Castling is a move in
chess
Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to disti ...
. It consists of moving the
king
King is the title given to a male monarch in a variety of contexts. The female equivalent is queen, which title is also given to the consort of a king.
*In the context of prehistory, antiquity and contemporary indigenous peoples, the tit ...
two squares toward a
rook
Rook (''Corvus frugilegus'') is a bird of the corvid family. Rook or rooks may also refer to:
Games
*Rook (chess), a piece in chess
*Rook (card game), a trick-taking card game
Military
* Sukhoi Su-25 or Rook, a close air support aircraft
* USS ...
on the same and then moving the rook to the square that the king passed over. Castling is permitted only if neither the king nor the rook has previously moved; the squares between the king and the rook are vacant; and the king does not leave, cross over, or finish on a square attacked by an enemy piece. Castling is the only move in chess in which two pieces are moved at once.
Castling with the is called ''kingside castling'', and castling with the is called ''queenside castling''. In both
algebraic and
descriptive
In the study of language, description or descriptive linguistics is the work of objectively analyzing and describing how language is actually used (or how it was used in the past) by a speech community. François & Ponsonnet (2013).
All acad ...
notations, castling kingside is written as 0-0 and castling queenside as 0-0-0.
Castling originates from the ''king's leap'', a two-square king move added to European chess between the 14th and 15th centuries, and took on its present form in the 17th century. Local variations in castling rules were common, however, persisting in Italy until the late 19th century. Castling does not exist in Asian games of the chess family, such as
shogi
, also known as Japanese chess, is a strategy board game for two players. It is one of the most popular board games in Japan and is in the same family of games as Western chess, ''chaturanga, Xiangqi'', Indian chess, and '' janggi''. ''Shōgi'' ...
,
xiangqi
''Xiangqi'' (; ), also called Chinese chess or elephant chess, is a strategy board game for two players. It is the most popular board game in China. ''Xiangqi'' is in the same family of games as '' shogi'', '' janggi'', Western chess, '' ch ...
, and
janggi
''Janggi'' (including romanizations ''changgi'' and ''jangki''), sometimes called Korean chess, is a strategy board game popular on the Korean Peninsula. The game was derived from xiangqi (Chinese chess), and is very similar to it, including th ...
, but it commonly appears in
variants
Variant may refer to:
In arts and entertainment
* ''Variant'' (magazine), a former British cultural magazine
* Variant cover, an issue of comic books with varying cover art
* ''Variant'' (novel), a novel by Robison Wells
* " The Variant", 2021 e ...
of Western chess.
Rules
Description
During castling, the king is shifted two squares toward a rook of the same color on the same rank, and the rook is transferred to the square crossed by the king. There are two forms of castling:
* Castling (''short castling'') consists of moving the king to g1 and the rook to f1 for White, or moving the king to g8 and the rook to f8 for Black.
* Castling (''long castling'') consists of moving the king to c1 and the rook to d1 for White, or moving the king to c8 and the rook to d8 for Black.
Requirements
Castling is permitted provided all of the following conditions are met:
# Neither the king nor the rook has previously moved.
# There are no pieces between the king and the rook.
# The king is not currently in
check
Check or cheque, may refer to:
Places
* Check, Virginia
Arts, entertainment, and media
* ''Check'' (film), a 2021 Indian Telugu-language film
* ''The Checks'' (episode), a 1996 TV episode of ''Seinfeld''
Games and sports
* Check (chess), a thr ...
.
# The king does not pass through or finish on a square that is attacked by an enemy piece.
Conditions 3 and 4 can be summarized by the
mnemonic
A mnemonic ( ) device, or memory device, is any learning technique that aids information retention or retrieval (remembering) in the human memory for better understanding.
Mnemonics make use of elaborative encoding, retrieval cues, and imag ...
:
A player may not castle out of, through, or into check.
Castling rules often cause confusion, even occasionally among high-level players.
