A chess variant is a game derived from, related to or similar to chess in at least one respect.^[1] The difference from chess can include one or more of the following:

• Different board (larger or smaller, non-square board shape overall or different spaces used within the board such as triangles or hexagons instead of squares).
• Fairy pieces different from those used within chess.
• Different rules for capture, move order, game goal, etc.

National chess variants which are older than Western chess, such as chaturanga, shatranj, xiangqi, and shogi, are traditionally also called chess variants in the Western world. They have some similarities to chess and share a common ancestor game.

The number of possible chess variants is unlimited. D.B. Pritchard, the author of Encyclopedia of Chess Variants, estimates that there are over 2000 chess variants,^[2] confining the number to published ones.

In the context of chess problems, chess variants are called fantasy chess, heterodox chess or fairy chess. Some chess variants are used only in chess composition and not for playing.

Contents 1 Chess-derived games 1.1 Chess with different starting positions 1.2 Chess with different forces 1.3 Chess with different boards 1.4 Chess with unusual rules 1.5 Chess with incomplete information or elements of chance 1.6 Multimove variants 1.7 Multiplayer variants 1.8 Chess with unusual pieces 1.8.1 Bishop+knight and rook+knight compounds 1.9 Games inspired by chess 2 Chess-related historic and regional games 2.1 Historic chess-related games 2.2 Regional chess-related games 3 Chess variants software 4 Notes 5 References 6 See also 7 External links 7.1 General 7.2 Collections

[edit] Chess-derived games

These chess variants are derived from chess by changing the board, pieces or rules.

[edit] Chess with different starting positions

In these variants, the starting position is different, but otherwise the board, pieces and rules are the same. The most important motivation for these chess variants is to nullify established opening knowledge.

• Chess960 (or Fischer random chess): the placement of the pieces on the 1st rank is randomized, and the pieces on the 8th rank mirror it.
• Displacement chess: some pieces in the initial position are exchanged but the rules remain exactly the same. Some examples of this may be that the king and queen are flipped, or the b knight is traded with the f bishop.
• Transcendental chess: similar to chess960, but the opening white and black positions do not mirror each other.
• Upside-down chess. The black and white pieces are switched so that all the pawns are one step away from getting promoted.^[3] The game can start, for example: 1. Nc6 Nf3 2. b8Q g1Q etc.

One of the 960 openings in Chess 960

Upside-down chess

[edit] Chess with different forces

Some chess variants use different number of pieces for white and black. All pieces in these games are standard chess pieces, there are no fairy chess pieces.

• Dunsany's chess (or Horde chess): one side has standard chess pieces, and the other side has 32 pawns.
• Handicap chess (or chess with odds): variations to equal chances of players with different strength.
• Pawns game. In the starting position white does not have a queen, but has eight additional pawns (see diagram below). The game was played by such old masters as Labourdonnais, Deschappelles and Kieseritsky.^[4]
• Peasant's revolt by R.L.Frey (1947). White has a king and eight pawns (the peasants) against king, pawn and four knights by black (the nobles).^[5] An alternate setup is that the knight next to the king is taken. There is still another alternate set up used for mental training.
• Pheasant, this is similar to Peasant's revolt, only black has only two knights and they are set in the same position as a normal chess game, along with the King in the normal starting position and the King's pawn only. White still has the King and eight pawns.
• Weak!. White has usual pieces, black has king, seven knights and sixteen pawns. This game was played at Columbia University chess club in the 1960s.^[6]
• Marxist Game used by Jose Fadul of De La Salle-College of Saint Benilde as mental training , together with the Republican Game, the Atheist Game, and the other alternate set up for the Peasants' revolt.^[7]

Pawns game

Peasant's revolt

Alternate setup for Peasant's revolt

Weak!

Marxist game

Republican game

Atheist game

Another Alternate Set up for Peasants' revolt

[edit] Chess with different boards

In these chess variants the same pieces and rules as in chess are used, but the board is different. It can be smaller or larger, non-square overall or based upon triangle or hexagon spaces (instead of square spaces). The movement of pieces in some variants is modified to account for the unusual property of the playing board.

