If you underpay a foocubus (which includes not having any money in the first place), their chance of getting a severe headache is increased. This could even be implemented as a sliding scale where they are more likely to get a headache the more you underpay them by.

Artifact suit of armor (type is unspecified, perhaps a ring mail or chain mail) that is unaligned and operates like magic armor in the Legend of Zelda. When worn, it drains your gold at a constant rate, and when you take damage, you lose a somewhat randomized amount of gold, in exchange for partially or completely negating the damage (perhaps the easiest way to do this is via half physical damage, since it doesn’t make much sense for armor to protect against e.g. poison damage from drinking a potion of sickness). Gold is consumed at some rate higher than 1 per turn, and it is lost for damage at some rate higher than 1 per hit point.

If you have no gold while wearing it, you become either very slow or very encumbered, and it ceases to reduce or negate damage.

Croesus may occasionally generate wearing this armor, along with some gold to supply it. Otherwise it generates like any unaligned artifact.

When a leprechaun teleports after taking gold so they can bury it, if there is a leprechaun hall on the level, they will always pick a random unoccupied space in that room to teleport to. (If no space is unoccupied, they will teleport randomly as normal.)

Throwing gold into a fountain (by standing on it and throwing it downwards) makes the gold vanish, and has a (gold/1,000,000) chance of giving you a wish.

Enhance Minetown with a bunch of new NPC denizens:

• Dwarven trainer: found in a largish room.
  • Chatting to him makes him ask if you want to train, for a fee. If you say yes and pay it, he shouts “Defend yourself!” and begins to fight with you. This lasts until you chat with him again. While you are in this training fight, neither of you deal damage to the other one, though you can still deal damage normally to other things.
  • If you don’t want to train, he offers to teach you how to disarm for a large sum of money. Disarming is a technique you can use with the #disarm command after you have learned it from him. Possibly, it unlocks a “disarming” skill that you can’t get elsewhere. When you use the disarm command, you are prompted for a direction to pick an adjacent monster. The monster must be wielding a weapon, and you must have some minimum amount of skill in your weapon (which can be martial arts). The chance of success is 20% base, +1% per point of Luck (or -1% per negative Luck), +5% for every skill level above Unskilled you are in either your weapon skill, or the disarm skill, +2% per level you have over the monster, and -2% per level the monster has over you.
• Elven enchantress: Mutually exclusive with the trainer. Chatting with her prompts you for an item to enchant.
  • Items that are not naturally enchantable with enchant scrolls get refused.
  • Artifacts or items at their maximum enchantment get refused; she gives a line about how it is already surrounded by powerful magic and she dares not attempt it.
  • If the item is damaged, it gets repaired, for a modest amount of money per level of damage.
  • If the item is undamaged but not blessed, it gets blessed, charging a slightly higher amount of money.
  • If the item is blessed and undamaged, its enchantment is increased by 1, charging a larger amount of money that scales in direct proportion to the preexisting enchantment on that item.
  • She possibly fooproofs the item if it’s at maximum enchantment.
• Dwarven innkeeper: also found in a large room.
  • Chatting to him has him offer you an ale, for either 5 zorkmids or the appropriate buy cost of a potion of booze, and accepting produces the effects of an uncursed potion of booze, as well as identifying the potion of booze. 50% of the time, he also gives you a random rumor as if from an uncursed fortune cookie. (Criticism of this is that on-demand confusion makes several early-game challenges involving confused effects of scrolls trivial.)
  • He will also offer you a room to stay the night if the Watch is not angry at you, for either $50 or the cost of a potion of full healing. Accepting fully heals you (or produces the effects of an uncursed potion of full healing, without identifying the potion since one wasn’t involved). Not specified how it should deal with the time you are sleeping, whether that means literally putting you to sleep or something else.
• Old gladiator: found 1/3 of the time, possibly in the inn; chatting to him produces some old battle stories and a request for an ale (same price as if you were buying it yourself). The first time you buy him an ale, he will teach you a random weapon skill. Subsequent times he only thanks you drunkenly for the drink.
• Aged traveler: found 1/3 of the time, possibly in the inn, mutually exclusive with the gladiator; chatting to him has him offer to tell you the depth of the Oracle level for 50 zorkmids, or offer to “teach you some things he’s learned in his travels” for 1000 zorkmids, which acts like a blessed potion of gain level, but is not available after you get it once. Alternatively, he could teach you several random item identities.
• Dirty drunk: found 1/3 of the time, possibly in the inn, mutually exclusive with the gladiator and traveler.
• Bar brawler: found in the inn, interacting with him in any way will make him angry and start a fight. You’re allowed to fight but not kill him (which would anger the Watch), and you can pacify him by putting him to sleep, paying him off, beating him close enough to death to make him give up, or whatever. If the fight breaks out in the inn you owe the innkeeper money for broken furniture.
• Criminal or mugger: chatting to them makes them aware of you and they will try to steal from you later.
• Merchant: Wanders around Minetown, slightly weaker than a shopkeeper. Will sell you food rations at the standard price. Criticism of this is that an unlimited source of food rations is unbalancing and makes a delicatessen obsolete. To add balance, he might have a limited quantity of them to sell, but then he is still kind of pointless.
• Beggar: Has one randomly generated item, which he will sell at either its standard price or a discount. Most of the time this won’t be useful, but occasionally it could be something good.
• Bureaucrat: sits alone in a small room. Chatting with him makes him sneer at you, “I’m busy”. However, if the Watch is angry, he will offer to take a large amount of gold from you to pacify them.

