A rook (♖ ♜ borrowed from Persian رخ rokh, Sanskrit रथ rath, “chariot”) is a piece in the strategy board game of chess. Formerly the piece was called the castle, tower, marquess, rector, and comes (Sunnucks 1970). The informal term “castle” is deprecated.
Each player starts the game with two rooks, one in each of the corner squares on his own side of the board.
 Initial placement and movement
|This section uses algebraic notation to describe chess moves.|
In algebraic notation, the white rooks start on squares a1 and h1, while the black rooks start on a8 and h8. The rook moves horizontally or vertically, through any number of unoccupied squares (see diagram). As with captures by other pieces, the rook captures by occupying the square on which the enemy piece sits. The rook also participates, with the king, in a special move called castling.
In the medieval shatranj, the rook symbolized a chariot. The Persian word rukh means chariot (Davidson 1949:10), and the corresponding pieces in Oriental chess games such as xiangqi and shogi have names also meaning chariot (車).
Persian war chariots were heavily armoured, carrying a driver and at least one ranged-weapon bearer, such as an archer. The sides of the chariot were built to resemble fortified stone work, giving the impression of small, mobile buildings, causing terror on the battlefield. However, in the West the rook is almost universally represented as a crenellated turret. (One possible explanation is that when the game was imported to Italy, the Persian rukh became the Italian word rocca, meaning fortress. Another possible explanation is that rooks represent siege towers – the piece is called torre, meaning tower, in Italian, Portuguese, and Spanish; tour in French; toren in Dutch; Turm in German; and Torn in Swedish. An alternative name in Russian: Тура (pronounced as Toura). Finally, the chariot was sometimes represented as a silhouette, a square with two points above representing the horse’s heads, which may have been seen to resemble a building with arrowports to the medieval imagination.) An exception is seen in the British Museum’s collection of the medieval Lewis chess pieces in which the rooks appear as stern warders or wild-eyed Berzerker warriors. Rooks usually are similar in appearance to small castles, and as a result a rook is sometimes called a “castle” (Hooper & Whyld 1992). This usage was common in the past (“The Rook, or Castle, is next in power to the Queen” – Howard Staunton, 1847) but today it is rarely if ever used in chess literature or among players, except in the expression “castling.”
The Russian name for the rook (ladya) means a sailing boat or longship of Northern cultures such as the Vikings.
 Relative value
In general, rooks are stronger than bishops or knights (which are called minor pieces) and are considered greater in value than either of those pieces by nearly two pawns but less valuable than two minor pieces. Two rooks are generally considered to be worth slightly more than a queen (see chess piece relative value). Winning a rook for a bishop or knight is referred to as winning the exchange. Rooks and queens are called heavy pieces or major pieces, as opposed to bishops and knights, the minor pieces.
In the opening, the rooks are blocked in by other pieces and cannot immediately participate in the game; so it is usually desirable to connect one’s rooks on the first rank by clearing all pieces except the king and rooks from the first rank and then castling. In that position, the rooks support each other, and can more easily move to occupy and control the most favorable files.
A common strategic goal is to place a rook on the first rank of an open file (i.e. one unobstructed by pawns of either player), or a half-open file (i.e., one unobstructed by friendly pawns). From this position, the rook is relatively unexposed to risk but can exert control on every square on the file. If one file is particularly important, a player might advance one rook on it, then position the other rook behind – doubling the rooks.
A rook on the seventh rank (the opponent’s second rank) is typically very powerful, as it threatens the opponent’s unadvanced pawns and hems in the enemy king. A rook on the seventh rank is often considered sufficient compensation for a pawn (Fine & Benko 2003:586). In the diagrammed position from a game between Lev Polugaevsky and Larry Evans, the rook on the seventh rank enables White to draw, despite being a pawn down (Griffiths 1992:102–3).
Rooks are most powerful towards the end of a game (i.e., the endgame), when they can move unobstructed by pawns and control large numbers of squares. They are somewhat clumsy at restraining enemy pawns from advancing towards promotion, unless they can occupy the file behind the advancing pawn. By the same token, a rook best supports a friendly pawn towards promotion from behind it on the same file (see Tarrasch rule).
In a position with a rook and one or two minor pieces versus two rooks, generally in addition to pawns, and possibly other pieces – Lev Alburt advises that the player with the single rook should avoid exchanging the rook for one of his opponent’s rooks (Alburt 2009:44).
The rook is a very powerful piece to deliver checkmate. Below are a few examples of rook checkmates that are easy to force.
