My players are starting to accumulate a little bit of gold. Upon what, dear reader, shall they spend it?
The TL;DR: Magic items borrowed, with a large cash security, from entrenched power groups.
As you can see, I’m plagiarizing^H^H^H^H noodling around with giving out parts of multiple magic items as treasure. Heart of flame, worth money towards this potion or time towards that scroll or makes a +1 sword flaming for 3 days. That sort of thing.
That requires large lists of treasurealikes to actually hand out. No good. Too much work.
Let’s work on something else for a sec.
The Duke is happy. He’s got a castle, a few badass men-at-arms who decided they’d rather get their treasure and magical items from the Duke’s pet artificers, who’ve got the blueprints and specialized forges to make +1 swords at below-market-rate, though they do need the brain of a treacher knight to quench the damn things cheap enough to make it worthwhile. He has the aforementioned artificers. He has the vaults in which the forges lurk. He has a small group of adventurers dedicated to putting down uncooperative bannermen, and he sends them out with chests of ice to bring the heads back.
In fact, due to this cycle, he has more swords than he knows what to do with. He can use them to secure leal servants and as gifts; he can give them to his second son and his favored gladiator. Sometimes these are gifts, but this is heavy munition; more frequently they’re loans used in pursuit of the Duke’s goals, or trades, or otherwise a financial transaction.
Let’s shift point of views. Let’s talk about the fighter for a band of adventurers. She’s doing pretty well. Killed a rust monster last week, lost her sword; she’s got her share of the Dragon King’s treasure burning a hole in her coinpurse. She needs a new sword, and the blacksmith won’t do. She wants a magic sword, but who just has a shop waiting for footloose adventurers to pop ’round?
Let’s introduce them. She knows the Duke probably has a laundry list of tasks he needs performed; she has loose coin. She wants to exchange the coin for a new quest for the party and some new trinkets.
She posts a bond equal to the sale price of the item, plus or minus whatever the Duke needs as a trustworthy quotient. The duke might ask 5x the sale price if he’s never heard of her and is playing 4e; he might ask 2x the sale price if she’s more trustworthy. He’ll give her a quest and, unusual in her line of work, the sword up front.
She can continue to wield it for as long as she’d like (and as long as the Duke doesn’t need it back, and as long as she doesn’t try to depose him — there’s a measure of control here, but realistically it’s not more than a local warlord with a band of thugs would’ve had organically), and when she’s done, she brings it back to the duke and swaps out. There’s some wear and tear on the blade, a matter of feudal obligation to consider, etc, but at the end of the day she gets a share of the original bond back (the “sale price”) and the Duke gets the sword back.
This isn’t necessarily a new system; the swords you’re finding in tombs that date back to ancient kingdoms had some form of this exchange occurring over them. Basically, this is feudalism in a nutshell, treating money as service and provision of arms as protection.
The Duke is probably not directly involved in these discussions; the Master at Arms is probably the one actually handling it; they’re in the Duke’s fortress and surrounded by guards, so the usual concerns about a “small defenseless shop” getting knocked over are somewhat lessened.
Okay, but that relies on a greedy medieval bastard going into sales. What if he doesn’t want to? Well, those pet artificers don’t grow on trees. Churches and universities and wizard guilds likely all have the necessary sorts of skill bases and facilities to run such an project. What they don’t necessarily have is the proper muscle. It’s perfectly reasonable to assume that the Invisible College keeps an Invisible Armory in their Invisible Fortress; they, too, operate on a lending basis with a massively overpriced bond to ensure the items come home some day. But the local church or hedge wizard probably doesn’t do this; instead, they keep a lot of raw materials on hand and are willing to craft whatever you want, but it’s bespoke and will take a week, as well as a quest to obtain a major missing ingredient. This stops the thief problem somewhat, though not entirely.
There’s probably a lot of work in retrieval, the old “go into the dungeon and take back the Flametongue sword that my loyal retainer got stabbed to death while wielding”. There’s also “so-and-so has turned treacher and needs to be stripped of their goods; reward equal to the treacher’s portion of the initial bond”. Where treacher is read as “kept something I wanted back”.