Quote Originally Posted by Kevin Pacey View Post
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Regarding your second question, Even if a player is on the edge of being mated in some random position where he's down to almost nothing but an unmoved king and rook, if castling were legal then so would be moving the king sideways one step, I'd think.
Unless e.g. you are talking about Chess960 and Fischer castling. Then castling can be the only legal move in some cases - a no castling rule implemented for in the case of Chess960 could in the case of some starting positions mean a player might stalemated due to it (but not if castling were still legal), there.