Alexander Beliavsky
Alexander Genrikhovich Beliavsky (, ua, Олександр Генріхович Бєлявський, sl, Aleksander Henrikovič Beljavski; also romanized ''Belyavsky''; born December 17, 1953) is a Soviet, Ukrainian and Slovenian chess play ...
and
Viktor Korchnoi
Viktor Lvovich Korchnoi ( rus, Ви́ктор Льво́вич Корчно́й, p=vʲiktər lʲvovʲɪtɕ kɐrtɕˈnoj; 23 March 1931 – 6 June 2016) was a Soviet (before 1976) and Swiss (after 1980) chess grandmaster (GM) and chess writer. He ...
both had to consult the arbiter during tournaments on whether castling was legal,
Yuri Averbakh
Yuri Lvovich Averbakh (russian: Ю́рий Льво́вич Аверба́х; 8 February 1922 – 7 May 2022) was a Russian chess grandmaster and author. He was chairman of the USSR Chess Federation from 1973 to 1978. He was the first centenaria ...
once mistakenly thought that Black queenside castling was illegal when b8 was attacked, and
Nigel Short
Nigel David Short (born 1 June 1965) is an English chess grandmaster, columnist, coach, and commentator, who is the vice-president of FIDE since October 2018. Short earned the Grandmaster title at the age of 19, and was ranked third in the w ...
once attempted to castle queenside as Black when d8 was under attack (this was not allowed). Illegal castling has also occasionally occurred in serious games between top players (including
Gata Kamsky
Gata Kamsky ( tt-Cyrl, Гата Камский, italics=no; russian: Гата Камский; born June 2, 1974) is a Soviet-born American chess grandmaster, and a five-time U.S. champion.
Kamsky reached the final of the FIDE World Chess Cham ...
, Viktor Korchnoi, and
Richard Réti
Richard Selig Réti (28 May 1889 – 6 June 1929) was an Austro-Hungarian, later Czechoslovakian, chess player, chess author, and composer of endgame studies.
He was one of the principal proponents of hypermodernism in chess. With the exc ...
) when they forgot that the king or rook had previously moved and returned to its home square, and has not always been noticed by the opponent.
Yasser Seirawan
Yasser Seirawan ( ar, ياسر سيروان; born March 24, 1960) is a Syrian-born American chess grandmaster and four-time United States champion. He won the World Junior Chess Championship in 1979. Seirawan is also a published chess author an ...
once even accidentally castled queenside as White with his queen's rook on b1 (which was not allowed), and
Alexander Alekhine
Alexander Aleksandrovich Alekhine, ''Aleksándr Aleksándrovich Alékhin''; (March 24, 1946) was a Russian and French chess player and the fourth World Chess Champion, a title he held for two reigns.
By the age of 22, Alekhine was already a ...
once "castled his queen" (moving his queen from d1 to b1 and his rook from a1 to c1, which was also not allowed).
To clarify:
* The rook can be under attack.
* The rook can pass through an attacked square. (White can castle queenside even if Black is attacking b1; Black can castle queenside even if White is attacking b8.)
* The king can have been in check earlier in the game.
Tournament rules
Under the FIDE rules and enforced in most
tournaments
A tournament is a competition involving at least three competitors, all participating in a sport or game. More specifically, the term may be used in either of two overlapping senses:
# One or more competitions held at a single venue and concentr ...
, castling is considered a king move, so the king must be touched first; if the rook is touched first, a rook move must be played instead. As usual, the player may choose another legal destination square for the king until releasing it. When the two-square king move is completed, however, the player is committed to castling if it is legal, and the rook must be moved accordingly. The entire move must be completed with one hand. A player who attempts to castle illegally must return the king and rook to their original squares and then make a legal king move if possible (which may include castling on the other side). If there is no legal king move, the touch-move rule does not apply to the rook.
Under
US Chess Federation
The United States Chess Federation (also known as US Chess or USCF) is the governing body for chess competition in the United States and represents the U.S. in FIDE, the World Chess Federation. US Chess administers the official national rating s ...
rules, a player who intends to castle and touches the rook first would suffer no penalty and would be permitted to castle, provided castling is legal in the position. These tournament rules are not commonly enforced in nor commonly known by casual players.
