Keys "s"=save "l"=load "b"=back once
A 3-D chess variant from Texas Educational Devices, 1966, for psychological experiments. Knights move one square diagonally in any direction. I have the fifty move rule kick in if there have been no pawn moves on the same level. Pritchard says nothing about pawn promotion. I let them promote when they reach the opposite side.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!