Keys "s"=save "l"=load "b"=back once
Units captured on one board join the reserves on the other board and may be added instead of moving a unit. Here "Bughouse Rules" are in effect, and you may place a unit to check or mate the opposing king. Promoted units that are passed revert to pawns. The first team to checkmate on one board wins. This is a very popular chess variant.
Chess and Tandem Chess
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!