Castling rights
An unmoved king has ''castling rights'' with an unmoved rook of the same color on the same rank. In the context of
threefold and fivefold repetition, two positions with different castling rights are considered to be different positions.
Example of castling rights
In a 1986 game between
Anatoly Karpov
Anatoly Yevgenyevich Karpov ( rus, links=no, Анато́лий Евге́ньевич Ка́рпов, p=ɐnɐˈtolʲɪj jɪvˈɡʲenʲjɪvʲɪtɕ ˈkarpəf; born May 23, 1951) is a Russian and former Soviet chess grandmaster, former World Ches ...
and
Tony Miles
Anthony John Miles (23 April 1955 – 12 November 2001) was an English chess player and the first Englishman to earn the Grandmaster title.
Early and personal life
Miles was an only child, born 23 April 1955 in Edgbaston, a suburb of Birming ...
, play continued from the diagrammed position as follows:
: 22... Ra4 23. Nc3 Ra8 24. Nb5 Ra4 25. Nc3 Ra8 26. Nb5
With his 26th move, Karpov attempted to claim a draw by threefold repetition, thinking that the positions after his 22nd, 24th, and 26th moves were the same. It was pointed out to him, however, that the position after his 22nd move had different castling rights than the positions after his 24th and 26th moves, rendering his claim illegal. As a result, Karpov was penalized three minutes on his clock. However, Miles decided to
agree to a draw anyway.
[
]
Notation
Both algebraic notation and descriptive notation indicate kingside castling as 0-0 and queenside castling as 0-0-0 (using the digit zero). Portable Game Notation
Portable Game Notation (PGN) is a standard plain text format for recording chess games (both the moves and related data), which can be read by humans and is also supported by most chess software.
History
PGN was devised around 1993, by Steven J. ...
and some publications use O-O for kingside castling and O-O-O for queenside castling (using the letter O) instead. ICCF numeric notation
ICCF numeric notation is the official chess notation system of the International Correspondence Chess Federation. The system was devised for use in international correspondence chess to avoid the potential confusion of using algebraic notation, ...
indicates castling based on the starting and ending squares of the king; thus, castling kingside is written as 5171 for White and 5878 for Black, and castling queenside is written as 5131 for White and 5838 for Black.
History
Castling has its roots in the ''king's leap''. There were two forms of the leap: the king would move once like a knight
A knight is a person granted an honorary title of knighthood by a head of state (including the Pope) or representative for service to the monarch, the church or the country, especially in a military capacity. Knighthood finds origins in the Gr ...
, or the king would move two squares on its first move. The knight move might be used early in the game to get the king to safety or later in the game to escape a threat. This second form was played in Europe as early as the 13th century. In North Africa, the king was transferred to a safe square by a two-move procedure: the king moved to the player's second , and the rook and king moved to each other's original squares.
Various forms of castling were developed due to the spread of rulesets during the 15th and 16th centuries which increased the power of the queen
Queen or QUEEN may refer to:
Monarchy
* Queen regnant, a female monarch of a Kingdom
** List of queens regnant
* Queen consort, the wife of a reigning king
* Queen dowager, the widow of a king
* Queen mother, a queen dowager who is the mother ...
and bishop
A bishop is an ordained clergy member who is entrusted with a position of authority and oversight in a religious institution.
In Christianity, bishops are normally responsible for the governance of dioceses. The role or office of bishop is ca ...
, allowing these pieces to attack from a distance and from both sides of the board, thus increasing the importance of king safety.
The rule of castling has varied by location and time. In medieval England, Spain, and France, the white king was allowed to jump to c1, c2, d3, e3, f3, or g1 if no capture was made and the king was not in check and did not move over check; the black king might move analogously. In Lombardy, the white king might also jump to a2, b1, or h1, with corresponding squares applying to the black king. Later, in Germany and Italy, the rule was changed such that the king move was accompanied by a pawn
Pawn most often refers to:
* Pawn (chess), the weakest and most numerous piece in the game
* Pawnbroker or pawnshop, a business that provides loans by taking personal property as collateral
Pawn may also refer to:
Places
* Pawn, Oregon, an his ...
move.
