1 the rules of the game and the goal for winning are ever changing
2 the basic rules of simple and easy to under stand
3 needs at lest 3 players with no upper limit
4 only one person can win the game but even with no cards a person is not out of the game
5 you are invested in the turns of the other players as well as your own
6 has a reasonable amount of play time that only slightly varies between games