En passant

This article is about the move in chess. For other uses, see En passant (disambiguation).

The en passant (French: [ɑ̃ paˈsɑ̃], lit. in passing) capture is a move in chess. It is a capture by a pawn of a horizontally adjacent enemy pawn that has just made a two-square move. The capturing pawn moves to the square that the enemy pawn passed; the enemy pawn is captured as if it had advanced only one square. Such a capture is permitted only on the turn immediately after the enemy pawn’s two-square advance. En passant is the only capture in chess where the capturing piece does not take the captured piece's place.

The en passant rule was added in the 15th century alongside the introduction of the pawn's initial two-square advance. It prevents a pawn from using the advance to bypass the risk of being captured by an enemy pawn. En passant is a common theme in chess problems.

Rules

Animation of an en passant capture

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

• Both of the pawns occupy the same rank.
• The capturing pawn is adjacent to the enemy pawn.
• The enemy pawn moved two squares on the previous move. (If the right to capture en passant is not exercised immediately, it is subsequently lost.)

If these conditions are met, the capturing pawn may move to the square that the enemy pawn passed, capturing the enemy pawn as if it had moved only one square.

Example of en passant

Black to move a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h The black pawn is on its initial square. If it moves to f6 (marked by ×), the white pawn can capture it.

White to move a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Black moves their pawn forward two squares in a single move from f7 to f5, "passing" f6.

Black to move a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h White captures the black pawn en passant, as if it had moved only one square to f6.

Only pawns may capture or be captured en passant; other pieces with the ability to capture diagonally—the king, queen, and bishop—cannot perform the capture. En passant is the only capturing move in chess such that the capturing piece is moved to a square other than that occupied by the captured piece.

Notation

In algebraic and descriptive chess notation, an en passant capture is notated using the capturing pawn's destination rather than the captured pawn's location. En passant may optionally be denoted by e.p. or similar. For example, bxa3 or bxa3 e.p. may be used to represent a black pawn on b4 capturing a white pawn on a4 en passant.

Examples

In the opening

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Black just played 5...d7–d5. White's e5-pawn can capture en passant.

Some chess openings feature en passant. In the following line from Petrov's Defence, White can capture the pawn on d5 en passant on their sixth move:

1. e4 e5

2. Nf3 Nf6

3. d4 exd4

4. e5 Ne4

5. Qxd4 d5 (see diagram)

6. exd6 e.p.

Steinitz vs. Fleissig, 1882

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position after 3.exd6 e.p.

Another example occurs in the French Defence after 1.e4 e6 2.e5, a line advocated by Wilhelm Steinitz. If Black responds with 2...d5, White can capture the pawn en passant with 3.exd6 e.p.; likewise, White can answer 2...f5 with 3.exf6 e.p. The former line occurred in a game between Steinitz and Bernhard Fleissig (see diagrammed position).

Unusual examples

An example of overlooking
capturing en passant

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Black to move. Here 1...g5+? loses to an en passant checkmate.

In the diagram, the move 1...g5+ seems to checkmate White, but it is in fact a blunder. Black overlooks that White can counter this check with the en passant capture 2.fxg6 e.p.#, which cross-checks and checkmates Black. (1...Qxf2+ instead draws.)

Gundersen vs. Faul, 1928

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Position after 12...f7–f5

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h After 14...g7–g5. White mates by taking the pawn en passant.

In a game between Gunnar Gundersen and Albert H. Faul, Black played 12...f7–f5. White could have captured the black f-pawn en passant with his e-pawn, but he instead played:

13. h5+ Kh6 14. Nxe6+

The bishop on c1 effects a discovered check. 14...Kh7 results in 15.Qxg7#.

14... g5 15. hxg6 e.p.#

The en passant capture and discovered checks place Black in checkmate (in fact, White's bishop is not necessary for the mate). An en passant capture is the only way a double check can be delivered without one of the checking pieces moving, as in this case.

The largest known number of en passant captures in one game is three. This record is 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.

In chess problems

Kenneth S. Howard, 1938

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

White to play and mate in three

En passant is often used as a theme in chess problems; according to Kenneth S. Howard, "En passant pawn captures frequently produce striking effects in the opening and closing of lines." In the diagrammed 1938 composition by Howard, the key 1. d4 introduces the threat of 2.d5+ cxd5 3.Bxd5#. Black can capture the d4-pawn en passant in either of two ways:

• The capture 1... exd3 e.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 can advance 2... f5, but this allows White to play 3. exf6 e.p. with checkmate due to the decisive opening of the e-file.
• If Black plays 1... cxd3 e.p., White exploits the newly opened a2–g8 diagonal with 2. Qa2+ d5 3. cxd6 e.p.#

O. Sommerfeldt, 1902

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

White to play and mate in two

The diagrammed 1902 composition by Sommerfeldt shows the effect of pins on en passant captures.

The key

 1. d4!

threatens 2.Qf2#. The moves of the black e-pawn are restricted in an unusual manner. The en passant capture 1...exd3 e.p.+ is illegal (it exposes Black’s king to check), but

 1... e3+

is legal. This, however, removes the black king's access to e3, allowing

 2. d5#

History

The en passant rule, along with the pawn’s two-square first move, was introduced between the 13th and 16th centuries; it was one of the last major additions to European chess. The rule was added to prevent a pawn from using the newly added two-square first move to evade capture by an enemy pawn. In most places, the en passant rule was adopted at the same time as the pawn's two-square initial move, but it was not universally accepted until the Italian rules were changed in 1880.

In chess variants

In most chess variants, pawns move as in standard chess, so the en passant rule is the same. Some larger variants allow pawns to make an initial move of more than two squares, such as the 16×16 game chess on a really big board, in which pawns may move up to six squares forward; such games usually allow an en passant capture on any square the pawn passes.

In some three-dimensional chess variants, such as millennium 3D chess or Alice chess, en passant is allowed, though in the former case, the captured pawn's two-square move cannot have been purely vertical. In 5D Chess with Multiverse Time Travel, en passant is allowed in the spatial dimensions but not between universes or across time.

Some fairy chess pieces can capture en passant, such as the Berolina pawn.

En passant is absent in some chess variants, such as Dragonchess and Raumschach, as well as the Asian variants shogi, xiangqi, and janggi. In these games, pawns (soldiers in xiangqi and janggi) do not have an initial two-square advance, and in the Asian variants, they cannot even capture diagonally.

Draw by repetition and stalemate

In the context of threefold and fivefold repetition, two positions are considered different if the opportunity to perform a given en passant capture exists in one position but not the other.

If en passant is a player's only legal move, they must either perform it or end the game on their turn via normal means; the player is forbidden to "claim" a draw by stalemate, regardless of whether or not they are in check. In his book on chess organization and rules, International Arbiter Kenneth Harkness wrote that people frequently asked if this is the case. Chess players debated this point in the 19th century, with some arguing that the right to capture en passant 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 such a position; the rules of chess were amended to make this clear.

References

Bibliography

• Just, Tim; Burg, Daniel B. (2003), U.S. Chess Federation's Official Rules of Chess (5th ed.), McKay, ISBN 0-8129-3559-4
• Winter, Edward (2006), Chess Facts and Fables, McFarland, ISBN 0-7864-2310-2