Bughouse chess

subject_name=Bughouse chess
setup_time= 1 minute
playing_time= Usually 5 to 10 minutes
skills=Chess strategy, Blitz chess
bggid= 14188

Bughouse chess (also called Exchange chess, Siamese chess, Tandem chess, Transfer chess, or simply Bughouse) is a popular chess variant played on two chessboards by four players in teams of two. [Other less common names for bughouse include Team chess, Hungarian chess, Swedish chess, New England Double Bughouse, Pass-On chess, Tandem Put-back, Double Speed, Double chess, Double Five, Simultaneous chess, Double Bug or Double Bughouse (von Zimmerman (2006), front; Manson and Hoover (1992), p. 186 and [http://www.chessvariants.com/multiplayer.dir/tandem.html Bughouse on Chessvariants] ). See [http://www.bughouse.be/bughouse%20translations.htm Bughouse in other languages] . Accessed July 29, 2007.] Normal chess rules apply, except that captured pieces on one board are passed on to the players of the other board, who then have the option of putting these pieces on their board.

The game is usually played at a fast time control; this, together with the passing and dropping of pieces, can make the game look chaotic and random to the casual onlooker; hence the name bughouse, which is slang for mental hospital. The game is traditionally played as a diversion from regular chess both over the board and online. Yearly, several dedicated bughouse tournaments are organised on a national and an international level.



bughouse chess diagram
A1=Team 1, Board A
A2=Team 2, Board A
B1=Team 1, Board B
B2=Team 2, Board B
= 8 |rd|nd|bd|qd|kd|bd|nd|rd|= 7 |pd|pd|pd|pd|pd|pd|pd|pd|= 6 | | | | | | | | |= 5 | | | | | | | | |= 4 | | | | | | | | |= 3 | | | | | | | | |= 2 |pl|pl|pl|pl|pl|pl|pl|pl|= 1 |rl|nl|bl|ql|kl|bl|nl|rl|= a b c d e f g h

8 |rl|nl|bl|kl|ql|bl|nl|rl|= 7 |pl|pl|pl|pl|pl|pl|pl|pl|= 6 | | | | | | | | |= 5 | | | | | | | | |= 4 | | | | | | | | |= 3 | | | | | | | | |= 2 |pd|pd|pd|pd|pd|pd|pd|pd|= 1 |rd|nd|bd|kd|qd|bd|nd|rd|= a b c d e f g h
Bughouse setup and start position

Bughouse is a chess variant played on two chessboards by four players in teams of two. Each team member faces one opponent of the other team. Partners sit next to each other and one player has black, while the other has white. Each player plays the opponent as in a standard chess game, with the exception of the rules specified below. [It should be noted though that bughouse has many variations and that there is no international standard. The rules below are in accordance with the [http://www.uschess.org/tournaments/2006/2006bughouse.pdf US chess federation] , the rules as applied on the chess servers Free Internet Chess Server and Internet Chess Club and the [http://bughouse.info Berlin bughouse tournament] . In the case rules contradict, alternatives are listed. Accessed July 29, 2007.]

Captured pieces

A player capturing a piece immediately passes that piece to the partner. The partner keeps these pieces in reserve and may, instead of playing a regular move, place one of these pieces on the board (as in shogi and crazyhouse). Pieces in reserve or on deck may be placed on a vacant square, the exception being pawns which may not be dropped on the first and last rank. Dropped pawns may promote, but all promoted pawns convert back to pawns when captured. In play over the board, a promoted pawn can be put on its side to indicate promotion. [von Zimmerman (2006), p. 15] A pawn placed on the second rank may move two squares on its first move. The reserve or stock should be kept in front of the board, always visible to all players of the game.

Clock and completion of a move

Bughouse chess is usually played with chess clocks to prevent players from waiting indefinitelyfor a piece. Clocks are placed on the outside so that each player can see both clocks. At thestart of the game, the players with the black pieces start the clocks simultaneously.Bughouse is usually played using clock move, which allows touching of pieces. A move is completed only when the clock is pressed. Touch move is practiced to a lesser extent. [See for example the [http://pion.ch/Bug/ruleseng.html rules of the Geneva bughouse tournament] . Accessed July 29, 2007.] When used, it applies to pieces in reserve as well; they are considered dropped after contact has been made with an empty square.