In the Göttingen manuscript
The Göttingen manuscript is the earliest known work devoted entirely to modern chess. It is a Latin text of 33 pages held at the University of Göttingen. A quarto parchment manuscript of 33 pages, ff. 1–15a are a discussion of twelve chess op ...
(c. 1500) and a game published by Luis Ramírez de Lucena
Luis Ramírez de Lucena (c. 1465 – c. 1530) was a Spanish chess player who published the first extant chess book. He is believed to be the son of humanist writer and diplomat Juan de Lucena.
Book
Lucena wrote the oldest surviving printed boo ...
in 1498, castling consisted of moving the rook and then moving the king on separate moves.
The current version of castling was established in France in 1620 and in England in 1640.
In Rome, from the early 17th century until the late 19th century, the rook might be placed on any square up to and including the king's square, and the king might be moved to any square on the other side of the rook. This was called ''free castling''.
In the 1811 edition of his chess treatise, Johann Allgaier
Johann Baptist Allgaier (June 19, 1763, Schussenried – January 3, 1823, Vienna) was a German-Austrian chess master and theoretician. He was also the author of the first chess handbook in German – ''Neue theoretisch-praktische Anweisung zum Sch ...
introduced the 0-0 notation. He differentiated between 0-0r (right) and 0-0l (left). The 0-0-0 notation for queenside castling was introduced in 1837 by Aaron Alexandre
Aaron (Albert) Alexandre ( he, אהרון אלכסנדר, around 1765/68 in Hohenfeld, Franconia – 16 November 1850 in London, England) was a German– French–English chess player and writer.
Aaron Alexandre, a Bavarian trained as a rabbi, ar ...
. The practice was adopted in the first edition (1843) of the influential ''Handbuch des Schachspiels
''Handbuch des Schachspiels'' (''Handbook of Chess'', often simply called the ''Handbuch'') is a chess book, first published in 1843 by Tassilo von Heydebrand und der Lasa. It was a comprehensive reference book on the game, and one of the most imp ...
'' and soon became standard. In English descriptive notation
Descriptive notation is a chess notation system based on abbreviated natural language. Its distinctive features are that it refers to files by the piece that occupies the back rank square in the starting position and that it describes each square t ...
, the word "Castles" was originally spelled out, adding "K's R" or "Q's R" if disambiguation was needed; eventually, the 0-0 and 0-0-0 notation was borrowed from the algebraic system.
Strategic and tactical concepts
Strategy
Castling is generally an important goal in the opening
Opening may refer to:
* Al-Fatiha, "The Opening", the first chapter of the Qur'an
* The Opening (album), live album by Mal Waldron
* Backgammon opening
* Chess opening
* A title sequence or opening credits
* , a term from contract bridge
* , ...
: it moves the king to safety away from the of the board, and it moves the rook to a more active position (the f-file if castling kingside; the d-file if castling queenside).
The choice regarding to which side one castles often hinges on an assessment of the trade-off between king safety and activity of the rook. Kingside castling is generally slightly safer because the king ends up closer to the edge of the board and can usually defend all of the pawns on the castled side. In queenside castling, the king is placed closer to the center and does not defend the pawn on the a-; for these reasons, the king is often subsequently moved to the b-file. In addition, queenside castling is initially obstructed by more pieces than kingside castling, thus taking longer to set up than kingside castling. On the other hand, queenside castling places the rook more efficiently on the central d-file, where it is often immediately active; meanwhile, with kingside castling, a tempo
In musical terminology, tempo (Italian, 'time'; plural ''tempos'', or ''tempi'' from the Italian plural) is the speed or pace of a given piece. In classical music, tempo is typically indicated with an instruction at the start of a piece (often ...
may be required to move the rook to a more effective square.
