Roll 1d7, modified by Luck!
1 or Less: Rot Gut literally rots your gut. Take 1d3 damage immediately, plus 1d3 damage each turn that you fail a DC 15 Fort save. Once you have saved once, the danger has passed.
2: Crypt Tequila forces a DC 15 Fort save. Failure means you drop like a stone, helpless and apparently dead for 1d6 hours. Your comrades probably loot your body.
3: Ghost Rum is tasty stuff! Succeed in a DC 15 Will save or take another drink - and roll 1d7 + Luck modifier again!
4: Manna Gin! Good for a +1d10 bonus on your next spell check, if you make it during the next 1d3 hours. After that, the buzz fades. Yes, multiple drinks can stack (if you are lucky enough). Yes, any class can make a spell check, so this might even help a warrior. Yes, McBones sometimes tends bar in dungeons!
5: Bone Brandy puts a stiffener in your skeleton. Your bones cannot be broken (for example, as the result of a fall or a critical hit) for the next 1d5 days.
6: Burial Bourbon heals 1d5 damage. Better, no matter how badly you are injured over the next 24 hours, you always survive (recover the body checks are always successful without a roll...of either type; if no one rolls the body, you awaken groggy with 1 hp after 1 hour). Even if swallowed whole, you are not slain, but receive a "free pass"!
7 or Better: Super-Whisky not only brings on a warm feeling in your gut, but heals 2d12 damage and all diseases! 50% chance of it being a double-malt that also neutralizes poisons!
McBones, Skeletal Bartender: Init +0; Atk claw +0 ranged (1d4); AC 9; HD 4d6; hp 13; MV 30’; Act 1d20; SP death throes; SV Fort +4, Ref +2, Will +6; AL N.
Death Throes: It is uncertain that McBones can be truly slain. Yes, if he reaches 0 hp, his bones are shattered, but as soon as that happens the house goes dry. Even water skins within 500' are mysteriously emptied. At the same time, somewhere else, a skeleton calling itself McBones opens the bar somewhere in the multiverse. Is it the same McBones? A successor? No one knows. McBones doesn't care to discuss the matter, and he never holds a grudge.