In heraldry, chess rooks are often used as charges. Unlike a real chess rook, they are conventionally shown with two outward-curving horns. This is because they would otherwise appear to be castle towers, since there is no proportion on a coat of arms. This charge is always blazoned “chess rook” so as not to be confused with the bird of that name; it is also not to be confused with the zule, a similar-looking object with two outward-curving horns at both top and bottom.
In Canadian heraldry, the chess rook is the brisure of the fifth daughter.
Unicode defines two codepoints for rook:
♖ U+2656 White Chess Rook (HTML ♖)
♜ U+265C Black Chess Rook (HTML ♜)
 See also
- Chess piece relative value
- Lucena position – winning position
- Philidor position – drawing position
- Rook and pawn versus rook endgame
- Staunton chess set
- Tarrasch rule – rooks belong behind passed pawns
- The exchange (chess) – a rook for a minor piece
- Oxford English Dictionary 2nd ed. (online version, accessed Jan. 27, 2009), entry for “Castle”, def. 9. “Chess. One of the pieces, made to represent a castle; also called a ROOK.”. New Oxford American Dictionary, 2nd ed. (2005) says that “castle” is informal and an “old-fashioned term for rook”. The Oxford Companion to Chess, by David Hooper & Kenneth Whyld, 2nd ed. (1992), p. 344 says “In English-speaking countries non-players sometimes call it a castle…”. Let’s Play Chess by Bruce Pandolfini (1986) p. 30, says “The rook is the piece mistakenly called the castle.”; The Everything Chess Basics Book by Peter Kurzdorfer and the United States Chess Federation, Adams Media 2003, page 30, says “… often incorrectly referred to as a castle by the uninitiated”.
- The Official Rules of Chess by Eric Schiller, The US Chess Federation Official Rules of Chess (five editions by various authors), Official Chess Handbook, by Kenneth Harkness, Official Chess Rulebook by Harkness, and The Official Laws of Chess by FIDE (two editions) all use only the term “rook”. Books for beginners such as Bobby Fischer Teaches Chess, A World Champion’s Guide to Chess by Susan Polgar, The Complete Book of Chess by I. A. Horowitz & P. L. Rothenberg, and Chess Fundamentals by José Capablanca (2006 revision by Nick de Firmian) also only mention “rook”.
- 現代漢語詞典 ISBN 978-962-07-0211-2
- Lasker 1947, p. 8: “The name “Castle” is rarely if ever used in modern chess literature for this piece.” Horton 1959, p. 175: “Sometimes the Rook has been called a “Castle” but in modern chess literature this term is rarely, if ever, used.”
- Polugaevsky vs. Evans
- The two rooks are sometimes colloquially referred to as “pigs on the seventh”, because they often threaten to “eat” the opponent’s pieces or pawns.
- Alburt, Lev (December 2009), “Back to Basics”, Chess Life 2009 (12): 44–45
- Brace, Edward R. (1977), “rook”, An Illustrated Dictionary of Chess, Hamlyn Publishing Group, pp. 241–42, ISBN 1-55521-394-4
- Barden, Leonard (1980), Play Better Chess with Leonard Barden, Octopus Books Limited, p. 10, ISBN 0-7064-0967-1
- Fine, Reuben; Benko, Pal (2003), Basic Chess Endings (1941) (2nd ed.), McKay, ISBN 0-8129-3493-8
- Davidson, Henry (1949), A Short History of Chess, McKay, ISBN 0-679-14550-8 (1981 paperback)
- Griffiths, Peter (1992), Exploring the Endgame, American Chess Promotions, ISBN 0-939298-83-X
- Hooper, David; Whyld, Kenneth (1992), “rook”, The Oxford Companion to Chess (2nd ed.), Oxford University Press, ISBN 0-19-280049-3
- Horton, Byrne J. (1959), Dictionary of modern chess, New York: Philosophical Library, p. 175, ISBN 0-8065-0173-1, OCLC 606992
- Lasker, Emanuel (1947), Lasker’s Manual of Chess, David McKay Company, p. 8, ISBN 0-486-20640-8, OCLC 3636924
- Pandolfini, Bruce (1986), Let’s Play Chess, Fireside, ISBN 0-671-61983-7
- Sunnucks, Anne (1970), “rook, the”, The Encyclopaedia of Chess, St. Martins Press, ISBN 978-0-7091-4697-1
This article uses material from the Wikipedia article Rook (chess), which is released under the Creative Commons Attribution-Share-Alike License 3.0.