From: utzoo!decvax!duke!bcw
Newsgroups: net.chess
Title: Re: bug in chess program
Article-I.D.: duke.2798
Posted: Thu Dec  2 23:40:15 1982
Received: Fri Dec  3 07:54:33 1982

From:	Bruce C. Wright @ Duke University
Re:	Chess bug

No, no, no!  It is *not* illegal to castle when one or more of the squares
between the King and the Rook are under enemy attack;  it is only illegal
to castle when

	1)  The King or the Rook has moved previously;
	2)  The King is in check;
	3)  There are nonempty squares between the King and the Rook;
	4)  The King will move over or onto a square which is attacked
	    by an enemy piece.

Note that it says nothing about attacks on the Rook or the squares
over which the Rook moves - if the chess program disallows castling
when the Rook is moving out of/over attacked squares, it is an
evident bug in the program.

			Bruce C. Wright @ Duke University