Bughouse can be played without a clock, but then there is usually a rule preventing a player waiting for pieces (stalling or sitting) indefinitely. One rule states that players may not delay their move beyond the time that it takes for their partner to make three moves. [http://www.chessvariants.com/multiplayer.dir/tandem.html Bughouse on ChessVariants.org] . Accessed July 29, 2007.]

End of the game

The match ends when either of the games on the two boards ends. A game is won when one playergets checkmated, resigns, forfeits on time or when an illegal moveis made in which the offending side is caught. The match can be drawn by agreement or when two players run out of time simultaneously. Depending on (local) rules threefold repetition applies, in which case the reserve of pieces is not taken into account. [For instance, the threefold repetition applies on FICS but not on Internet Chess Club.]

Alternatively, when one board finishes, play can continue on the other board. In this case, pieces in reserve can still be dropped, but no new pieces are coming in. The outcome of the match is then decided by adding the score of the two boards.


Partners are normally allowed to talk to each other during the game. They can for instance ask for a specific piece, for more trades, ask to hold a piece, suggest moves or ask their partner to stall. Shouts like "Gimme a knight, it mates!" or "Queen at any cost!" are common, and can lead to seemingly absurd sacrificial captures on the other board. It is however not allowed to physically act on the other board. [See Article nr. 12, [http://www.uschess.org/tournaments/2006/2006bughouse.pdf US chess federation Bughouse rules] . Accessed August 27, 2007.]


Bughouse comes in many variants, especially in the way drops are handled. Examples include: [ [http://www.chessvariants.org/index/listcomments.php?itemid=TandemChess Comments on tandem chess rules from chessvariants.com] . Accessed July 29, 2007.]
* Pieces cannot be dropped with check and/or checkmate. This variation is common in Europe and is sometimes referred to as tandem chess. [See for example the [http://www.pion.ch/Bug/rules.html bughouse rules from the Geneva gathering page] and the [http://www.schaakmeester-p.nl/spelregels.htm#doorgeefschaak official bughouse rules in the Netherlands] . Accessed July 29, 2007. ] [ [http://www.chessvariants.com/multiplayer.dir/tandem.html Tandem chess rules from chessvariants.com] . Accessed July 29, 2007.]
* Pieces can only be placed on the player's half of the board.
* Play continues until both games are complete.
* Kings can be captured and the game continues until one team has all kings on the board.
* Pawns cannot be dropped on seventh (and sometimes sixth) rank.
* Pawns never promote, when they reach the eighth rank they remain pawns. This was a common variation in Australia in the 1980s which saves having to find extra pieces.
* Pawns may be dropped on the first rank.

It is possible to play the game with just two players (one per team) by having each player move on two boards. Analogous to simultaneous chess, this way of playing the game is referred to as simultaneous bughouse. It can also be played with just one clock by playing the boards in a specific order (WhiteA, WhiteB, BlackB, BlackA) and pressing the clock after each move. This variation is suitable for play by mail. [von Zimmerman (2006), p.108]

Bughouse can be played with three or more boards. The game is played in exactly the same way as normal bughouse with boards placed with alternating colours and two players and one clock per board. On capturing a piece however, the player has to decide which player of the team will get that piece. In three board bughouse chess the middle player is the key since he gets material from two boards, but has to decide how to divide the captured pieces.Manson and Hoover (1992), p. 34–37] The middle board also commonly becomes very cramped due to having twice the number of pieces available.



In chess a minor material advantage is important as when material gets exchanged, the relative advantage becomes larger. Because new pieces come in, there is no endgame play in bughouse and material is therefore less important. It is common to sacrifice pieces in bughouse while attacking, defending or hunting down a certain piece which the partner requires.