• Active Chess: Played on a 9x8 board, an extra Queen is placed with an extra pawn in front. This version was invented by G. Kuzmichov in 1989. This was researched by his students. They decided the best opening array for a 9x8 board was a second queen either on file 8 or file 9.
• Alice chess: played with two boards. A piece moved on one board passes "through the looking glass" onto the other board.
• Circular chess: played on a circular board consisting of four rings, each of sixteen squares.
• Cylinder chess: played on a cylinder board with A and H files "connected". Thus a player can use them as if the A file were next to the H file (and vice versa).
• Doublewide chess: two or four regular chess boards are connected (for a 16x8 or 16x16 play surface) and each player plays with two complete sets of chess pieces. Because each player has two kings, the first king can be captured without ending the game.^[8]
• Flying chess: This is played on a board of 8x8x2, giving a total of 128 cells. Only certain pieces can move to and from the additional level.
• Gravity chess: Rules are the same as in regular chess, except that all pieces are gravitationally "attracted" to the h-file (or a-file, depending on variants). This means that whenever there is free space between a piece and the h-file, the piece moves as far as it can to the h-file until the free space runs out.
• Grid chess: the board is overlaid with a grid of lines. For a move to be legal, it must cross at least one of these lines.
• Hexagonal chess: a family of chess variants played on a hexgrid with three colours and three bishops.
• Infinite chess: has a board shaped like the infinity symbol. It is connected at the center, and all pieces of the traditional chess are used.^[9]
• Lord Loss chess: played on five different boards with two players. One person moves a piece on any board and his/her opponent can choose to move on a different or the same board. The game is featured in the book Lord Loss by Darren Shan.
• Los Alamos chess (or Anti-Clerical chess): played on a 6x6 board without bishops. This was the first chess-like game played by a computer program.
• Millennium chess: similar to Doublewide chess. Two boards are connected side by side; however, in this variant the middle files are merged, making a 15x8 board.^[10]
• Minichess: a family of chess variants played with regular chess pieces and standard rules, but on a smaller board.
• Three-dimensional chess: several variants exist with the most commonly known being "Tri-D chess" from the television series Star Trek as well as an easily playable 3x8x8 variant known as Millennium 3D chess.

[edit] Chess with unusual rules

• Absorbtion Chess: A capturing piece gains the movement abilities of the piece it is capturing. Therefore if a Rook captured a Bishop, the Rook would then be able to move like a Queen as it can move like the Rook and now the Bishop. This rule does not apply to Kings and Pawns.
• Absorbtion Chess II: Similar to the original Absorbtion Chess. A capturing piece gains the movement abilities of the piece it is capturing. This rule DOES apply to Kings and Pawns.
• Accelerated Chess: Each player makes two non-capturing moves or one capturing move in each turn.
• Andernach chess: a piece making a capture changes colour.
• Atomic chess: any capture on a square results in an "atomic explosion" which kills (i.e. removes from the game) all pieces in any of the eight surrounding squares, except for pawns.
• Benedict chess: pieces are not allowed to be "captured". If a piece when moved could capture an opposing piece in its next move, that opposing piece changes sides.^[11]
• Checkers chess: normal rules of chess are followed. However, pieces can only move forwards until they have reached the far rank.
• Checkless chess: players are forbidden from giving check except to checkmate.
• Chicken Chess: Chicken Chess is a combination of Benedict Chess and Suicide Chess. As in Suicide, the object is to lose all of your pieces and captures are mandatory. As in Benedict, if you threaten a piece it changes to your color.
• Circe chess: captured pieces are reborn on their starting squares.
• Crazyhouse: captured pieces change the colour and can be dropped on any unoccupied location. There are two variations of this chess variant, known as Loop chess and chessgi.
• Einstein chess: pieces transform into more or less powerful pieces when they move.^[12]
• Extinction chess: A player must capture all of any one type of pieces his/her opponent controls to win (for example, all the knights an opponent has, or all their pawns, etc.)
• Genesis Chess: The game begins with a blank board and opponents take turns placing down or moving pieces.
• Friendly Fire chess: A player can capture not only his/her opponent's pieces but also his/her own instead. Still, the King can't be checked by his own chessmen, though it has a right to capture its chessmen, for example, the King may capture a Rook (which has made castling with it) while it is checked and the Rook is not threatened.^[13]
• Ghost chess: variation in which the black Queen (Ghost), faces the white ranks (Paradigm), and each side has a variety of special moves.
• Guard chess (or Icelandic chess): allows captures only when a piece is completely unprotected by friendly pieces. Checkmate occurs when the piece forcing the mate is protected and therefore cannot be captured.^[14]
• Hierarchical chess: pieces must be moved in the following order: pawn, knight, bishop, rook, queen, king. A player who has the corresponding piece but cannot move it loses the game.^[15]
• Jedi Knight chess: Knights may move three spaces diagonally or horizontally or both, depending on the rules accepted.^[16]
• Kamikaze Chess similar to Suicide Chess. Players must try to lose all their pieces and lose their King last. They must take at every opportunity and make a choice if more than one piece can be taken. Players must not move into check until they only have the King left. If an opponent's move puts them in check, they must get out of it, as per standard chess. If they are checkmated before all the other pieces are gone, they lose. Pawns may only be promoted to a Queen.
• Knight relay chess: pieces defended by a friendly knight can move as a knight.

