Fellow DMs and number-chrunchers, some time ago I attempted to estimate how much a small town would be able to spend on the service of adventurers. The entire calculation is based on lifestyle expenses and the wages given for workers of various skill levels in the Player's Handbook under "Services" and assumes a reasonable distribution of people from different societal positions in a town. Since permanent residents have a home and possibly a workshop or similar, a fraction of their income needs to go into the upkeep of these structures. In return, their lifestyle expenses are halfed compared to those of an adventurer who is always on the move. We'll further assume a 10% income tax as the primary source of income for the city and 30 days per month for ease of calculation. We are also neglecting holidays or weekends and simply assume that these are included in the averaged values used here. All individuals and the town itself will accumulate wealth in good times and loose gold during wartime or other times of trouble. We'll assume that anyone who is in their right mind and lives in a world as dangerous as DnD worlds tend to be will always have an emergency fund equal to 6 month's savings. Because you never know when the town will be raided by goblins/orcs/dragons/crazy necromancers/whatever and if that happens you want to have some coin for a quick escape or simply to buy food. On the other hand, once they have reached savings equal to five years of uninterrupted good times (which we know will never happen anyway in any DnD world) they will stop saving and instead begin a lavish, illustrous and expensive lifestyle full of bigottry which foreshadows the inevitable downfall of the town. Or well, they'll just enjoy themselves and wear fine clothes and invite their friends and relatives to nice partys to earn the second most important currency in DnD society after gold: prestige.

Let's start with the social classes that make up our sample town.

Now let's create a sample town. It carries the beautiful german name "Regenbald" (or "Rainsoon" if you prefer a literal translation into English).

Currently 4267 registered, tax-paying people live in Regenbald. We'll assume 4 persons per household and a single main breadwinner, which is a reasonable assumption considering large families with many children are the norm in Regenbald. This brings us to 1067 household, from which 35 people and their families are employed directly by the town. These 35 are not taxed by the town because, well, it wouldnt make much sense to tax the officials which you just paid with tax money. At least that's what the officials say... and the guard which is also paid directly by the town and exempt from taxation backs them up... so better stop asking questions now, citizen, will you?

Continued.

So, the City generates a profit of approximately 281 gp per month in wealthy peacetime and will accrue savings of 1686 gp – 16860 gp in its treasury and warehouses. Of course, not all this wealth is available in coin. A substantial portion will be grain, preserved food, and raw goods as a stockpile for times of trouble. Depending on the economic structure of the settlement, only 10% (isolated rural area) to 50% (city with well-established trading routes) of the wealth should be available in coins.

If the city enjoys several prosperous years, the city council will start to spend money and goods from the treasury on “luxury” buildings such as temples, enhanced fortifications, decorated places, wells and official buildings. The council will spend money on art, culture (music and theaters!), and festivities. This forms the main drain for the city treasury in good times – and the city will profit from it with a high reputation. Remember that in “medieval society” (and people in DnD essentially form a medieval society) everything is about social standing and prestige. A city that maintains a wealthy and respectable reputation for many years might attract more merchants from farther away, become the permanent seat of residence of a powerful noble house or attract revered guilds (magicians, alchemists, goldsmiths, banks) and one of the many influential religious cults in the world of DnD. You can either deduct actual values from the treasury or simply assume that 50% of the city’s surplus will be spent on luxuries once the treasury reaches 20% of its maximum (3372 gp in this case). This raises to 100% of the city’s surplus  spent on luxuries if the treasury ever reaches its cap (16860 gp in this case). Let us be honest though, given the numerous dangers and perils, this is not at likely scenario in any common DnD setting.

If conditions worsen (reduced trade, poor harvest, overlord war taxes, inefficient structures, diseases) the city income is reduced by 5/10/15% depending on the severity of the problems and the city will make a tiny profit of 189/96/5 gp per month.

In “difficult times” (famine, raiding parties of orcs/goblins/bandits roam the lands, the forest is cursed, dragons are around, …)  city income drops by 20/25/30% and the city will lose 88/181/273 gp per month. In consequence, the mayor will call for adventurers to solve the problems. City income will rarely drop by more than 20% (unless the city is a major trade hub or internal problems come on top) as most of the remaining production happens within the city itself.

During war time, the expenses for guards and fortifications double and the city will lose 454 gp per month, rapidly depleting its treasury and storages. If the city is under siege or the surrounding countryside is raided, it will suffer a 20% income loss on top, losing 542 gp per month. A well-prepared wealthy city can thus withstand a siege for roughly two and a half years without help or supplies from outside, while a poor city will endure it no more than 3 to 4 months and might surrender even earlier to preserve the last remaining supplies.

Thank you for this post. When my PC asks to become a town leader, they want to know how much it costs to run the town. This spreadsheet is very helpful. If a "town running cost" can be identified (e.g. 10,000GP per year), a PC is then more likely to consider continuing their adventuring and hire a town steward.