3 or More
Place a glass in the centre of the table. A player then starts by filling the glass with drink. Keeping in mind that any player could end up drinking the contents of the glass.
Every player puts a finger on the rim of the glass. Each player takes a turn counting down from 3, and every other player decides if they should keep their finger on the glass or not. The player counting down from 3 then guesses how many players will be left. If that player guesses correctly, they will not have to drink all the drink in the glass. They are out.
This continues until there is only one player left. The last player remaining has to drink the entire glass.
For example if there are 6 players, the first player would say “3…2…1… 5 Players”. After that player counts down from 3, if there are 5 players with their fingers still on the glass he is out and doesn’t have to drink. If there is less than 5 then the player is still in the game and the next player guesses.