Players may forgo castling for various reasons. In positions where the opponent cannot organize an attack against a centralized king, castling may be unnecessary or even detrimental. In addition, in certain situations, a rook can be more active near the edges of the board than in the center; for example, if it is able to fight for control of an open or semi-open file.
Kingside castling occurs more frequently than queenside castling. It is common for both players to castle kingside, somewhat uncommon for one player to castle kingside and the other queenside, and somewhat rare for both players to castle queenside. If one player castles kingside and the other queenside, it is called ''opposite castling'' or ''opposite-side castling''. Castling on opposite sides usually results in a fierce fight, as each player's pawns are free to advance to attack the opponent's castled position without exposing the player's own castled king. Opposite castling is a common feature of many openings, such as the Yugoslav Attack.
Tactics involving castling
Tactical patterns involving castling are rare. One pattern involves castling queenside to deliver a : the king attacks a rook (on b2 for White or b7 for Black), while the rook attacks a second enemy piece (usually the king). In the example shown, from the game Mattison–Millers, Königsberg 1926, Black played 13...Rxb2 and resigned after 14.0-0-0+, which wins the rook.
Chess historian Edward Winter has proposed the name "Thornton castling trap" for this pattern, in reference to the earliest known example, Thornton–Boultbee, published in the ''Brooklyn Chess Chronicle'' in 1884. Other chess writers such as Gary Lane have since adopted this term.
Another example of tactical castling is illustrated in the diagrammed position from the correspondence game Gurvich–Pampin, 1976. After 1.Qxd8+ Kxd8 2.0-0-0+ Ke7 3.Nxb5, White wins a rook by castling with check and simultaneously unpinning the knight.
Such a double attack can also be made by castling kingside, although this is much rarer. In this position from the blindfold game , 2007, the move 19...0-0 threatens to win the h7-rook as well as indirectly threatens to deliver back-rank mate. Black will thus win the g5-knight next move; 20.Rh6 Bxg5 21.Rxg6+ Kh7 22.Rxg5 would not work, as it would be met by 22...Rf1.
Examples
* Viktor Korchnoi
Viktor Lvovich Korchnoi ( rus, Ви́ктор Льво́вич Корчно́й, p=vʲiktər lʲvovʲɪtɕ kɐrtɕˈnoj; 23 March 1931 – 6 June 2016) was a Soviet (before 1976) and Swiss (after 1980) chess grandmaster (GM) and chess writer. He ...
, in his 1974 Candidates final match with Anatoly Karpov
Anatoly Yevgenyevich Karpov ( rus, links=no, Анато́лий Евге́ньевич Ка́рпов, p=ɐnɐˈtolʲɪj jɪvˈɡʲenʲjɪvʲɪtɕ ˈkarpəf; born May 23, 1951) is a Russian and former Soviet chess grandmaster, former World Ches ...
, asked the arbiter if castling was legal when the castling rook was under attack. The arbiter answered in the affirmative, Korchnoi executed the move, and Karpov resigned shortly after.
* Castling occurred three times in the game Wolfgang Heidenfeld
Wolfgang Heidenfeld (; 29 May 1911 – 3 August 1981) was a German chess player and chess composer.
Heidenfeld was born in Berlin. He was forced to move from Germany to South Africa in the 1930s because he was a Jew. There, he won the South Afr ...