• Knightmate (also called Mate The Knight) is a game invented by Bruce Zimov in 1972. The goal of the game is to checkmate the opponents's knight (which is placed on e-file). The kings on b- and g- files can be captured as other pieces. Pawns can additionally promote to kings but not to knights.^[17]
• Legan chess: played as if the board would be rotated 45°, initial position and pawn movements are adjusted accordingly.
• Madrasi chess: a piece which is attacked by the same type of piece of the opposite colour is paralysed.
• Monochromatic chess: all pieces must stay on the same colour square as they initially begin.
• Patrol chess: captures and checks are only possible if the capturing or checking piece is guarded by a friendly piece.
• PlunderChess: the capturing piece is allowed to temporarily take the moving abilities of the piece taken.
• Refusal chess (also called Outlaw chess or Rejection chess): when a player makes a move the opponent can refuse to accept it, forcing the first player to change to another move, which must be accepted. The only exception is when only one legal move is possible.^[18]
• Replacement chess: captured pieces are not removed from the board but moved by the capturer anywhere else on the board.^[19]
• Rifle chess (also known as Shooting chess or Sniper chess): When one piece captures another, it remains unmoved in its original square, instead of occupying the square of the piece it has captured.^[20]
• Suicide chess (also known as Giveaway chess, Take Me chess, Loser's chess, Antichess, Must Kill, Reverse Chess): capturing moves are mandatory and the object is to lose all pieces. There is no check - the king is captured like an ordinary piece.
• Three checks chess: you win if you check your opponent three times.
• Transformer chess: Players may swap out pieces for those on the sideline before moving, which are in turn swapped back into play.

[edit] Chess with incomplete information or elements of chance

In these chess variants, luck or randomness sometimes plays a role. Still, like in poker or backgammon, good luck and bad luck even out over the long-term with clever strategy and consideration of probabilities being decisively important.

