Designate someone to be the dealer. The other two players must watch the dealer deal one card at a time face up for both players to see. When two cards are the same, the first person to slap their hand on the table and shout “snap” is the winner and the other player must take a drink.
The dealer decides who was first. If the same player wins three times in a row the other player must take a shot. When the Ace of spades comes up everyone must finish their drinks including the dealer. If one player wins 5 snaps in a row they get to make a rule for the game. e.g. No right hand drinking.