r/DungeonMasters • u/josue804 • 11h ago
Resource I built a tool to stress-test fantasy economies and turn them into shops your players can browse
About six months ago I came up with this idea that it would be really cool if a fantasy economy I was building could actually feel a bit more alive.
Like, if a dragon takes over the main iron mine for a region, what happens?
Iron gets more expensive, of course. But then how does that translate to steel, swords, armor, tools, etc?
And what if one town is under siege while another one has plenty of supplies?
Instead of making a giant spreadsheet to keep track of all of that, I thought it would be fun to turn the idea into an app.
That eventually became this app I've built called World Pricebook.
You can define how things in your world are made using materials, crafting recipes, and labour, then change something in the world and see those effects work their way through the economy.
So if you have:
iron ore → iron ingot → steel → longsword
and something happens to the supply or price of iron, the things that depend on it react too.
The first screenshot is an example of that with Mithril Chainmail. It takes 8 Mithril Ingots and 10 hours of smithing directly, but once you follow the ingredients further upstream, the whole production chain represents 322 hours of labour.
The part I think could be especially fun for DMs
You can take that economy and build actual shops from it.
Shops can have their own inventory, pricing, and local conditions. You can customise the storefront too, then share it directly with your players.
The second screenshot is one of those player-facing shops.
So a blacksmith in a mining town and a weapons merchant in a city under siege can actually behave like they're in two different places, rather than just having the same equipment list with the same prices.
There's a 5e-compatible starter if you want to mess around with an existing economy instead of building one from scratch, plus basic fantasy and sci-fi starters.
It isn't limited to fantasy either. The underlying system can be used for pretty much any made-up economy.
You can explore the starters without creating an account:
It's free during the launch preview. Right now I'm mostly trying to get it in front of actual DMs and see whether people find the whole living-economy idea useful.
Small transparency note: some of the prototype storefront artwork is AI-generated. If people actually use this and the project turns into something with a future, I'd much rather commission an artist to replace it.
If anyone tries it with their campaign, I'd genuinely love to know what you end up doing with it, especially anything that makes you go "wait, that price makes absolutely no sense" 😂