The scarred fighter grimaces as she slides a gold piece across the bar to pay for the room. It actually costs 3 silver but, as she has no small change, she fears she will receive a pile of copper in return. 

The relationship between classic adventuring narratives and the coins in their characters' coinpurses is a long and storied one. After all, it is the need for coin (or debt) that underpins so many "why did you become an adventurer?" tables, plus there is the prospect of spending it on your domain/airship/carousing table. 

But here is a possible way to eliminate the minor purchases and associated bookkeeping, whilst keeping those "I'm never gonna financially recover from this" moments. 

Assumptions

• A character's primary source of income is treasure. (this may also be their source of XP, but it doesn't have to be)
• You are using some form of slot-based inventory system, ideally with some form of trade-off between filled slots and speed, hit protection, unwanted attention etc (note: this works with weight, but if you're willing to calculate and track that then coin abstraction may not be for you)
• There is an expectation of some amount of downtime in a settlement between adventures/dungeon delves.

The Rules

Treasure has two properties: slots (indicating the combination of weight, awkwardness, fragility etc) and worth (which may either be fixed for things in constant demand, or randomised for more fluctuating commodities).

• A porcelain vase depicting the Siege of Traban (slots: 2, worth: 1+d4)
• A sack of gold coins, mostly minted in the last 50 years (slots: 1, worth: 2)
• A complete collection of Lastent Military figurines, including the bagpiper (slots: 3, worth 2d6)

And so forth. 

When you spend time in a settlement, you have the opportunity to exchange treasure for goods and services. 

The cost of these in treasure is determined by the settlement's size. This also determines what is available there to trade for.

Roll for any treasure with a random worth, then pay treasure in upkeep according to the settlement's size (if you can't or won't pay, your status is insufficient to do anything more than gather rumours and slowly heal naturally) and for any services you use. 

If the worth of a piece of treasure is not fully spent, the GM can invent a new, less valuable treasure that has been received by the PC in barter/part exchange, however players should always be able to trade excess coin for more rumours about the world and status in the settlement.

Village

• Upkeep: 0
• Goods: Common
• Services: Rumours, Medicine, Carousing 

Special: Not many buyers - roll treasure worth at disadvantage when you spend time a village

Town

• Upkeep: 1
• Goods: Common, Uncommon
• Services: Rumours, Medicine, Carousing, Banking, Crafting  

City

• Upkeep: 2
• Goods: Common, Uncommon, Rare
• Services: Rumours, Medicine, Carousing, Banking, Crafting, Magic     

Special: Fast pace of life - downtime is halved in duration in a city. 

Buying Goods

Since most non-magical goods only cost a fraction of 1 worth, it is assumed that they are accounted for by the combination of time and upkeep cost and thus you can fill your inventory with them. However, note the following:

• You may only place items in your inventory which are available in the settlement
• The GM is free to apply a cost (even if it is wildly inflated) for items which are not normally found here 
• Players are free to spend treasure to obtain signature items, status symbols, build a relationship with a craftsperson etc

Examples of Goods by Availability

Common: Rope, torches, fresh rations, shovels, light weapons, arrows, waterskins

Uncommon: Leather or mail armour, a heavy weapon, lockpicks, 

Rare: Plate armour, Spyglass, illustrated book of plant life, clothing suitable for a royal court, 

Design Notes

The goals here are a) simplification but also b) generating interesting choices about *where* to go. A village is cheap for basic things - is getting that nice armour and identifying a magic item worth going to town for? There's probably some mapping guidance to be folded in here about villages typically being closer to the dungeon.

I think this procedure creates a world that feels a little more real - in the village you'll get by even with nothing (which is mechanically important if the party is robbed at low level for example) because if you spend long enough there we can assume you're doing manual labour or teaching kids to read in return for accommodation. Whereas the city will likely bar its gates to you.

Clearly, the costs and other details of the various downtime services need fleshing out - my intention would be to keep them to low numbers (1-5) to avoid too much treasure splitting (which risks creating coin by another name).

Side questions include whether to expand on the city fast pace of life and give each settlement a separate duration for what "1 downtime" consists of. Investing in settlements to increase their size is also an option.