Answer:

rook

Answer	Crossword Clue
ROOK	Castling requirement
ROOK	Cheat
ROOK	Versification

ROOK	Chess piece
ROOK	Kasparov's piece
ROOK	One of Deep Blue's men
ROOK	He guards the corner of the chessboard
ROOK	Corner piece
ROOK	Castle
ROOK	Fischer's corner piece
ROOK	Straight mover, in chess

ROOK	Piece on a corner square
ROOK	Rank-and-file mover?
ROOK	Knight's neighbor
ROOK	One stuck in a corner
ROOK	Corner chess piece
ROOK	Rank-and-file chess piece
ROOK	Swindle
ROOK	Chess piece that can't move diagonally

ROOK	Castle, in chess
ROOK	Castle in a board game
ROOK	Fleece
ROOK	Hornswoggle
ROOK	Castle-shaped chess piece
ROOK	Movable castle
ROOK	Chess corner piece
ROOK	King and queen's attacker, at times

ROOK	Flimflam
ROOK	Chessman also called a castle
ROOK	Crow look-alike
ROOK	Chessboard castle
ROOK	Rank-and-file man
ROOK	Chesspiece
ROOK	Chess castle
ROOK	Corner chesspiece

ROOK	Castle on a board
ROOK	Castling piece
ROOK	Knight neighbor at the start of a chess game
ROOK	Piece that moves orthogonally
ROOK	Piece that starts a chess game on square a1