A coup en passant is the lead of a plain suit card to promote a low trump card behind a higher trump card to a winning position. It describes an action taken by the declarer to promote a trump card of lesser value than the trump card held by a defender.

Note: The expression comes from the French language and is translated into English as coup in passing. The term stems from the French verb passer meaning to pass. The term en passant, as an adverb, dates from the year 1665 and is generally employed to describe an action of a chess player, namely the capture of a pawn as it makes a first move of two squares by an enemy pawn that threatens the first of these squares.

A coup en passant is the simplest type of a situation called an elopement.

Note: The designation elopement was coined by Mr. Géza Ottlik, (born May 9, 1912 and died October 9, 1990), of Budapest, Hungary, in a series of articles for the bridge-related magazine The Bridge World beginning in December 1967 to describe coups by which a player scores a trick or tricks with trumps that would not ordinarily have sufficient rank to take a trick.

The following illustration should clarify the concept.

	North 43
West QJ		East 10 A
	South 6   4

The contract is Spades. The lead is from North, with South as the declarer.

South has no winning cards, but when South leads a Heart from the dummy, East must decide whether to play the ten of Spades, taking the trick by trumping, or discard the Ace of Diamonds.

If East decides to play the ten of Spades, then South wins an additional trick with the six of Spades, the trump suit.

If East decides to discard the Ace of Diamonds, then South ruffs with thesSix of Spades, the trump suit. This action is called the coup en passant.

Other examples of coups en passant can be found at bridgebum.com,

71st Summer North American Bridge Championships
Date: July 21 - July 31, 1999
Daily Bulletin, Saturday, July 31, 1999, Vol. 71, No.10

The Daily Bulletin describes a coup en passant as executed by Mr. Bob Schartz on the following outlined board. The text is quoted.

Bob Schwartz found a neat play on this deal to bring home a tough contract.

	North K93 KQ102 A5 AK63
West QJ108 A654 J9754		East A6 J9873 KJ74 108
	South 7542   Q1098632 Q2

Dealer: North
Vulnerable: E-W
West		North		East		South		Meaning
Schwartz		1						Strong, artificial and forcing.
				1				Hearts or the black suits
						Pass
3								Pass or correct.
		Pass		Pass		Pass

North cashed the top clubs, then tried the Ace and was more hurt than surprised when Schwartz ruffed. Now the Ace brought the very bad news, but Bob recovered nicely.

He ran the Queen (North accurately ducking), then led a good club to pitch the Ace. The Jack was covered and ruffed, and now a diamond ruff and a good club led to this ending:

	North 9 KQ10
West 108 6 5		East   J98 K
	South 75   Q10

Bob led the 5, and North was toast. If North discarded or ruffed low, Schwartz would have no problem, so he ruffed high. Schwartz carefully underruffed and was in a position to get back to his hand no matter which plain card North had to go with his hearts. If it was a spade, Schwartz would simply ride it around to his hand. If it was a King, Schwartz could ruff his good diamond king to leave himself in the proper hand to catch North in a coup en passant to make the Jack.

If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.