The great thing about Black Jack is that there are shed loads of variations to the rules and changing just one or two of the rules slightly results in a different game. It is also similar to Uno, a card game you can buy in shops that uses special 'Uno' cards. It seems to be played exclusively in the UK (as far as I can tell), although I've heard it's similar to the American game Crazy Eights.
Not to be confused with Blackjack/21/Pontoon, Black Jack is a totally different game.
