The rules of Nomic Chess start out like regular chess, except that when it is your turn, instead of making a move, you can change the rules such that any particular class of pieces (say pawns) can move like any other class of pieces (say queens).<\/p>\n
An optional second rule is that when you are in check, you must make a move, not a rule change, in order to get out of check. (Otherwise it can be extremely difficult to arrive at a checkmate if any attacking piece can be turned into one that moves like a pawn or whatever).<\/p>\n