Object: Checkmate the opponent's King.
 
Whenever a white piece hits the eighth rank (for Black the first rank), it is allowed to promote into a Knight, a Bishop, a Rook or a Queen.
 
In variant 2 each piece promotes to a piece of the next higher value: a Pawn to a Knight, Knight to Bishop, Bishop to Rook, Rook to Queen, Queen stays.
 
In variant 3 each piece promotes as follows: a Pawn to a Queen, Queen to a Rook, Rook to Bishop, Bishop to Knight, Knight stays.
 
Apart from this, the standard chess rules apply.
 
 
More freeware as well as real puzzles and games at my home page: http://karl.kiwi.gen.nz/.