Chess960, also known as Fischer Random Chess, is a chess variant that randomizes the starting position of the pieces on the back rank. It was introduced by former world chess champion Bobby Fischer in 1996 to reduce the emphasis on opening preparation and to encourage creativity in play. Chess960 uses the same board and pieces as classical chess, but the starting position of the pieces on the players' is randomized, following certain rules. The random setup makes gaining an advantage through the memorization of openings unfeasible. Players instead must rely on their skill and creativity.
Randomizing the main pieces had long been known as shuffle chess, but Fischer introduced new rules for the initial random setup, "preserving the dynamic nature of the game by retaining for each player and the right to castle for both sides".Gligorić (2002), p. 40. The result is 960 distinct possible starting positions.
In 2008, FIDE added Chess960 to an appendix of the Laws of Chess. The first world championship officially sanctioned by FIDE, the FIDE World Fischer Random Chess Championship 2019, brought additional prominence to the variant. It was won by Wesley So. In 2022, Hikaru Nakamura won the second edition. In 2026, Magnus Carlsen became the new champion.
Rules Setup Before the game, a starting position is randomly determined and set up, subject to certain requirements. White's pieces (not pawns) are placed randomly on the first , following two rules: The bishops must be placed on opposite-color squares. The king must be placed on a square between the rooks.
There are 960 possible starting positions.There are 4 light squares for one bishop, 4 dark squares for the other bishop, 6 remaining squares for the queen, and ways to place the two (identical) knights on the remaining 5 squares, giving possible starting positions. After these pieces are placed, there is only one way to place two rooks and king on the remaining 3 squares, since the king must be between the rooks. The starting position is usually chosen randomly by software, but can be done using multiple rolls of a standard six-sided die.
Black's pieces are placed equal-and-opposite to White's pieces. (For example, if the white king is randomly determined to start on f1, then the black king is placed on f8.) Pawns are placed on the players' second ranks as in classical chess.
After setup, the game is played the same as classical chess in all respects, with the exception of castling from the different possible starting positions for king and rooks.
Castling rules As in classical chess, each player may castle once per game, moving both the king and a rook in a single move; however, the castling rules were reinterpreted in Chess960 to support the different possible initial positions of king and rook. After castling, the final positions of king and rook are the same as in classical chess, namely:
+ Examples of castling
After a-side castling (/long castling in classical chess), the king finishes on the c- and the a-side rook finishes on the d-file. The move is notated 0-0-0 as in classical chess. After h-side castling (/short castling in classical chess), the king finishes on the g-file and the h-side rook finishes on the f-file. The move is notated 0-0 as in classical chess.
Castling prerequisites are the same as in classical chess, with some minor clarifications: In standard chess, the king and the castling rook must not have previously moved. In Chess960, it is also specified that a player may only castle once in a game, because in some configurations it is possible to castle without moving the king. The player must not castle out of check or through check. This means that no square from the king's initial square to its final square may be under attack by an enemy piece, even if the king is already on its final square. There is no such restriction on the rook. The rook may move from, through or onto a threatened square, provided that no other restriction prevents this. All the squares between the king's initial and final squares (including the final square), and all the squares between the castling rook's initial and final squares (including the final square), must be vacant except for the king and castling rook.
FIDE's recommended procedure for castling unambiguously is first to move the king outside the playing area next to its final square, then to move the rook to its final square, then to move the king to its final square. Another recommendation is to verbally announce the intent to castle before doing so.
History
Van Zuylen van Nijevelt's early contributions The concept of random chess, also known as shuffle chess, was first proposed by the Dutch chess enthusiast Philip Julius van Zuylen van Nijevelt (1743–1826). In his renowned treatise on chess, La Supériorité aux Échecs, published in 1792, Van Zuylen van Nijevelt articulated his disdain for the repetitive patterns often found in standard chess openings. He proposed the idea of randomizing the starting positions of the main pieces to create a vast array of distinct situations, eliminating the possibility of pre-game memorization or extensive opening theory. Van Zuylen van Nijevelt's book, with its full title La Supériorité aux Échecs mise à la portée de tout le monde, et particulièrement des dames qui aiment cet amusement ("Superiority in Chess brought into the reach of all, and particularly of ladies who love that amusement/as passtime"), gained significant popularity and was reprinted several times. Its influence extended beyond the French-speaking world of that time, as it was subsequently translated into multiple languages, spreading the idea of randomizing the initial positions of chess pieces to a wider audience. This early conception of random chess by Van Zuylen van Nijevelt laid the foundation for Chess960.
