Take one can of beer and put in the middle of the table.

Spread the cards in a cirlce around the can

 the first person takes one card from the circle

the second person also takes one card from the circle

the person who has the lower of the 2 cards drinks the difference

then the first person puts their card on top of the can with a minimum of 2 corners off the edge

keep going around until the cards or gone

whoever knocks the fan off the can has to shotgun the can