21-en is a known card game, which is played regularly by many. There are several versions of the rules in use. This program uses the most general rules, which will be familiar to almost everyone. In the game there are 52 playing cards. An ace is 1 or 11 points, king, queen and jack are 10 points and the cards 2 through 10 are 2 through 10 points. The objective is to get as close as possible to 21 without exceeding 21. Both players start with two cards. Each player may ask as many cards as she likes. The player with the most points without exceeding 21 wins.