On some level, this might actually be getting closer to RPGs’ roots: I want to try a campaign where the PCs are members of a larger military. There may be need for them to coordinate with other units on a larger campaign, or bail allies out, and so on, but I want to avoid some problems I see with this:
The players should still (at least eventually) feel like the stars of the story, despite the important things that may also be going on around them.
They should come to be leaders/champions of this army, but I don’t think my players are necessarily interested in really doing much in the way of general-ing (and I’m not particularly interested in it either). Basically, I don’t want it to turn into a war game (though ultimately if that’s what the players want, that’s what the players want).
I think there should be some level of unpredictability in what other units are able to accomplish, both because it’s more interesting and because it eliminates any possibility of their successes/failures being perceived as railroading.
I’m envisioning a fairly-epic quest from low levels to high. The players will start as fresh graduates from a military academy, and by the end of the campaign may be fighting off demons for the sake of the world. I need suggestions on how to handle their allies’ growth or lack thereof alongside them.
This is not necessarily a system recommendation question, but I am quite interested in systems and books which have established rules for handling this kind of thing, if only for comparison/consideration. Basically, I need extremely streamlined ways of determining what these other units are doing and also how to communicate what they’re doing to the players.
And while this may or may not involve a system recommendation, all “shopping” questions like this go under the usual guidelines for Good Subjective, Bad Subjective, and I think the usual blurb about system-recommendation should be applied here:
As this is a system-recommendation question, please adhere to both the FAQ and the rules for subjective questions as outlined in Good Subjective, Bad Subjective and on our Meta. In particular, all responses should be based on actual experience and contain references and examples whenever possible.
It may (or may not) be relevant to your answer that the intended setting is fairly typical fantasy, with reasonably high magic. Mages might be fairly rare among the common folk, but then so are knights, and your local priest probably can manage a little. The army, of course, has mages as a major component of most units, as support and artillery behind the warriors.
This need not actually change your answer though. If you have useful information for a more sci-fi setting or modern setting, I can certainly use that.