• ChessHeads: played with cards that change the game rules.^[21][22]
• Chiss: Played with a pack of cards; if a red card is drawn, the pieces have special moves.
• Dark chess: you see only squares of the board that are attacked by your pieces.
• Dice chess: the pieces a player is able to move are determined by rolling a pair of dice.
• Fantasy Chess: Traditional chess with a layer of wargaming added. Players fight for the square (which can be co-occupied) using dice. Can be expanded to 4 player game and piece capability can improve each game. ^[23]
• Knightmare Chess: played with cards that change the game rules.
• Kriegspiel: neither player knows where the opponent's pieces are but can deduce them with information from a referee.
• No Stress Chess: marketed for teaching beginners, the piece or pieces a player is able to move are determined by drawing from a deck of cards, with each card providing the rules for how the piece may move.^[24] Castling and en passant are not allowed.
• Play It By Trust, devised by Yoko Ono. Both players' pieces are white, which means after a few moves, players must learn to trust each other as to whose pieces are whose.
• Penultima: an inductive chess variant where the players must deduce hidden rules invented by "Spectators".
• Schrödinger's chess: each player's minor pieces are concealed in such a way that the opponent does not know what they are until they are revealed. When covered, pieces move in a restricted way.^[25]
• Synchronous chess: players try to outguess each other, moving simultaneously after privately recording intended moves and anticipated results. Incompatible moves, for instance to the same square with no anticipated capture, are replayed. Alternatively, two pieces moving to the same square are both captured, unless one is the king, in which case it captures the other. Play ends with capture of king.^[26]

[edit] Multimove variants

In these variants one or both players can move more than once per turn. The board and the pieces in these variants are the same as in standard chess.

• Avalanche chess: each move consists of a standard chess move followed by a move of one of the opponent's pawns.
• Doublemove chess:^[27] Similar to Marseillais chess, but with no en passant, check, or checkmate; the object is to capture the king.
• Kung-Fu chess: a chess variant without turns. Any player can move any of his pieces at any given moment.
• Marseillais chess or Two-move chess: after the first turn of the game by white being a single move, each player moves twice per turn.
• Monster chess (Also known as Super King): white has the king and four pawns against the entire black army but may make two successive moves per turn.
• Progressive chess: (also known as Scottish chess) the white player moves once, the black player moves twice, the white player moves three times, etc.
• Zonal chess:^[28] board has triangular wings or "zones" on either side of the main 8x8 board. Queens, bishops, and rooks that start from one of the squares in either zone may change direction and keep going on the same move. A queen, for example, could zig around an obstruction and attack a piece in the opposite zone. Note that the power to change direction only applies when a piece's move starts from a zonal area. It is possible (using the queen and rook) to cross the board from one zone to another, but any piece entering a zone cannot make use of the extended move.

[edit] Multiplayer variants

These variants arose out of the desire to play chess with more than just one other person.

• Bosworth: A four player chess variant played on 6x6 board. It uses a special card system with the pieces for spawning.
• Bughouse chess: (also known as Double chess, Exchange chess, Siamese chess, Swap chess, Tandem chess, Matrix chess) two teams of two players face each other on two boards. Allies use opposite colours and give captured pieces to their partner. The two-player version of the game, played with only one board, is Crazyhouse.
• Djambi: can be played by four people with a 9x9 board and four sets of special pieces. The pieces can capture or move the pieces of an adversary. Captured pieces are not removed from the board, but turned upside down. There are variants for three players or five players (Pentachiavel).
• Enochian chess: a four-player variant with magical symbolism, associated with the Hermetic Order of the Golden Dawn.
• Forchess: a four-person version using the standard board and two sets of standard pieces.
• Four-handed chess: (also known as chess 4 and 4-Way chess) can be played by four people and uses a special board and four sets of differently coloured pieces.
• Fortress chess: a four-player variant played in Russia in 18th and 19th centuries.
• Three-handed chess: family of chess variants specially designed for three players.

[edit] Chess with unusual pieces

Most of the pieces in these chess variants are borrowed from chess. The game goal and rules are also very similar to those in chess. However, these chess variants include one or more fairy pieces which move differently than chess pieces.

