Object: Checkmate the opponent's King.
 
Pawns move and capture as usual.
 
Every other piece type, however, can only move to an empty square.
Captures are executed in a mirror-like fashion, exactly opposite to where you move: A move (to an empty square) will capture an opponent's piece if the opponent's piece is diametral opposite to the target square of the move, with the from-position as the center of this point-symmetry. E.g. Rook h4-h3 captures an opponent's piece on h5. Try out a few pieces to see how it works.
 
Friendly pieces are not captured.
 
In variant 2 the Pawns capture in mirror-fashion, too. Note that in this variant even En-passant is mirrored: Pc7-c5 may be answered by Pb7-a8xc6 !
 
 
More freeware as well as real puzzles and games at my home page: http://karl.kiwi.gen.nz/.