A scoring system to evaluate material is to add up the piece values of the material on the board. In chess, when a pawn equals one unit, a bishop or knight is worth three, a rook five and a queen nine. These values are a consequence of the difference in mobility of the pieces. In bughouse piece values differ because pieces in reserve essentially have the same mobility as they can be dropped on any vacant square. [von Zimmerman (2006), p. 17.] The pawn relatively gains importance in bughouse chess, its very limited mobility does not handicap reserve pawns. They can for instance be dropped to block non-contact checks. Pawns can be dropped onto the seventh rank, one step away from promotion, which again adds to their importance. Long range pieces like the queen or the rook lose relative value, due to the constantly changing pawn structure. They are also more likely to be cornered in. [Manson and Hoover (1992), p. 32–33] A valuation system often applied to bughouse is pawn=1, bishop=knight=rook=2 and queen=4. [von Zimmerman (2006), p. 17. The bughouse playing program [http://sunsetter.sourceforge.net/ Sunsetter] uses the values pawn=100, bishop=195, knight=192, rook=200 and queen=390, while the engine [http://www.sjeng.org/indexold.html Sjeng] uses pawn=100, bishop=230, knight=210, rook=250 and queen=450. Accessed July 29, 2007.]


Captured pieces are passed on and thus what happens on one board, influences what happens on the other board. It is therefore natural for team members to communicate during game play. A common request of an attacking player would be "trades are good", while players in trouble would ask their partner to hold trades with "trades are bad". Equally a player can request a piece e.g. "knight wins a queen" or ask to hold a piece e.g. "rook mates me". [von Zimmerman (2006), p. 243–244]

Another common situation in the interplay between the two boards is a player not moving, also called sitting or stalling. This can happen in anticipation of a certain piece or at the request of the partner. Suppose a player is under heavy attack, and an additional pawn would mate him. When the partner cannot prevent giving up a pawn on the next move, sitting is the only strategy. It would of course be perfectly logical for the attacker to sit as well, waiting for a pawn to come. The situation, where diagonal opponents sit at the same time is known as a "sitzkrieg" (after the German for sitting war). The difference in time between the diagonal opponents will eventually force one party to move. This diagonal time advantage is more important than the difference on the clock between opponents on the same board. [Manson and Hoover (1992), p. 75–89]

Apart from this active communication, a good bughouse player tries to coordinate silently by keeping an eye on the other board and adapting moves accordingly. This can mean as little as glancing at the other board before trading queens, or as much as playing an opening adapted to the other board. [See Chris Ferrante (2000) [http://personal.atl.bellsouth.net/f/e/ferrantc/chess/bughouse.html] , reproduced in von Zimmerman (2006), p.79–94]

Attack and defense

Attacking the king can mean checking the opponent but also controlling vital squares around the king. It is an essential part of bughouse gameplay. From a player's perspective, attacking the king has important advantages as opposed to defending or attempting to win material: [von Zimmerman (2006), p.109]
* Because of the possibility of dropping pieces, attacks in bughouse can quickly lead to checkmate.
* The attacking player has the initiative, he is the one who controls the board, while the opponent is left to react. This has also important consequences for the other board.
* It is easier to attack than to defend. A defending mistake can have bigger consequences than an attacking mistake. Thus, the defender needs to be more precise, which in turn can lead to a time advantage for the attacker.It is common to sacrifice material to build up, or sustain an attack. Characteristic for attacks is the so-called "piece storm", where a player drops piece after piece with check. Contact checks, those that force the king to move, are especially important. They can be used to drive the king into the open, away from its defenders, while they prevent the opponent from putting new material on the board. [von Zimmerman (2006), p.20]

Partner communication is essential in a good defense. When one partner is under attack, the other partner should be aware of which pieces hurt most. Sitting strategies might be necessary, and it is therefore important to play the defense fast. Accepting a sacrifice can be lethal. On the other hand, it results in the attacker having a piece less to play with, with the defender's partner having a piece more. Sacrifices therefore give the partner of the defender an opportunity to take initiative. [von Zimmerman (2006), p.113]


There are significantly fewer bughouse openings than there are chess openings. Many chess openings create weaknesses which can be easily exploited in bughouse. It is for instance not recommended to move pawns other than the d and e pawn. [von Zimmerman (2006), p.21–24] Bughouse openings are generally geared towards dominating vital squares and fast development. Captured pieces become available after the first few moves and it is important to develop at this stage as there is often not enough time to do so later. Development also helps to defend against early piece drop attacks. [von Zimmerman (2006), p.68]

In typical chess openings, kings castle. For all but expert players, this is generally not recommended in the opening stage of a bughouse game. A castled king is trapped on one side of the board, and is therefore inherently harder to defend. There are also fewer escape routes possible.

