I want to run a campaign in which the players control individual but influential characters (maybe heads of families), with the main focus of play on the PCs building up a city over time, starting from its founding as a village. I plan to do this over voice chat or a play-by-post forum. What I'm missing and need is a rules system to manage how they gather resources, money, workforce and all that; how to spend that on buildings and improvements to build a village, and how to track their progress as they keep growing it until it becomes a city.
When it comes to the geography of the area, history, conflict – everything story related – I have it covered. But the focus of the game is less on that, and more on the challenges of having to gain power and prestige through either gathering wealth from their economic endeavors, or through other means such as politics, military or thievery.
What I need and I lack knowledge in, is how to handle that? I want to start them off with a basic village, nothing built but some hovels, and have them go from there. But how do I assess the cost of buildings (such us houses, carpentry, mills, farms, mines, bow makers, etc.)? Or how many people would it take to run them? How much profit or goods would these buildings provide the players? How do I tell when the village has turned into a town – what are the requirements to achieve that? What goods and necessities do the population have and need fulfilled?
I have no idea where to start, how to pick value of resources or buildings. Is there a system for this? A rulebook? I have yet to come cross anything that can give me details on how to manage resources, population, production, building, etc. for this kind of game.
I'm specifically looking for a system that deals with that level of detail and simulation, not one that abstracts away the details.