You need at least four people and a dice cup with five dice. Pick someone to start and they roll all five dice. All "1"s that are rolled are removed and the person continues to roll until they have a roll that produces no "1"s. Keep track of how many "1"s were rolled. The cup is then passed to the next person who rolls all five dice, taking out any "1"s they might get. If on your first roll you don't get any "1"s you pass the cup.
The person that rolls the 7th "1" gets to pick the shot, the person who rolls the 14th "1" has to pay for the shot, and the person who rolls the 21st "1" has to drink it. Can be a brutal game if you get people picking nasty drinks.