• Anti-king chess: uses an anti-king. This piece is in check when not attacked. If the player has an anti-king in check and unable to move it to the position attacked by the opponent, the player loses (checkmate). The anti-king cannot capture opponent's pieces, but it can capture friendly pieces. The king does not attack the anti-king of the opponent. The anti-king does not check its own king. All other rules are the same as in standard chess, including check and checkmate to usual king. The game was invented by Peter Aronson in 2002.^[29]
• Baroque: (also known as Ultima) pieces on the first row move like queens, and pieces on the second row move like rooks. They are named after their unusual capturing methods. For example, Leaper, Immobilizer, and Coordinator.
• Berolina chess: Which uses the Berolina Pawn instead of the normal pawn, all other things being equal.
• Bomberman chess: Inspired by the Bomberman video game series. Played on an 10x8 board with special Bomb and Defuser pieces. The Bomb piece can be exploded on its turn in vertical and horizontal directions (similar to the movement of a rook), destroying any pieces in the blast range, and the Defuser piece can capture a bomb piece.^[30]
• Chess with different armies: two sides use different sets of fairy pieces. There are several armies of approximately equal strength to choose from including the standard FIDE chess army.
• Dragon chess: uses three 8×12 boards atop one another, with new types of chess pieces.
• Duell: dice are used instead of pieces.
• Gess: chess with variable pieces, played on a go-board.
• Grasshopper chess: is a chess variant in which the pawns can promote to grasshopper, or in which grasshoppers are on the board in the opening position.
• Maharajah and the Sepoys: black has a complete army, white only one piece - Maharajah (Queen + Knight).
• Omega chess: played on a 10×10 board with four extra squares, one per corner. Also, two fairy chess pieces are used, the Champion and the Wizard. Both can jump other pieces like the Knight.
• Pocket mutation chess: player can put a piece temporary into the pocket, optionally mutating it into another piece.
• Pole chess: each player has an uncapturable piece known as a Pole. The Pole, which does not begin play on the board, may be moved to any empty space on the board as a legal move. Thus, the Pole can be used to block check, making it much harder to achieve mate. Mentioned in the novel Blue Adept by Piers Anthony.
• Reflecting Bishops: a Bishop is allowed to "bounce" off the edge of the board when making a move, similar to a hockey puck or billiard ball. Its path continues down the diagonal to any legitimate square after the "bounce".
• Stealth chess: played in the fictional Ankh-Morpork Assassins' Guild from the Discworld series of books; played on an 8×10 board. The fairy piece is the Assassin.
• Shako (Chess): played on a 10×10 board. New pieces are the Cannon from Xiangqi(Chinese Chess) and an Elephant moving as Fers+Alfil of old Shatranj (ancestors of Queen and Bishop), so diagonally one or two squares with jumps allowed.

[edit] Bishop+knight and rook+knight compounds

There are a numbers of chess variants which use bishop+knight and rook+knight compound pieces. Several different names have been given to these pieces. Rook and knight compound (R+N) is named chancellor, marshall, empress etc.^[31] Bishop and knight compound piece (B+N) is called archbishop, cardinal, janus, paladin, princess, Prime Minister etc.^[32] To adapt two new pieces the board is usually extended to 10x8 or 10x10 with two additional pawns added.

• Capablanca chess: a chess variant by the former world chess champion, José Raúl Capablanca. Played on a 10×8 board with chancellor (R+N) and archbishop (B+N).
• Capablanca random chess: by Reinhard Scharnagl (2004). A generalization of all possible variants of Capablanca chess with random starting positions following a method similar to that used in Chess960.
• Embassy Chess: by Kevin Hill (2005). Played on a 10×8 board with marshall (R+N) and cardinal (B+N). The starting position is taken from Grand chess.
• Gothic chess: a commercial chess variant. Played on a 10×8 board with chancellor (R+N) and archbishop (B+N).
• Grand chess: by Christian Freeling (1984). Played on a 10×10 board with marshall (R+N) and cardinal (B+N).
• Janus chess by Werner Schöndorf (1978). Played on 10×8 board with two januses (B+N).
• Modern chess: played on a 9x9 board, with an extra pawn and a Prime Minister (Bishop + Knight). It was created by Puerto Rico's Gabriel Vicente Maura in 1968.
• Seirawan chess: invented by grandmaster Yasser Seirawan in 2007. Played on standard 8x8 board with elephant (R+N) and hawk (B+N).

[edit] Games inspired by chess

These chess variants are very different from chess and may be classified as abstract board games instead of chess variants (by restrictive, proper definition).

