Keys "s"=save "l"=load "b"=back once
You may move either side's units. If a position occurs in which you are in checkmate, as in a regular chess game, you lose. No reversing the previous player's move. Chris Taylor, early 1970's. In the related variant, Free-For-All Chess, you may reverse the previous move.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!