Plays the game of "42", which is a bidding-type dominoes game similar to bridge, spades, or pinochle. The computer plays the positions of three players, and you are the fourth. It also can be used to learn the game by suggesting plays, and explaining the reason for its suggestions.
What's new in this version:
Recent versions (since 3.17) add doubles high or low in Nel-O, plus the ability to play "sevens".