– Nick Kerins, Dublin 1973. The third instance of castling, the second one by White, was illegal, as the white king had already moved. The game is as follows:
*:1.e4 e6 2.d4 d5 3.Be3 Nf6 4.e5 Nfd7 5.f4 c5 6.c3 Nc6 7.Nf3 Qb6 8.Qd2 c4 9.Be2 Na5 10.0-0 f5 11.Ng5 Be7 12.g4 Bxg5 13.fxg5 Nf8 14.gxf5 exf5 15.Bf3 Be6 16.Qg2 0-0-0 17.Na3 Ng6 18.Qd2 f4 19.Bf2 Bh3 20.Rfb1 Bf5 21.Nc2 h6 22.gxh6 Rxh6 23.Nb4 Qe6 24.Qe2 Ne7 25.b3 Qg6+ 26.Kf1 Bxb1 27.bxc4 dxc4 28.Qb2 Bd3+ 29.Ke1 Be4 30.Qe2 Bxf3 31.Qxf3 Rxh2 32.d5 Qf5 33.0-0-0 Rh3 34.Qe2 Rxc3+ 35.Kb2 Rh3 36.d6 Nec6 37.Nxc6 Nxc6 38.e6 Qe5+ 39.Qxe5 Nxe5 40.d7+ Nxd7
Averbakh vs. Purdy
In the game Yuri Averbakh
Yuri Lvovich Averbakh (russian: Ю́рий Льво́вич Аверба́х; 8 February 1922 – 7 May 2022) was a Russian chess grandmaster and author. He was chairman of the USSR Chess Federation from 1973 to 1978. He was the first centenaria ...
–Cecil Purdy
Cecil John Seddon Purdy (27 March 1906 – 6 November 1979), often referred to as "C. J. S. Purdy", was an Australian chess player and writer. He was awarded the titles International Master in 1951 and Grandmaster of correspondence chess in ...
, Adelaide
Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...
1960, when Purdy castled queenside, Averbakh queried the move, pointing out that the rook had passed over an attacked square. Purdy indicated e8 and c8 and said, "The king", in an attempt to explain that this was forbidden only for the king. Averbakh replied, "Only the king? Not the rook?" Averbakh's colleague Vladimir Bagirov
Vladimir Konstantinovich Bagirov ( rus, Влади́мир Константи́нович Баги́ров; lv, Vladimirs Bagirovs; August 16, 1936 – July 21, 2000) was a Soviet- Latvian chess player, author, and trainer. He played in ten USS ...
then explained the castling rules to him in Russian, and the game continued.
Edward Lasker vs. Thomas
In the game Edward Lasker
Edward Lasker (born Eduard Lasker) (December 3, 1885 – March 25, 1981) was a German-American chess and Go player. He was awarded the title of International Master of chess by FIDE. Lasker was an engineer by profession, and an author of ...
– Sir George Thomas (London 1912), White could have checkmate
Checkmate (often shortened to mate) is any game position in chess and other chess-like games in which a player's king is in check (threatened with ) and there is no possible escape. Checkmating the opponent wins the game.
In chess, the king is ...
d with 18.0-0-0, but he instead played 18.Kd2#. (See Edward Lasker's notable games.)
Prins vs. Day
The diagram shows the final position of the game Lodewijk Prins
Lodewijk Prins (27 January 1913, Amsterdam – 11 November 1999) was a Dutch chess player and referee of chess competitions.
Prins was awarded the International Master title in 1950, and was made an International Arbiter in 1960. In 1982 FI ...
–Lawrence Day
Lawrence Alexander Day (born 1 February 1949 in Kitchener, Ontario) is a Canadian chess player, author, and journalist who holds the FIDE title of International Master. He represented Canada at 13 Chess Olympiads.
Early life
As a youth in Ot ...
(1968), where White resigned. Had the game continued, Black could have checkmated by castling:
:29. Kf6 Qf5+ 30. Kg7 Qg6+ 31. Kh8 0-0-0
(See Lawrence Day's notable chess games.)
Feuer vs. O'Kelly
In the 1934 Belgian Championship, Otto Feuer caught Albéric O'Kelly in the Thornton castling trap. In the position in the diagram, the game continued 10...Rxb2 11.dxe5 dxe5?? 12.Qxd8+ Kxd8 13.0-0-0+, and O'Kelly resigned. Feuer's last move simultaneously gave check and attacked the rook on b2.
Fischer vs. Najdorf
The diagram illustrates the consequences of losing castling rights. Fischer
Fischer is a German occupational surname, meaning fisherman. The name Fischer is the fourth most common German surname. The English version is Fisher.
People with the surname A
* Abraham Fischer (1850–1913) South African public official
* Ad ...
