How To Play:
Anyone can start. Do so by spinning a quarter on the table, then calling out another player's name. That player then has to flick the quarter at someone's bottle. If he hits the other person's bottle, that person must drink.   

However, you can guard your bottle by extending your pointer and pinky fingers, placing your pinky on its side on the table. You can move your hand anywhere around your bottle to block it, but you must keep your hand on the table and keep it no further than 1 inch away from your bottle.

Now, if the player who flicked the quarter missed the other person's bottle, the person whose bottle he missed can go (he spins the quarter and calls out someone's name). But, if he hit the other person's bottle, he must drink. The person who hit the bottle spins the quarter and the person whose bottle was hit drinks until the quarter stops spinning. The other players can keep the quarter spinning by tapping it, or just let it spin by itself.

Credit: Chaju