|You start by lining up (in order) one ace, one two, one three, etc, all the way to king (suit doesn't matter) face up on the table. Then one person is designated dealer. They get the rest of the cards, they then pull over the top card (making sure they are the only one to see it).
The first person to go then has to guess what card it is (not the suit just whether it's an ace, two, three, etc). If they guess correctly on the first try they become dealer and the current dealer has to drink 5 (sips, chugs, seconds, doesn't matter, you decide this at the beginning).
If the person guesses incorrectly they have one more chance to guess right. Before this guess the dealer has to tell them whether the card they are holding has a bigger or smaller face value (aces are low by the way). A correct guess and the guesser has to drink 2 and becomes dealer, dealer drinks 5.
An incorrect guess means the guesser has to count how far they were from the actual card from their guess and drink that many (eg. if the dealer had a king and the guess was a 9 then the guesser would have to take 4 drinks).
It's now the next person's turn to guess (dealer stays the same if they are not beaten). The card that was just held by the dealer the previous round goes behind the corresponding card that is already on the table.
This is a great game, the closer you get to the end of the deck the more times the dealer is beaten due to process of elimination because there are few cards left to guesss from. Which means 5 drinks every time it switches for the dealer. It's best to play with at least 3 or 4 people minimum. Have fun.