Kenneth (1992), "en passant", The Oxford Companion to Chess (2nd ed.), Oxford University Press, ISBN 0-19-866164-9
- Minev, Nikolay (1998), The French Defense 2: New and Forgotten Ideas, Thinkers' Press, ISBN 0-938650-92-0
- Steinitz vs. Fleissig, 1882
- Gundersen vs. Faul. ChessGames.com. Retrieved on 2009-06-12.
- Winter, Edward (1999), Stalemate, Chesshistory.com, retrieved 2009-06-12
- A. Segal vs. K. Podzielny, Dortmund 1980. Published by 365Chess.com. Retrieved on 2009-12-05.
- Howard, Kenneth S. (1961), How to Solve Chess Problems (2nd ed.), Dover, ISBN 978-0-486-20748-3, retrieved 2009-11-30
- Davidson, Henry (1949), A Short History of Chess (1981 paperback ed.), McKay, ISBN 0-679-14550-8
- Golombek, Harry (1977), "en passant, capture", Golombek's Encyclopedia of Chess, Crown Publishing, ISBN 0-517-53146-1
- Schiller, Eric (2003), Official Rules of Chess (2nd ed.), Cardoza, ISBN 978-1-58042-092-1
- Harkness, Kenneth (1967), Official Chess Handbook, McKay, ISBN 1-114-15703-1