Van Zuylen van Nijevelt's innovative approach to chess not only offered a solution to the repetitive nature of traditional openings but also paved the way for the exploration of chess variants that deviate from the conventional starting position. His quote within La Supériorité aux Échecs emphasizes the core principle behind random chess, stating, "This produces a huge number of different situations, so that no one can study them beforehand," reflecting his desire to introduce an element of unpredictability and originality into the game of chess. The legacy of Van Zuylen van Nijevelt's contributions to the evolution of chess remains significant, with his early insights serving as a cornerstone for the development of various randomized chess variants, including Chess960.Gligorić (2002), p. 36.La Régence: journal des échecs, Volume 3, La partie aux pièces déplacées (year 1851 page 299-301)
Development and further evolution The pioneering work of Van Zuylen van Nijevelt found continued development through the efforts of his nephew, the Jonkheer Elias van der Hoeven (1778–1854), a Dutch diplomat. Van der Hoeven took the concept of shuffle chess further, potentially sharing his insights with Aaron Alexandre, evident from Alexandre's incorporation of the theory into his Encyclopédie des échecs in 1837.
The earliest documented games of shuffle chess were played between Van der Hoeven and Alexandre in Mannheim in 1842, with Alexandre emerging victorious with a score of 3–0. One of these games is preserved in Sissa, the Netherlands' first long-standing chess journal, demonstrating an initial position with two advanced pawns on each side. A later game played by Van der Hoeven was against Baron von der Lasa (1818–1899), adhering more closely to the contemporary rules of random chess, except for the monochromatic bishop pairs.
In 1851, Van der Hoeven visited Willem Verbeek, the editor-in-chief of Sissa. Verbeek and Hancock, Verbeek's chess companion in Amsterdam during the 1850s, delved into shuffle chess, with their initial findings documented in the pages of the Sissa journal.
Van der Hoeven's modifications to the original concept of random chess were published in Alexandre's Encyclopédie in 1837 and later republished in Sissa by an individual known as T. Scheidius. This variant began to be referred to as "schaakspel, naar de wijze van jhr. Van der Hoeven" or "schaakspel à la Van der Hoeven."
Following Van der Hoeven's visit, the Sissa Chess Society received an invitation from the Philidor Chess Society in Amsterdam, in collaboration with Van der Hoeven, to organize a shuffle chess tournament. The aim was to promote the dissemination and popularity of the chess variant attributed to Van der Hoeven. Originally intended as a tournament among the eight prize winners of the 1851 Philidor-organized event, logistical challenges led to invitations being extended to other chess societies. Ultimately, a tournament with seven players from Amsterdam, along with the 74-year-old Van der Hoeven, was organized. Notable participants included Maarten van 't Kruijs (Philidor), J. Seligmann (Philidor), H. Kloos (La Bourdonnais), M.M. Coopman, and F.G. Hijmans / S. Heijmans, supplemented by Mohr and J. van Praag. Van ’t Kruijs emerged as the winner of the tournament, reinforcing the growing sentiment that the removal of opening theory allows true chess talent to shine.
Fischer's influence and popularization Fischer's modification "imposes certain restrictions, arguably an improvement on the anarchy of the fully randomized game in which one player is almost certain to start at an advantage".Pritchard (2000), p. 18. Fischer started to develop his new version of chess after the 1992 return match with Boris Spassky. The result was the formulation of the rules of Fischer Random Chess in September 1993, introduced formally to the public under the name "Fischerandom Chess", on June 19, 1996, in Buenos Aires, Argentina."It was the world chess champion Robert James Fischer who, in 1996, formulated precise rules for randomized chess ... . Though still not so well-known, this invention of Bobby Fischer is already raising reasonable hopes among experts that chess will remain a mass game for the foreseeable future." . "Despite his extremely long absence from competition, he [Fischer] won it [the 1992 return match with Spassky] with a good score of 10–5 in decisive games. It was then that Fischer began to think of reforming the game. The result of his hard work over several years is Fischerandom Chess—and plans for exhibition matches of a new kind..." .The Week in Chess 88, The Week in Chess, 24 June 1996
Fischer's goal was to eliminate what he considered the complete dominance of opening preparation in classical chess, replacing it with creativity and talent. In a situation where the starting position was random it would be impossible to fix every move of the game. Since the "opening book" for 960 possible opening systems would be too difficult to devote to memory, the players must create every move originally. From the first move, both players must devise original strategies and cannot use well-established patterns."In Fischerandom Chess the normal patterns that a grandmaster has been trained to recognise are missing." —Matthias Wuellenweber ; "I cannot use my vast experience to reach middlegame positions where I already know the typical plans." —Artur Yusupov ."Preparation is practically impossible and players will give it up as a bad job. Devotees of fianchettoes will seldom obtain their favourite opening position. A competitor's preference for the king or queen's pawn opening has to be put aside and he must, like a born again chessplayer, orient himself without established opening knowledge." —Gligorić Fischer believed that eliminating memorized book moves would level the playing field.