Editing List of chess variants (section)

=== Variant starting position (rectangular board, standard piece types and rules) ===
Many variants employ standard chess rules and mechanics, but vary the number of pieces, or their starting positions. In most such variants, the pawns are placed on their usual squares, but the position of other pieces is either randomly determined or selected by the players. The motivation for these variants is usually to nullify established [[chess opening|opening]] knowledge. The downside of these variants is that the initial position usually has less harmony and balance than the standard chess position.{{sfnp|Pritchard|2000|p=18}}
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 |'''Upside-down chess''' starting position (White sits at bottom)
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==== Fixed positions ====
* '''Active chess''': Played on a 9×8 board, adding a queen with an extra pawn in front. Invented by G. Kuzmichov (1989), whose students tested the game, deciding that the optimal starting position was to place the second queen on the eighth or ninth files.{{sfnp|Pritchard|2007|p=114}}
* '''[[Displacement chess]]''' [multivariant]: 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 knight on the b-[[file (chess)|file]] is traded with the bishop on the f-file.
[{{#invoke:Chessboard mxn|board|cols=16|rows=12
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|'''[[Double Chess]]''' by Julian Hayward}}
* '''[[Double chess]]''': Two full armies per side on a 12×16 board, the first to mate an enemy king wins. Pawns advance up to four steps on their first move. [[José Raúl Capablanca|Capablanca]] found the game "remarkably interesting".{{sfnp|Pritchard|1994|p=91|ps=: "Hayward drew Capablanca's attention to the game. The Cuban found it 'remarkably interesting' and a match was arranged between him and the Hungarian master Geza Maroczy."}} Invented by Julian Hayward (1916).
* '''Endgame chess''' (or '''the Pawns Game''', with unknown origins): Players start the game with only pawns and a king. Normal check, checkmate, ''[[en passant]]'', and pawn promotion rules apply.{{sfnp|Pritchard|2007|p=72}}
* '''[[Los Alamos chess]]''' (or '''anti-clerical chess'''): Played on a 6×6 board without bishops. This was the first chess-like game played by a computer program.
* '''Upside-down chess''': The white and black pieces are switched so that White's pieces are on the 8th rank, with pawns on the 7th rank, one step away from promotion. The starting position looks like a standard chess starting position, but from the other player's perspective. As the pawns are blocked by pieces in the starting position, the game always starts with a knight move, and [[smothered mate]]s are common.<ref>[http://www.chessvariants.org/diffsetup.dir/upside.html Upside-down chess] {{Webarchive|url=https://web.archive.org/web/20060618023432/http://www.chessvariants.org/diffsetup.dir/upside.html |date=2006-06-18 }} by [[Hans Bodlaender]]</ref>

==== Player-chosen positions ====
* '''Casablanca chess''': The starting position is chosen from a famous historic game; usually an interesting [[Chess middlegame|middlegame]] position. The position is verified to be approximately equal by a computer, and should have winning chances for both sides.<ref>{{cite web |url=https://www.mcw.ma/_files/ugd/78af52_eae053e1b06c453cb43fb1d00a7f045a.pdf |title=Casablanca variant for website |access-date=20 May 2024 |archive-date=20 May 2024 |archive-url=https://web.archive.org/web/20240520223547/https://www.mcw.ma/_files/ugd/78af52_eae053e1b06c453cb43fb1d00a7f045a.pdf |url-status=live }}</ref> The first Casablanca chess tournament was played in May 2024, and won by [[Magnus Carlsen]].<ref>{{cite web |title=The Tournament |url=https://www.mcw.ma/en/le-tournoi |website=Casablanca-Chess |access-date=20 May 2024 |language=en |archive-date=20 May 2024 |archive-url=https://web.archive.org/web/20240520223546/https://www.mcw.ma/en/le-tournoi |url-status=live }}</ref><ref>{{cite web |last1=Lang |first1=J. J. |title=Learning From the Classics: Takeaways from First Casablanca Variant Tournament in Morocco |url=https://new.uschess.org/news/learning-classics-takeaways-first-casablanca-variant-tournament-morocco |website=US Chess.org |access-date=20 May 2024 |language=en |date=20 May 2024 |archive-date=20 May 2024 |archive-url=https://web.archive.org/web/20240520222203/https://new.uschess.org/news/learning-classics-takeaways-first-casablanca-variant-tournament-morocco |url-status=live }}</ref>
* '''Pre-chess''': The game starts with white and black pawns set as usual, but the initial position of other pieces is selected by the players. White first places one of their pieces on their first rank, and then Black does the same. Players continue to alternate in this manner until all pieces have been placed, with the only restriction being that bishops must be on opposite-colour squares. The game then proceeds in the usual way. Proposed by [[Pal Benko]] in 1978.{{sfnp|Pritchard|2007|p=77}}
* '''Polgar reform chess''' [multivariant]: In his book ''Reform-Chess'' (1997), [[László Polgár]] proposed several variants played on board of size 5×8, 6×8, 8×6, or 9×6.<ref>{{cite book |author=László Polgár |title=Reform-Chess |publisher=Könemann Verlags GmbH |year=1997 |isbn=978-3-89508-226-9|author-link=László Polgár }}</ref> The initial piece setup is determined by players in the same way as in Benko's Pre-chess. There are special rules for [[castling]] depending on the board. Polgár recommended these variants to train creativity and to speed up the game.