A secondary proposal is to make some of the denizens who teach you things actually useless a random amount of the time. For instance, the gladiator is a liar who’s good at spinning stories and not much else, or the aged traveler is a charlatan who gives misinformation, abusing Wisdom or sapping your experience points.

Leprechauns should sometimes wake up when someone is moving near them carrying a large sum of gold. Their awareness doesn’t extend to the precise location of the creature, it’s just enough to shake them awake.

The chance of this happening and/or the distance at which this happens should be dependent on the amount of gold carried.

You should be able to use a forge to melt down gold items and turn them into gold pieces.

Pet dragons that eat mimic corpses should turn into large piles of gold, consistent with the stated reason that pets tend to mimic things they are thinking about.

The $ command lists, in addition to your currently carried gold, any amounts of store credit you currently have at shops you have visited.

Dragonhide gear naturally deteriorates gradually over time, and the only way to prevent this is to rub large quantities of gold on it, which destroys the gold.

A sentient and always-peaceful monster that you can recruit as a powerful steed, but you need to pay it a large amount of money to ride on it.

Vow of poverty as a conduct. It is broken by ever having money in inventory (with a grace period of a few turns at the beginning of the game for roles that start with money, or define the conduct as never having money enter the inventory so you can spend initial gold, or a roleplay option similar to nudist that prevents you from generating with any money).

New objects “scrolls of riches”, which serve as a means of storing large amounts of money without carrying around all the literal gold.

• Come in 3 types: “scroll of riches” worth $1000, “scroll of greater riches” worth $5000, “scroll of untold riches” worth $10000.
• Uncursed read effect: creates the scroll’s cost amount of gold on your square.
• Blessed read effect: as uncursed, but adds some extra gold.
• Cursed read effect: takes your money up to an amount between half the scroll’s cost and its full cost; if you lack enough gold it will start destroying your items in decreasing order of shop sale cost to cover the cost, excluding unique items.
• Confused read effect: either summon 1-3 gems (if blessed/uncursed) or glass (if cursed), or summon a gold golem as if from a figurine of the same beatitude of the scroll.
• Has an ink cost greater than 99, making it unwritable. Not specified whether it can be created from polymorph.
• Shopkeepers will always buy and sell noncursed scrolls of riches at face value, but will not buy cursed ones.
• If a guard sees you with a scroll of riches, they get angry.
• Several scrolls of untold riches appear in Fort Ludios.
• The thing that seems to be missing is a way to get these scrolls besides happening on them randomly; specifically a way to turn carried gold into them. Possibly shopkeepeers could generate with one or two and will trade them for the equivalent amount of gold.

The player is able to do some sort of ritual that involves sacrificing 25,000 gold pieces to open a portal to Fort Ludios if one has not already been generated. Possibly this would have to be done in a vault. If a naturally generated portal does already exist, the gold is still expended but the attempt to make another one fails.

New “pauper” conduct, in which you are not allowed to gain any gold pieces in your inventory (gold items like the gold ring and Candelabrum are fine, because they aren’t money).

An interesting side effect is that you can’t sell things in a shop since the shopkeeper will give you money directly for them, unless you manage to somehow remove all the shopkeeper’s gold, enabling you to sell and buy things for store credit.

You can magically charge up a credit card, which when you take it into a shop makes it good for a certain amount of store credit. Alternatively, applying a credit card with charges just spits out some zorkmids and uses up a charge.

“Dragon hoard” themed room: containing a big pile of gold scattered within a radius of 2-3 tiles around its center point, with larger stacks of gold closer to the center of the pile. The pile may also contain a few additional items: random gems, a ring or amulet, (if in an object-materials-implementing variant) a gold version of an item that is eligible to be gold. Atop the center of the pile is a dragon, or possibly a few adult dragons all of the same species, either asleep or flagged as waiting, with possibly a few dragon eggs of the same species and/or a couple baby dragons.

When you do something to anger the Minetown Watch, they become hostile but will demand that you pay a fine when they come face to face with you, and will only attack after you refuse or are unable to pay the fine.

If you approach a demon lord with a low amount of gold, they automatically become hostile.

