SPINNER CUP: This cup has a spinner built into the stem. Whosoever the spinner points to must drink from the cup. A game that is not entirely forgotten.
How would I rule a drinking game in an old school system? Each basic "drink" is 1 pint of beer or cider = 1 large glass of wine = double shot of distilled spirits.
Drinking skill doesn't match well with adventuring levels, so I would just use the ad hoc "tiny competence" system and have everyone roll a d6 (+2 if a dwarf, automatic 6 if an appropriate background such as "tavern keeper"). on a 1 you are a lightweight and must make two d20+CON >= 20 rolls after each drink, on a 2 you are a heavyweight and make one such roll after every two drinks, everyone else makes one roll per drink. Failure moves you one step down the track:
0: Not Drunk: You are fine.
1: Tipsy: -1 penalty to all rolls involving skill
2: Drunk: -2 penalty and -3 move
3: Legless: -5 penalty and -6 move. If you failed on a natural 10 or less, vomit, losing 1 drink from your system.
4: Unconscious. Recover in 2d4 hours.
Sleight of hand may be used to try to manipulate the die or the spinner, and the measure glass can be set as a d20 + WIS >= 20 task.