Some Rules For Being Drunk Off Your Ass (Because Being Drunk Is Metal)

Adventurers are expected to be a hard-drinking, hard-partying lot, because how else would a bunch of glorious bastards get their R&R on after a long adventure killing awesome monsters and stealing treasure? With lusty wenches and alluring whores (of either gender, let's not discriminate amongst brothers and sisters in steel here) of course, but also with copious quantities of booze. Beer and ale are the most natural beverages, but sometimes you want to be classy and have some wine, or try one of those new and really powerful distilled beverages. 

The number of drinks you can have before it has mechanical effects are 2 + your Constitution modifier. If you're kind of a weakling and have a negative modifier, well, guess what, you can't hold shit. If you're a dwarf, half-orc or barbarian of any race, that two drinks is now four. You can make a Constitution save against poison to stop the effects of alcohol, but each drink after you start making saves makes for an additional -2 to the save. 

First drink: -1 to Intelligence, Wisdom and Dexterity. +1 to Strength, Constitution and Charisma. Arguably positive. 

Second drink: -2 to Intelligence, Wisdom and Dexterity. +2 to Strength, Constitution and +1 to Charisma. Worthwhile tradeoff for some. 

Third Drink: -3 to Int, Wis, Dex. +2 to Str, Con. 20% chance of confusion as spell effect. 

Fourth Drink: -4 to Int, Wis, Dex. +2 to Str, Con. 40% chance of confusion as spell effect. 

Fifth Drink: -5 to Int, Wis, Dex. +2 to Str, Con. 40% chance of confusion as spell effect. Con save to avoid passing out. 

Sixth Drink: -5 to Int, Wis, Dex. +1 to Str, Con. 40% chance of confusion as spell effect. Con save at -2 to avoid passing out. 

Subsequent Drinks: Str and Con go to +0. Penalty to saves to avoid passing out increase by -2. After the ninth drink, people who pass out must make a Con save against death. Every subsequent drink inflicts a -2 penalty to that save. 

Dying in your own puke might not be very heroic, but it is pretty metal. Ask Bon Scott.