I'm pretty sure my carousing rules (reprinted below the break) are the most widely-used idea I've come up with here on the ol' Gameblog. If you use them or something similar, it might do you some good to think about what that gold spent actually buys you within the context of the campaign. Different campaigns will have different luxuries and debaucheries based upon differing economies and extent of trade. For example, in a game where gold flows freely and a thousand items are imported from across the world, that 100 to 600gp may buy you just enough Black Lotus Powder for the lone carouser to get blasted out of their skull for a single evening.
Looking at the Caves of Myrddin outings, set in fake Cornwall A.D. 1140, a carousing roll basically buys you a large multi-day feast/festival. Peasants from miles around bring buckets of ale, baskets of bread, armfuls of veggies, strings of fresh fish, and whole beasts poached off some lord's land. More than a few show up with live animals: chickens, pigs, sheep, etc. Some of this food is shared with the brothers of the abbey, as any food preparation beyond simple heating by the fireplace requires that it be sent to the abbey kitchens. Wagons bearing tuns of wine trundle their way across rough Cornish trails. Additionally, the guest house of the abbey is inundated by minstrels, jugglers, mimes, storytellers, dancers and other entertainers of various levels of skill.
Sometimes, but not always, stronger stuff than wine and ale are available. Merwik has a line on Welsh whiskey and can occasionally obtain aqua vita (brandy) from an alchemist. Sometimes a nearby halfling community will send a delegation carrying clay pipes and bundles of pipeweed. Apple cider and mead are available when in season. Maybe Dremelza the Witch shows up with her famous henbane homebrew. If it doesn't kill you it's quite a trip.
Extra candles must be procured for the late nights, as well as replacement furniture and dishes for whatever is broken. Occasionally a temporary stage needs to be built or a Maypole obtained. Ewella the Alewife and Merwik the Merchant try their best to manage these affairs, as it allows them to claim some portion of the money exchanged. In fact, they will happily act as go-between for a large portion of the affair, allowing them to claim even more of that 100 to 600gp.
Merry lads and lasses of several types attend these affairs. Outright prostitution is uncommon, but some of the travelling performers are subject to improved reaction rolls when showered with gifts, if you catch my drift. Ewella the Alewife tries to keep her kin away from the drunken embraces of the adventurers, but some of the country youths sneak into the party anyway. Some of these enthusiastic lads and lasses are 'adventure groupies' seeking secondhand excitement but some of the craftier ones are looking to marry up.
So carousing in Wessex is a public, community affair. The PC spending the money has a good time, but so do all the other adventurers in the vicinity as do many other people who crash the party (including a few brothers of the abbey who sneak out of there cells). Anyone carousing even once will be remembered by many in that hex of the overland map as a right worthy old so-and-so. Once the whole debauch peters out, most folks spend the next day attending Mass in the abbey church. Some do this to repent the various sins committed during the previous night(s), others just like to keep the abbot on their good side. Whatever of the 100 to 600gp is unspent by this point goes into the collection box.
Incidentally, the carnival nature of carousing in Wessex is the reason I feel free in blabbing adventure details whenever anyone uses the rules below. Everyone knows you got the gold for the feast from the dungeons. You're asked constantly to relate the tale of derring-do that resulted in your riches. You're already the life of the party, since you're paying for everything. You're drunk on God knows what. And this sweet young thing you've been chatting up is gazing at you with that look that tells you you're almost there. How many days in a row do you think you could resist bragging about your exploits under these circumstances?
Basic Carousing Rules: Spend d6 x 100gp to earn that many XP. The save versus Poison or roll on the Carousing Mishaps table below. If you roll more money than you have on hand you now owe the difference to some sort of criminal unless another PC can cover your expenses.
Carousing Mishaps (d20)
1) Make a fool of yourself in public. Gain no XP. Roll Charisma check or gain reputation in this town as a drunken lout.
2) Involved in random brawl. Roll Strength check or start adventure d3 hit points short.
3) Minor misunderstanding with local authorities. Roll Charisma check. Success indicates a fine of 2d6 x 25gp. Failure or (inability to pay fine) indicates d6 days in the pokey.
4) Romantic entanglement. Roll Wisdom check to avoid nuptials. Otherwise 1-3 scorned lover, 4-6 angered parents.
5) Gambling losses. Roll the dice as if you caroused again to see how much you lose. (No additional XP for the second carousing roll.)
6) Gain local reputation as the life of a party. Unless a Charisma check is failed, all future carousing in this burg costs double due to barflies and other parasites.
7) Insult local person of rank. A successful Charisma check indicates the personage is amenable to some sort of apology and reparations.
8) You couldn’t really see the rash in the candlelight. Roll Constitution check to avoid venereal disease.
9) New tattoo. 1-3 it’s actually pretty cool 4 it’s lame 5 it could have been badass, but something is goofed up or misspelled 6 it says something insulting, crude or stupid in an unknown language.
10) Beaten and robbed. Lose all your personal effects and reduced to half hit points.
11) Gambling binge. Lose all your gold, gems, jewelry. Roll Wisdom check for each magic item in your possession. Failure indicates it’s gone.
12) Hangover from hell. First day of adventuring is at -2 to-hit and saves. Casters must roll Int check with each spell to avoid mishap.
13) Target of lewd advances turns out to be a witch. Save versus polymorph or you’re literally a swine.
14) One of us! One of us! You’re not sure how it happened, but you’ve been initiated into some sort of secret society or weird cult. Did you really make out with an emu of was that just the drugs? Roll Int check to remember the signs and passes.
15) Invest all your spare cash (50% chance all gems and jewelry, too) in some smooth-tongued merchant’s scheme. 1-4 it’s bogus 5 it’s bogus and Johnny Law thinks you’re in on it 6 actual money making opportunity returns d% profits in 3d4 months.
16) Wake up stark naked in a random local temple. 1-3 the clerics are majorly pissed off 4-6 they smile and thank you for stopping by.
17) Major misunderstanding with local authorities. Imprisoned until fines and bribes totaling d6 x 1,000gp paid. All weapons, armor, and magic items confiscated.
18) Despite your best efforts, you fall head over heels for your latest dalliance. 75% chance your beloved is already married.
19) When in a drunken stupor you asked your god(s) to get you out of some stupid mess. Turns out they heard you! Now as repayment for saving your sorry ass, you’re under the effects of a quest spell.
20) The roof! The roof! The roof is on fire! Accidentally start a conflagration. Roll d6 twice. 1-2 burn down your favorite inn 3-4 some other den of ill repute is reduced to ash 5-6 a big chunk of town goes up in smoke. 1-2 no one knows it was you 3-4 your fellow carousers know you did it 5 someone else knows, perhaps a blackmailer 6 everybody knows.