==== Random positions ====
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 |'''[[Chess960]]''', one of the 960 possible starting positions
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* '''[[Fischer Random Chess]]''' (also known as '''Chess960''' and more recently as '''Freestyle Chess'''): The placement of the pieces on the first [[rank (chess)|rank]] is randomized; although there are rules such as the 2 starting Bishops have to be on different colour squares, and the King has to start between the 2 Rooks. The opponent's pieces mirror it. Invented by [[Bobby Fischer]] (1996).
* '''[[Transcendental Chess]]''': Similar to [[Chess960]], but the opening white and black positions do not mirror each other.

==== Unequal armies ====
In these variants, White and Black do not necessarily begin with the same quantities of each piece type (for example, White may begin with more pawns than Black).
* '''[[Dunsany's Chess]]''' (and the similar '''Horde chess'''): One side has standard chess pieces, and the other side has 32 pawns.
* '''[[Chess handicap|Handicap chess]]''' (or '''Chess with odds''') [multivariant]: Variations to equalise chances of players with different strength.
* '''Peasants' Revolt''': White has a king and eight pawns (the peasants) against Black's king, pawn, and four knights (the nobles). Black has the advantage. To narrow the contest, the game has also been played with three knights (on b8, c8, and g8) instead of four. By R. L. Frey (1947).<ref>{{cite web |url=http://www.chessvariants.org/large.dir/peasantrevolt.html |title=Peasant Revolt |last=Whelan |first=George |publisher=[[The Chess Variant Pages]] |date=2003-03-10 |access-date=2014-01-21 |archive-date=2014-02-04 |archive-url=https://web.archive.org/web/20140204041855/http://www.chessvariants.org/large.dir/peasantrevolt.html |url-status=live }}</ref>{{sfnp|Pritchard|2007|p=76}}
* '''Sixteen Pawns''': White plays without their queen, but chooses where on the third and fourth ranks to place eight extra pawns. By [[Legall de Kermeur]] (18th century). [[Alexandre Deschapelles]] and [[Louis-Charles Mahé de La Bourdonnais]] later established that eight extra pawns favour White too much, and hence played the game with only five, six, or seven extra pawns for White instead.<ref>{{cite web | url=http://www.chessvariants.com/unequal.dir/16pawns.html | title=Sixteen Pawns | access-date=2017-12-22 | archive-date=2017-12-22 | archive-url=https://web.archive.org/web/20171222105938/http://www.chessvariants.com/unequal.dir/16pawns.html | url-status=live }}</ref>
* '''[[Really Bad Chess]]''': A [[mobile video game]] by [[Zach Gage]]; Each player has one king and fifteen other pieces selected at random. 
* '''Weak!''': White has the usual pieces, Black has one king, seven knights, and sixteen pawns. This game was played at a Columbia University chess club in the 1960s.<ref>[http://www.chessvariants.org/unequal.dir/weak.html Weak!] {{Webarchive|url=https://web.archive.org/web/20060307011958/http://www.chessvariants.org/unequal.dir/weak.html |date=2006-03-07 }} by [[Hans Bodlaender]]</ref>

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 |'''Peasants' Revolt''' by R. L. Frey
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 |'''Really Bad Chess''' (example) by Zach Gage
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 |'''Weak!''' by [[Ralph Betza]]
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