Dragons that generate at level creation time also spawn a hoard of gold beneath them, similar to how concealing monsters generate items to hide beneath. Possibly, their AI recognizes the hoard as theirs and they are reluctant to stray off of it or far from it as long as there is gold there.

Rather than placing random amounts of gold on each tile in a special room that generates gold on each tile (zoo, leprechaun hall, and any other that might get added), bias it so that there is more gold in the corners and along the walls, on the basis that things tend to accumulate in the corners of rooms. Should work on irregularly shaped rooms as well as rectangular ones.

One possible algorithm is that corners get 3 “helpings” of gold placed on them, walls 2, and every other space 1.

Another take is to instead put more gold into the center of the room and less further out, possibly guaranteeing some dragons on top of the biggest piles.

Evil librarian monster: it is peaceful at first, but considers every spell you know to be an overdue library book, and charges you a $100 late fee per book when it encounters you. If you don’t pay, it attacks. Possibly they carry some books, and if you manage to keep it peaceful, you can loan books from it. May generate with a magic marker.

There is some ritual you can do that allows you to manually create the portal to Fort Ludios. It requires the sacrifice of at least 10000 zorkmids, possibly some special item that is only generated somewhere below Medusa, and that you be in a vault. If the portal to Ludios already generated, this will always fail (it won’t make a second portal).

New artifact short sword, which is the first sacrifice gift for Rogues. It does extra damage based on the amount of gold carried in your inventory (or possibly your opponent’s inventory, though this would make it no better than a normal short sword on many monsters). The damage bonus eventually runs into diminishing returns so that the damage bonus doesn’t get too ridiculous.

Gold that disappears by losing it in fountains, to thrones, or by failing to read spellbooks, appears in the Fort Ludios vault.

A magical bag which only holds gold and gems, but any gold and gems inside it don’t weigh anything.

Priest characters can sacrifice gold at a coaligned altar for identical benefits as they would get from donating to a priest. The altar does not have to be attended.

You can offer gold on a coaligned altar as well as giving it to a priest. This gives you a different, weaker, variety of benefits if there is no priest present (and the same ones if there is a priest present). When you do donate to a priest, they offer the gold themselves in a burst of light (which deletes the gold, preventing you from killing them or stealing to recoup it).

Gnomes get permanent detection of gold and gems within a radius 3. Or possibly the radius can scale with XL.

New role: the Debtor. You begin the game by having taken out massive loans to buy a lot of very nice (erodeproof, high enchantment, magical) equipment, and so you should be able to breeze through the first part of the game. However, from time to time, your creditors appear and demand large sums of gold as interest payments. If you can successfully find enough gold to comply with their demands exactly, your debt will never actually increase. If you can overpay, you will be paying off the initial loan amount, and hopefully will eventually pay it all off. However, if you cannot meet their demands, they will first disappear with threats and take any current gold you happen to have, then send repossession men to confiscate your equipment (they will sell it for far less than it’s actually worth and not really help to reduce your debt all that much), then send thugs to kill you.

The Mines have a higher rate of gold and gems embedded in rock than the other branches.

Gloves of fortune, which unlike SporkHack cause killed monsters to drop d10 gold pieces that didn’t previously exist, and rarely a gem.

Dowsing rod: chargeable magical tool that when applied tells you the total value of all gold and gems on the level that isn’t being carried by the player (but not their locations), and whether there are any artifacts on the level that are not carried by the player.

Rock moles and other item-eating monsters drop any gold or gems they have eaten (digesting them can’t be a fast process), or they destroy 10% of all gold they eat and have a 10% chance of destroying any other items they eat; otherwise those items will be placed in the mole’s inventory.

When a monster picks up an item owned by a shop, its base price is deducted from any gold they’re carrying and gets transferred to the shopkeeper. If they’re short on cash, they don’t have to make up the difference at all.

Soldiers and watchmen can be tamed by throwing gold at them. In order to make them tame, you must give them over a certain initial amount X, which will give 1 point of tameness, and giving them additional gold will increase tameness by 1 for every Y gold. Tameness steadily declines over time, removing Y gold from their inventory each time it drops by a point. Should tameness drop to zero, they become hostile. Chatting with them while tame will give you a clue about how tame they are: they will either talk about how they’re going to spend all their money, or wonder when the next payment is coming, or threaten you for more gold, depending on the amount of tameness. Normal magical taming methods do not work on them (as currently happens).

Dipping or dropping gold pieces in a fountain very rarely increases your Luck.

Reduce the amount of gold generated on the floor, and probably also that buried under the floor and in rock so it doesn’t incentivize the player digging out a level. This is an attempt at gold rebalance.

Gold generated from monster inventories should be tracked by the game and tail off after a while.

The Watch start with a small amount of gold, and will throw it at a player of the opposite gender while the player is disrobing.