The rook (/rʊk/; ♖, ♜) is a piece in the game of chess. It may move any number of squares horizontally or vertically without jumping, and it may capture an enemy piece on its path; it may participate in castling. Each player starts the game with two rooks, one in each corner on their side of the board.
Formerly, the rook (from Persian رخrokh/rukh, meaning "chariot")[1][2][3] was alternatively called the tower, marquess, rector, and comes (count or earl).[4] The term "castle" is considered to be informal or old-fashioned.[5][6]
^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".