The Rook or Castle *
(* The name "Castle" is rarely if ever used in modern chess literature for this piece.)
The Rook c2 has the following possible moves: to b2, d2, e2, f2 and capture of g2. It cannot go to c1 or c3 because it is under obligation to guard its King against the White Rook g2. The Rook c4 can go to a4 or b4 or d4 or capture e4 but cannot capture f4 because Rook e4,is an obstruction; it may also go to c8 or c7 or c6 or c5 or C3 but not to C2 or c1 owing to the obstruction of Rook C2. The Rook e4 has only two squares open to it, d4 and c4, and the Rook g2 no less than 12 squares, any square of the g line and all but two squares of the second row: h2, f2, e2, d2, c2, gi, g3, g4, g5, g6, g7, g8.