Lasca (or Laska) is a game similar to Draughts but with some really cool enhancements. You'll find a great description in the help system of Ascal. In the meantime the article on Wikipedia and on http://research.interface.co.uk/lasca/about.htm will help you understanding the rules. Ascal tries to give a great Gnome Version of Lasca for one and two players. You can undo moves, save and load games and all that on a nifty graphical board.