In my last post I had some notes on the challenges in the top levels of a campaign system. The other end of the spectrum are the bottom level atomic entities; those things on which, ultimately, everthing else operates.
There are some interesting puzzles here. For example does everything have a location? People would seem obviously to be in a place, but how about military units? Seem obvious but what about sub-components? Where is an 1870 French infantry regiment when its soldiers are sent their call-up notices?
How about money? One may speak of a wagon with the army pay-chest having a location, but if I am floating a bond issue in Paris where is the money then? Odd problems, without a single answer, and varying by period. But still important, if only in the decision to impose an unreal uniformity where in real life none existed (a process frequently confused with abstraction).
And how much do such things matter. The process of silver coin arriving at the army and the national debt increasing is a level of detail that the player should not have to worry about; we have agents for the Minister of War and the Minister of Finance, it's their job to work it out. But if we have no details of the model at all, how do we understand the effect of enemy action on the mechanisms? How do we know the rate the bonds will sell at, for example?
Correct design of bottom level detail will be important; it must have an adequate basic model to cover key issues across multiple periods. Interesting problem, probably best approached iteratively, starting with simple games that do leave big chunks out.