Welcome to the Four-Player Chess Wikibook! This book is about modern four-player chess and specifically the main variants Teams and Free-For-All (FFA) with the standardised rules as found on the internet chess server Chess.com. 
The exact origins of the modern single-board four-player chess game, using a board with extensions on each side, are unclear. However, the earliest account of a four-player chess-like game comes from the book Tahqiq ma li-l-hind, a study on Indian culture written by the Persian scholar Al-Biruni around the year 1030.  The book mentions a four-handed variant of the ancient Indian strategy game Chaturanga, played on a standard 8x8 board. This four-handed version of Chaturanga is also known as Chaturaji (Sanskrit for "four kings"). The game could be played in partnership or all-against-all and it originally involved dice to determine which piece to move.  Chaturaji was once believed to be the ancestor of modern two-player chess according to the debunked Cox–Forbes theory, but is now commonly believed to have evolved as a variant from the two-handed game Chaturanga, dated 400 years earlier. 
The modern four-player chess game is often credited to George Hope Verney, who first documented it in a booklet in 1881 , although probably many four-player chess variants existed prior to that.  His version of the game used a board extended by three rows on each side and four complete sets of regular chess pieces. The players opposite to each other were partners and the objective was to checkmate both opponents. When checkmated, a player's pieces would become inert and could not be captured by adversaries, blocking the squares they occupied. The checkmated player's partner would continue the game alone and could release his partner from the checkmate by capturing the pieces holding him in checkmate or forcing them to move. The opponents could also choose to release the checkmated player themselves, if they considered it desirable to do so.  Verney's game became quite popular in and outside London. In 1885 he wrote an extensive book on chess variants  and he even founded a Four-Handed Chess Club, which existed until the second World War.  Many similar variants have appeared since, but as yet there are no official rules and the World Chess Federation FIDE does not recognise four-player chess in any form.
Table of Contents
- How to play?
- Checkmate patterns
- Common openings
- World Championships
When contributing to this Wikibook, please follow the book's Conventions.
- "Four-Player Chess Rules". Chess.com. https://www.chess.com/4-player-chess?t=rules. Retrieved 2019-01-05.
- Jean-Louis Cazaux (2014-11-22). "Four-Handed Chaturanga a.k.a Chaturaji". http://history.chess.free.fr/chaturanga.htm. Retrieved 2019-01-05.
- Pritchard, D.B. (2007). J.D. Beasley. ed. The Classified Encyclopedia of Chess Variants (2nd ed.). J.D. Beasley. pp. 311-312. ISBN 978-0-9555168-0-1. https://www.jsbeasley.co.uk/encyc.htm.
- Verney, George Hope (1881). Four-Handed Chess. London: George Routledge and Sons. https://www.chessvariants.com/books.dir/4handed/index.html.
- "4 Player Chess". BoardGameGeek. https://boardgamegeek.com/boardgame/2173/4-player-chess. Retrieved 2019-01-05.
- Verney, George Hope (1885). Chess Eccentricities. London: Longmans, Green & Co. https://www.chessvariants.com/chess-eccentricities/.
- "Four Handed Chess II". The Chess Variant Pages. https://www.chessvariants.com/multiplayer.dir/fourhanded2.html. Retrieved 2019-01-06.