Notation and sample game

The algebraic chess notation for chess can be used to record moves in bughouse games.Different notations for piece drops are possible.Manson and Hoover (1992) use an "x" (as used in captures) in front to indicate a piece drop, as in xNf1. Penn and Dizon (1998) use the "I" (for insert) in front as in INf1. Von Zimmerman (2006) uses the @-notation. The internet chess servers FICS and Internet Chess Club use the at-sign @, as in N@f1 (knight drop at f1), Q@e6+ (queen drop with check at e6) or P@h7 (pawn drop at h7).

Because of the fast pace at which the game is played, bughouse games are rarely recordedin games played over the board. With the arrival of online chess it has become possible to systematically record games. [Two large bughouse databases are [http://www.bughouse-db.org Jamesbaud's database] and [http://www.bughouse.be/database.html Lieven's database] .Accessed July 31, 2007.] The format in which this is done is the bughouse portable game notation (BPGN), an extension of the Portable Game Notation for chess. [http://www.bughouse.be/BPGN_Standard.txt Specification of the BPGN format from bughouse.be] . Accessed July 29, 2007. Software, such as BPGN viewer can be used to replay and analyse bughouse games.BPGN viewer can be obtained from [http://www.bughouse.net/ bughouse.net] . Accessed July 29, 2007. Below is an example bughouse game in the BPGN format.

[Event "rated bughouse match"] [Site "chess server X"] [Date "2004.04.12"] [WhiteA "WA"] [WhiteAElo "1970"] [BlackA "BA"] [BlackAElo "2368"] [WhiteB "WB"] [WhiteBElo "1962"] [BlackB "BB"] [BlackBElo "2008"] [TimeControl "180+0"] [Result "0-1"] 1A. e4 {180} 1a. Nc6 {180} 1B. d4 {179} 2A. Nc3 {179} 1b. Nf6 {178} 2a. Nf6 {178} 2B. d5 {178} 3A. d4 {177} 2b. e6 {177} 3a. d5 {177} 3B. dxe6 {176} 4A. e5 {176} 3b. dxe6 {176} 4B. Qxd8+ {175} 4a. Ne4 {175} 4b. Kxd8 {175} 5B. Bg5 {174} 5A. Nxe4 {174} 5a. dxe4 {173} 5b. Be7 {173} 6A. Nh3 {173} 6B. Nc3 {172} 6a. Bxh3 {171} 6b. N@d4 {171} 7A. gxh3 {171} 7a. Nxd4 {170} 7B. O-O-O {169} 8A. P@e6 {168} 7b. Nbc6 {168} 8B. Bxf6 {166} 8a. N@f3+ {165} 9A. Qxf3 {165} 8b. Bxf6 {164} 9a. Nxf3+ {164} 10A. Ke2 {164} 9B. e3 {164} 10a. Q@d2+ {164} 11A. Bxd2 {164} 11a. Qxd2+ {164} {WA checkmated} 0-1

Where to play

Over the board

Little is known on the history of bughouse, but it seems to have developed in the early 1960s. Pritchard (2007), p. 327 ] It is now quite popular as a diversion of regular chess in local chess clubs throughout Europe and the US. [von Zimmerman (2006), p.162–173] Grandmasters such as Levon Aronian, Joel Benjamin, Yasser Seirawan, Andy Soltis, John Nunn, Jon Speelman, Sergey Karjakin, Michael Adams, Emil Sutovsky and Michael Rohde have been known to play the game. [John Nunn playing bughouse at the 2004 World Chess Solving Championship; [http://www.chessbase.com/newsdetail.asp?newsid=1919 Chessbase news, 22 September 2004] . Accessed July 29, 2007.] [Sergey Karjakin playing bughouse at the 2005 Young Stars tournament; [http://www.chessbase.com/newsdetail.asp?newsid=2423 Chessbase news 31, May 2005] . Accessed July 29, 2007.] [ Bughouse Newsletter, Vol I 1992 edited by Jeremy Graham] [ [http://findarticles.com/p/articles/mi_qn4158/is_19990712/ai_n14255436 The Independent (London), 12 July 1999] . Accessed July 29, 2007. ] [ [http://chesspro.ru/_events/2007/monreal13.html Emil Sutovsky playing bughouse at the 8th Montreal International] Accessed July 31, 2007.]

