At the start of each game both players pick odd or even. After a worm is damaged if the damage is odd, the person who picked odd takes a drink and vice versa.
If you hit a worm for more then 44 damage the other person takes 2 drinks
Any shot that plops (goes into the water) = 4 drinks
Self Own = 3 drinks
Sitter = 4 drinks
If you plop the other guys worm he drinks a full beer.
If you die, you drink 5 drinks.
Very very fun game. Had more fun playing this in a2b's with dilli then I've had in probably the last 10 years on this game.
It doesn't look like a lot of drinking but its quite enough

Please keep in mind when playing that in a standard bottle of beer there is roughly 12 drinks.