, with the white pieces, played 16.Ng7+ Ke7 17.Nf5+ Ke8. Although all the pieces were now on the same squares, the two positions were not identical because Black, having moved his king, no longer had the right to castle. White now had time to build pressure on the black king without worrying that the king might escape by castling.
Artificial castling
''Artificial castling'', also known as ''castling by hand'', is a maneuver whereby a player achieves a castled position without the use of castling.
Example of artificial castling
In the first diagram:
:1. Nxe5 Bxf2+
Black sees that if he plays 1...Nxe5, White responds with 2.d4, winning back the minor piece with a fork
In cutlery or kitchenware, a fork (from la, furca 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods ei ...
and taking control of the center. Instead of allowing this, Black hopes to cause trouble for White by returning the piece while depriving White of the right to castle. White can easily castle artificially, however. For example:
:2. Kxf2 Nxe5 3. Rf1
White begins castling artificially.
:3... Ne7 4. Kg1 (second diagram)
White has achieved a normal castled position via several moves. With the bishop pair and a central pawn majority, White has a slight advantage.
Castling in chess variants
Variants of Western chess often include castling in their rulesets, sometimes in a modified form.
In variants played on a standard 8×8 board, castling is often the same as in standard chess. This includes variants that replace the king with a different royal piece, as is the case with the knight in Knightmate. Some variants, however, have different rules; for example, in Chess960
Fischer random chess, also known as Chess960 (often read in this context as 'chess nine-sixty' instead of 'chess nine hundred sixty'), is a variation of the game of chess invented by the former world chess champion Bobby Fischer. Fischer announ ...
, the king may move more or fewer than two squares (including none) when castling, depending on the starting position.
Castling can also be adapted to variants with different board sizes and shapes. Some such variants, like Capablanca chess
Capablanca chess (or Capablanca's chess) is a chess variant invented in the 1920s by World Chess Champion José Raúl Capablanca. It incorporates two new pieces and is played on a 10×8 board. Capablanca believed that chess would be played out i ...
(10×8) or chess on a really big board (16×16), preserve the castling movement of the rooks, meaning that the king moves a different distance along the . In a few variants, most notably Wildebeest chess (11×10), the player may choose to move the king any distance and move the rook accordingly.
Castling sometimes features in chess variants not played on a square grid, such as masonic chess, triangular chess, Shafran's and Brusky's hexagonal chess, and millennium 3D chess
Millennium 3D chess is a three-dimensional chess variant created by William L. d'Agostino in 2001. It employs three vertically stacked 8×8 boards, with each player controlling a standard set of chess pieces. The inventor describes his objective ...
. In '' 5D Chess with Multiverse Time Travel'', castling is possible within the spatial dimensions but not across time or between timelines.
Some chess variants do not feature castling, such as losing chess, where the king is not , and Grand Chess
Grand Chess is a large-board chess variant invented by Dutch games designer Christian Freeling in 1984. It is played on a 10×10 board, with each side having two additional pawns and two new pieces: the ''marshal'' and the ''cardinal''.
* The ...
, where the rooks have significantly more opening mobility.
In a handicap game with rook odds, the player giving odds may castle with the absent rook, moving only the king.
Chess without castling
Writing in 2019, former world chess champion Vladimir Kramnik
Vladimir Borisovich Kramnik (russian: Влади́мир Бори́сович Кра́мник; born 25 June 1975) is a Russian chess grandmaster. He was the Classical World Chess Champion from 2000 to 2006, and the undisputed World Chess Cha ...
proposed a variant of chess without castling. This variant would reduce king safety, theoretically leading to more dynamic games, as it would be considerably harder to force a draw and the pieces would be forced to engage in a mêlée. In 2021, former world champion Viswanathan Anand
Viswanathan "Vishy" Anand (born 11 December 1969) is an Indian chess grandmaster and a former five-time World Chess Champion. He became the first grandmaster from India in 1988, and is one of the few players to have surpassed an Elo rating of ...
defeated Kramnik 2½–1½ in a no-castling exhibition match under classical time controls.