With the absence of an International Federation, competitive over the board bughouse is very much in its infancy. There is also no world championship. A few countries do organize bughouse tournaments within the national chess federation. Examples include:
* The yearly international chess festival Czech Open in July features the Czech republic bughouse championship. [ [http://www.czechopen.net/ Chess festival Czech Open] . Accessed July 29, 2007.]
* Yearly, USCF organizes bughouse tournaments as part of the National Junior High (K-9) Championship and the National High School (K-12) Championship. [The official announcements for the [http://www.uschess.org/tournaments/2006/jhs/ 2006] and [http://www.uschess.org/tournaments/2007/jhs/ 2007] editions. Accessed July 29, 2007.] [The official announcements for the [http://www.uschess.org/tournaments/2006/hs/ 2006] and [http://www.uschess.org/tournaments/2007/hs/ 2007] editions. Accessed July 29, 2007.] Other tournaments are organized privately:
* One of the largest international bughouse tournaments is the yearly tournament in Berlin. [ [http://www.bughouse.info Official website of the Berlin bughouse tournament] . Accessed July 29, 2007.] Going into its sixth edition, it is popular among top players from FICS. Grandmaster Levon Aronian took part in the 2005 edition of the tournament and took the second place with his teammate Vasiliy Shakov. [ [http://www.berlinerschachverband.de/archiv/chronik/2005/tandem/ Report of the 2005 edition] , Berliner Schachverband. Accessed July 29, 2007.]
* Since 2000 there has been an annual bughouse tournament in Geneva, attracting the best European players. [ [http://www.pion.ch/Bug/gath.html Official site of the bughouse tournament in Geneva] . Accessed July 29, 2007.]


Bughouse can be played online at chess servers such as FICS and ICC since 1995. [von Zimmerman (2006), p.239] FICS is currently the most active server for bughouse, attracting world's best players. These include Levon Aronian, Maarten Aronsson, Igor Bjelobrk, Jeremy Keller, Kazim Gulamali, André Nilsson, Peter Minear and Linus Olsson. [von Zimmerman (2006), p.5–9, 16, 25, 95 and 240]

The game is played online in the same way as over the board, but some aspects are unique to online bughouse. In games over the board, communication is heard by all players, while in online bughouse it is usually done via private messages between two partners. This makes communication a more powerful weapon. It is also easier to coordinate as the second board is more visible on the screen than over the board. [von Zimmerman (2006), p.240] The time aspect is altered due to existence of premove and lag. The latter can influence the diagonal time difference significantly, and it is good sportsmanship to restart the game when this difference gets too large. [Anders Ebenfelt's [http://www.geocities.com/Paris/Metro/1324/ Bughouse page] . Accessed August 29.]

ICS compatible interfaces particularly suitable for bughouse include Thief and BabasChess. They have the ability to display both boards at the same time and store played or observed games, they also have partner communication buttons and a lag indicator. Special Xboard compatible engines have been written that support bughouse, examples are Sunsetter, Sjeng and TJchess. [ [http://sunsetter.sourceforge.net/ Homepage of Sunsetter] . Accessed July 29, 2007.] [ [http://www.sjeng.org/indexold.html Homepage of Sjeng] . Accessed July 29, 2007. ] [ [http://www.tonyjh.com/chess/ Homepage of TJchess] . Accessed July 29, 2007.] Although much faster than humans, they lack in positional understanding and especially in coordination and communication, an essential skill in this team game. [Georg von Zimmerman (2000), "Figuren recycling", Computerschach und Spiele 5/00 p44–46 (in German).]


