Keys "s"=save "l"=load "b"=back once
Each turn, your opponent may refuse one of your moves. If you have only one move, it is checkmate or stalemate depending on the circumstances. Attributed to Fred Galvin, 1958.
A bug which did not allow a line-mover to cross a forbidden square was found and corrected by me 5/23/03. This produced a second bug which was corrected 6/5/03. Thanks Dale Hawthorne for pointing this out. I am sorry for any inconvenience.
Compromise Chess, in which the opponent chooses between two of your proposed moves, is more suited for correspondence play than over-the-board play, according to Pritchard.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!