2 or More
All players sit in a circle, and a player is nominated to start. That person starts the game by whispering a question to the person on their left, starting with “Who”. e.g. “Who has slept with the most people?”. That person must point to another player, and that person has to drink half of their drink.
If the player pointed at doesn’t want to drink, they can choose to have the question declared to the group. This can only be done twice by each player. If another player wants to know what the question was they can take a shot. The question is then whispered to them.
The idea is to pick really personal questions to make your friends drink.