Castling in chess problems
Castling features in some chess problem
A chess problem, also called a chess composition, is a puzzle set by the composer using chess pieces on a chess board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to ...
s. The earliest known study containing castling was published in 1843 by Julius Mendheim.
Retrograde analysis
Castling is common in retrograde analysis
In chess problems, retrograde analysis is a technique employed to determine which moves were played leading up to a given position. While this technique is rarely needed for solving ordinary chess problems, there is a whole subgenre of chess pr ...
problems. By chess problem convention, if a player's king and rook are on their original squares, the player is assumed to have castling rights unless it can be proved otherwise. In some retrograde analysis problems, the solver (who usually plays White) is required to prove that the opponent has previously moved their king or rook and therefore cannot castle. This is sometimes accomplished by castling or by capturing ''en passant'', thereby disproving other possible game histories.
The diagram shows a mate in two. 1.Rad1 0-0 does not work. The is 1.0-0-0 This demonstrates that the white king has not moved yet and that the rook on d4 must therefore be a promoted piece. Therefore, either the black king or black rook has previously moved to let the white rook off the back rank. Therefore Black cannot castle. After any move by Black, 2.Rd8 is mate.
Novelty problems
Some joke chess problems involve castling with a promoted rook of the opponent's color. In orthodox chess, this would be illegal since the rook would be giving check to the king, but under fairy chess conditions, this might not actually be check.
The diagrammed problem involves castling with an opposing rook under the Koko fairy condition (each piece must end up adjacent to another piece when moving). The solution (Black's move being given first per helpmate convention) is:
:1. Bg7 h8=R 2. Bf6 Kg6 3. 0-0 Kh7#
where, after 3.0-0, White's rook is not checking the king; a hypothetical capture of the king would result in the rook not being adjacent to any other piece, which is illegal under the Koko condition.
The allowance of castling with a "phantom rook" in handicap games has also been used in joke problems. Many other joke variations on castling are possible.
Vertical castling
In 1907, C. Staugaard composed a two-mover
A chess problem, also called a chess composition, is a puzzle set by the composer using chess pieces on a chess board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to ...
in which White promotes a pawn to a rook and then castles vertically with the newly promoted rook (placing the king on e3 and the rook on e2), since the rook has not moved. In the position on the right, White plays 1.e8=R, and after the forced move 1...Kxc2 castles vertically with the promoted rook, checkmating Black.
Vertical castling, also known as "Staugaard castling" or "Pam–Krabbé castling", has been used in a few novelty chess problems.
Tim Krabbé
Tim Krabbé (born 13 April 1943) is a Dutch journalist, novelist and chess player.
Krabbé was born in Amsterdam. His writing has appeared in most major periodicals in the Netherlands. Once a competitive cyclist, he is known to Dutch readers for ...
's 1985 book ''Chess Curiosities'' includes a problem featuring vertical castling, along with an incorrect claim that the problem's 1973 publication prompted FIDE
The International Chess Federation or World Chess Federation, commonly referred to by its French acronym FIDE ( Fédération Internationale des Échecs), is an international organization based in Switzerland that connects the various national c ...
to amend the castling laws in 1974 to add the requirement that the king and rook be on the same rank. In reality, the original FIDE Laws from 1930 explicitly stated that castling must be done with a king and a rook on the same rank (''traverse'' in French).''Règle du Jeu d’Échecs de la F. I. D. E. (édition officielle 1930)''
(in French), FIDE, 1930 (via wikisource) It is unclear whether any historically published sets of rules would technically allow such a move.
Nomenclature
In most European languages, the term for castling is derived from the Persian ''rukh'' (e.g. ''rochieren'', ''rochada'', ''enroque''), while queenside and kingside castling are referred to using the adjectives meaning "long" and "short" (or "big" and "small"), respectively.
References
Bibliography
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External links
"Mate by Castling" game collectionat
Chessgames.com
Chessgames.com is an Internet chess community with over 224,000 members. The site maintains a large database of chess games, where each game has its own discussion page for comments and analysis. Limited primarily to games where at least one pla ...
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