Bughouse chess is controversial among scholastic chess teachers. The majority view is that it does not have a positive effect on novice chess players. [ [http://www.uschess.org/scholastic/sc-guide2.html A guide to scholastic chess] , United States Chess Federation. Accessed October 3, 2007.] In the words of Susan Polgar: "If your children want to play bughouse for fun, it is OK. But just remember that it is not chess and it has no positive value for chess. In fact, I absolutely recommend no bughouse during a tournament." [ [http://main.uschess.org/content/view/7794/302/ Scholastic Chess: Polgar Girls' World Open and Boys' Chess Challenge] , USCF Chess Live Magazine. Accessed October 3, 2007.] One argument supporting this view is that bughouse distorts the typical pattern recognition used in chess. [cite book | author=Snyder, Robert M.| title=Winning Chess Tournaments for Juniors|publisher=Random House Puzzles & Games| year=2004 | id=ISBN 978-0812936353, p. 10.] Another argument is that bughouse neglects positional values due to its highly tactical game play.von Zimmerman (2006), p. 27] On the other hand, there is no evidence that bughouse would hurt experienced chess players. In the words of Levon Aronian: "Bughouse is good for players who know chess well already. ... I started to play bug when I was already at master level, [you] see, and I think bughouse is good for the imagination, to develop new ideas."



*Harvard reference
surname1=Manson Jr.
given1=John F.
title=Siamese Chess. How To Play...How to Win!
publisher=Farnsworth Enterprises

*Harvard reference
given1=David A.
title=Comprehensive Bughouse Chess
publisher=Graham Cracker Studios

*Harvard reference
given=D. B.
authorlink=David Pritchard (chess writer)
title=The Classified Encyclopedia of Chess Variants. (second edition)
publisher=John Beasley

*Harvard reference
editor-last=von Zimmerman
title=Bughouse Chess
publisher=Books on Demand GmbH

External links

* [http://www.chessvariants.org/multiplayer.dir/tandem.html Bughouse on the ChessVariants pages]
* [http://personal.atl.bellsouth.net/f/e/ferrantc/chess/index.html Errant Fischer's Bughouse Page]
* [http://www.thebugboard.net/ The Bug Board - Forum and software]
* [http://www.bughouse-db.org/ bughouse-db.org - FICS bughouse database]
* [http://www.bughouse.be/ bughouse.be - Database and links]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • bughouse chess — noun A variant of chess played on two chessboards by four players in teams of two. Each player plays the other colour of pieces than his team mate, to whom he passes the pieces he captures from his opponent. The teammate can then choose to put… …   Wiktionary

  • Bughouse — can refer to several things:* A psychiatric hospital * Bughouse chess * Operation Bughouse , an alternate name for the fictional Battle of Klendathu …   Wikipedia

  • Bughouse — Blitz à quatre joueurs de blitz à quatre Le blitz à quatre est une variante du jeu d échecs populaire, et aussi connue sous d autres appellations variées, comme tandem[1]. Elle consiste à jouer en deux équipes de deux joueurs sur deux éc …   Wikipédia en Français

  • Chess variant — Gliński s hexagonal chess – one of many chess variants A chess variant is a game related to, derived from or inspired by chess.[1] The difference from chess might include one or more of the following: different board (larger or smaller, non… …   Wikipedia

  • Chess Engine Communication Protocol — The Chess Engine Communication Protocol is an open communication protocol that enables a chess engine to communicate with its user interface. It was designed by Tim Mann, the author of XBoard. It was initially intended to only communicate with… …   Wikipedia

  • Glossary of chess — See also: Outline of chess and Glossary of chess problems This page explains commonly used terms in chess in alphabetical order. Some of these have their own pages, like fork and pin. For a list of unorthodox chess pieces, see fairy chess… …   Wikipedia

  • List of chess terms — This page explains commonly used terms in chess in alphabetical order. Some of these have their own pages, like fork and pin. For a list of unorthodox chess pieces, see fairy chess piece; for a list of terms specific to chess problems, see chess… …   Wikipedia

  • Outline of chess — A game of chess, in the starting position. See also: Glossary of chess and Index of chess articles The following outline is provided as an overview of and topical guide to chess: Chess – two player board game played on a chessboard, a square …   Wikipedia

  • Index of chess articles — Contents 1 Books 2 General articles 2.1 0–9 2.2 A …   Wikipedia

  • List of chess books — This is a list of chess books that are used as references in articles related to chess. The list is organized by alphabetical order of the author s surname, then the author s first name, then the year of publication, then the alphabetical order… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.