• Arimaa: A game inspired by Garry Kasparov's defeat by chess computer Deep Blue. This game is easy for people to understand but difficult for computers to play well.
• ChessWar: complex strategy game played with chess pieces and board.^[33]
• Navia Dratp:a cross between chess and miniature wargaming.
• Martian chess: played with Icehouse pieces.
• Shuuro: a cross between chess and miniature wargaming.
• DracoKrak Chess: fully customizable fantasy board game with elements of Chess, miniature wargame, role-playing game.

[edit] Chess-related historic and regional games

Some of these games have developed independently while others are ancestors or relatives of modern chess.^[34]

The popularity of these chess variants may be limited to their respective places of origin (as is largely the case for shogi), or worldwide, as is the case for xiangqi which is played by overseas Chinese everywhere. These games have their own institutions and traditions.

[edit] Historic chess-related games

• Chaturanga - an ancient Indian game, presumed to be the common ancestor of chess and other national chess-related games.
• Chaturaji - four handed version of Chaturanga, played with a die.
• Shatranj - an ancient Persian game, derived from Chaturanga.
• Tamerlane chess - a significantly expanded variation of Shatranj.
• Short assize - played in England and Paris in the second half of the 12th century.
• Courier chess - played in Europe from 15th to 19th century. Probably was one step in evolving modern chess out of Shatranj.

[edit] Regional chess-related games

• Xiangqi - China.
• Jungle (or animal chess) - China.
• Banqi (or Chinese Half chess) - China.
• Chandraki - Tibet.
• Shogi - Japan (see also shogi variants).
• Shatar - Mongolia.
• Hiashatar - Mongolia
• Janggi - Korea.
• Main Chator - Malaysia, Indonesia, Philippines.
• Makruk - Thailand.
• Samantsy - Madagascar
• Senterej - Ethiopia
• Sittuyin - Burma.
• Ouk Chatrang - Cambodia
• Rek Chess - Cambodia

[edit] Chess variants software

Some program authors have created stand-alone applications that are capable of playing a few, many or an unlimited number of variants.

• Zillions of Games - supports an unlimited number (but not types) of chess variants. One can write his/her own rule files to create and play almost all chess variants, as well as almost any abstract strategy board game.
• ChessV - supports around 50 chess variants, including such popular variants as Grand chess, Shatranj, Three Checks chess, Ultima.
• SMIRF - supports all FRC variants upon the 8x8 board and all CRC variants upon the 10x8 board.
• Sunsetter - Normal Chess, Crazyhouse and Bughouse chess engine (opensource).
• Sjeng - besides Crazyhouse and Bughouse chess, supports other chess variants.
• Mini Chess - supports 6x5 board variants of chess, makruk, and shatranj.
• DoubleChessBoard - supports bughouse, coin, ingols chess variants and various alternative starting positions.

[edit] Notes

[edit] References

• Pritchard, D. (2007). The Classified Encyclopedia of Chess Variants. John Beasley. ISBN 978-0955516801. 

[edit] See also

Wikipedia:Books has a book on: Chess variants

• Advanced chess, Centaur chess or Cyborg chess
• Blitz chess
• Fairy chess
• Fairy chess pieces
• Chess boxing
• Chess as mental training
• List of abstract strategy games

[edit] External links

[edit] General

• The Chess Variant Pages
• The Chess Variants wiki
• British Chess Variant Society
• Variant Chess Games
• Variety and history of Chess in ancient world
• The Chess Family - History and Useful Information
• Variant chess database - contains games for atomic chess, suicide chess, losers chess and "wild" variants.
• Chess Variant Applets that can play each variant

[edit] Collections

In addition to individual chess variants with popularity, collections (generally acknowledged to be of respectable quality) have been created by several inventors:

• Zillions Chess Variants Karl Scherer
• Games Gallery Fergus Duniho
• Board Game Page Peter Aronson
• Chess Variants João Pedro Neto
• Chess Variants (Zillions) Mats Winther
• Chess Variants Jean-Louis Cazaux

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