A chess variant
is a game
derived from, related to or similar to chess
in at least one respect. 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, confining the number to published ones. In 1998 Zillions of Games software program was created. It enables non-programmers to design and playtest most types of chess variants using an AI opponent. As a result a large number of chess variants were implemented for Zillions of Games.
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.
These chess variants are derived from chess
by changing the board, pieces or rules.
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.
- D-chess: similar to Transcendental Chess, but only one game is needed to be played against each opponent as the unequal starting positions are equalized with the weaker side having the option to transpose two pieces and then gets to move first.
- Upside-down chess. The black and white pawns are switched so that all the pawns are one step away from capturing an opponent piece and getting promoted. The game can start, for example: 1. Nc6 Nf3 2. b8Q g1Q etc.
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.
- 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). An alternate setup is that the knight next to the king is taken.
- 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.
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.
- 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.
- 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.
- 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 infinite symbol. It is connected at the center, and all pieces of the traditional chess are used.
- 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.
- 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.
Chess with unusual rules
These chess variants have the same pieces and board as chess but some rules for moving, capturing, etc are changed. The game goal can be also different from that in chess.
- 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 8 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.
- Bughouse chess: Similar to Crazyhouse; has four people and two boards; captured pieces can be dropped by a player's teammate
- 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.
- Extinction chess: A player must capture all of his/her opponent's pieces to win.
- Genesis Chess: The game begins with a blank board and opponents take turns placing down or moving pieces.
- Gentlemen's Chess (or No Trading Chess): pieces can only be captured when completely unprotected. To avoid crowding on the board, pawns can move in all eight directions as long as they only capture in the normal fashion.
- 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.
- Ghost Chess: variation in which the black Queen (Ghost), faces the white ranks (Paradigm), and each side has a variety of special moves.
- 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.
- 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.
- 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.
- Replacement chess: captured pieces are not removed from the board but moved by the capturer anywhere else on the board.
- 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.
- Suicide chess (also known as Giveaway chess, Take Me chess, Loser's chess, Antichess, Must Kill): 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.
- Jedi Knight chess: Knights may move three spaces diagonally or horizontally or both, depending in the rules accepted.
Chess with incomplete information and/or elements of chance
In these chess variants, luck or randomness sometimes plays a role. Still, like in poker
, good luck and bad luck even out over the long-term with clever strategy and consideration of probabilities being decisively important.
- 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.
- 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. Castling and en passant are not allowed.
- 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.
- 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.
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
- 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.
- Doublemove chess: Similar to Marseillais chess, but with no en passant, check, or checkmate; the object is to capture the king.
- Progressive chess: (also known as Scottish chess) the white player moves once, the black player moves twice, the white player moves three times, etc.
- Avalanche chess: each move consists of a standard chess move followed by a move of one of the opponent's pawns.
- Kung-Fu chess: a chess variant without turns. Any player can move any of his pieces at any given moment.
- 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.
- Zonal chess: 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.
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) two teams of two players face each other on two boards. Allies use opposite colours and give captured pieces to their partner. The 2-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.
- Three-handed chess: family of chess variants specially designed for three players.
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.
- 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.
- 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.
- 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. It's 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.
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
etc. Bishop and knight compound piece (B+N) is called archibishop
, Prime Minister
etc. To adapt two new pieces the board is usually extended to 10x8 or 10x10 with two additional pawns added.
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).
Chess-related national games
Some of these games have developed independently while others are ancestors or relatives of modern chess. Nonetheless, they are potentially definable as chess variants (with some possible difficulties). 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.
Chess variants software
Some program authors have created stand-alone applications that are capable of playing one, many or an unlimited number of variants.
- Pritchard, D. (2007). The Classified Encyclopedia of Chess Variants. John Beasley. ISBN 978-0955516801.
In addition to individual chess variants with popularity, collections (generally acknowledged to be of respectable quality) have been created by several inventors:
Internet servers to play chess variants