So I got bored and did a thing and made a "budget" thing. I just drew a quick thing up to do a basic economy thing; not hard to use in an NRP if you're willing to do some numbers. If it looks familiar, its probably because I'm jacking EU4's thing just a little. Don't worry though, the math behind it is just addition and subtraction so no wonky percents or anything.

Do note that this is based entirely on a turn-based system and that everything is just mucking about at this point and may not be universally applicable. All "prices" would be determined by the GM for the RP if they use the this.

[url=https://docs.google.com/spreadsheets/d/1C0-mUQMMFNWzaJ2-DqfptSdipUU9nLDN3NKbgwPqUHQ/edit?usp=sharing]Click Here for the thing[/url]

[hider=short explanations of what each thing would do]
The Land Tax would be how much you get from each amount of land wether that be in tiles/hex/km[sup]2[/sup] or what not, basically a national tax. The Land Upkeep would be how much you have to pay for the land in terms of infrastructure and what have, probably be like... 50% of the the Land Tax (just using 50% as an easy example number).

Production is basically how much your industry makes and split between civilian and military, I shouldn't have to explain what those are. Trade Goods is something I took out of EU4 and basically the worth of whatever special resource you have or something and may not be universally applicable. Trade deals is basically you agree to have a special trade deal like you see in Total War with someone and it gives X amount of money to both sides.

Tribute, Reparations and Looting are some what self explanatory to anyone whose played EU4 or the like. Tribute is basically any money you get from a subject nations (ie: vassal or colony). Reparations is straight from EU4 with the looser of a war having to pay the victor a set amount/percent each turn if the victor decides to press it. Looting is basically you have an army, its sitting on a piece of enemy land and you get the Land Tax for "looting" it each turn instead of the enemy.

Military Upkeep is again, simple; X number of troops/ships will cost Y amount to maintain and each major fortification would require a certain amount to keep running and stocked. The Diplomatic on the Expense side is the reverse of the Diplo on the Income side. This is where your tributes/reparations would go if you are the ones giving them.
[/hider]

So yeah, [@Polybius] maybe you could use this as some sort of basis for the economics of the system or something? I just got bored and interested and spun this out so yeah, its not exactly very deep but nor is it complex to understand. If you really wanted to add dice rolls to it you could have it so that each turn you roll a d10 or something and on a 4-7 nothing happens, on a 1-3 the total goes down respectively (3 would be 90%, 2 is 80%, 1 is 70%) or something and on a 8-10 the inverse would happen. I don't think that's possible to do google sheets tho.