Sit in a circle, deal out the entire deck of cards evenly, or thereabouts, to each player.

The object of the game is to get rid of all your cards. Starting with aces, the first player lays down the number of aces s/he has, stating the number of cards. EVEN if the player doesn't have any of the card, LIE. 

If someone thinks that you are lying, they say "Bullshit!" If that person is right, you drink an amount proportional to the number of cards in the stack; lots of cards already played = lots of drinks.

However, if you were honest in your play and someone says "Bullshit!" that person ends up drinking the prescribed amount.

Play starts with aces, then goes on accordingly, through kings,then repeats back to aces.

Oh, by the way, if you have to drink because of either being caught bullshitting or falsely accusing, in addition to drinking, you must also pick up all of the cards already played and add them to your hand. 

Play continues until someone runs out of cards. If you so choose, play could continue down to the last two players.