I guess this would be a topic of concern given I have already mentioned firestorms over cities. Ideally that would be a level 100 character and not some level 20 bandit out in the woods. But beyond just balance, the question arises for me, how much magic? Where is magic in the world? How does it apply to the players? And equipment? And NPCs?
Basically only specific folks will get magic. Those being leaders, heroes, players, villains and dedicated NPCs.
Leaders are kings, generals and other distinguished leaders. A patrol captain probably wont have magic by default, but all distinguished leaders will have a form of magic, how else could a barbarian player really hope to compete with a mage in army on army combat?
Heroes, folks with the stuff of leaders, just they don't have the army. Same theory, possibly they don't like leading, suck at it or whatnot.
Players, assuming players find a way to not be one of the above two, their abilities would still classify to some degree as magical.
Villains, basically the opposite of heroes.
Dedicated NPCs. These would probably be the only casters without names, and shouldn't exactly be common in any but large armies and wealthy groups. That or just cloisters of mages and whatnot. They could take the form of a healer stationed with every platoon or a bunch of mages put together to salvo from a hill like artillery or something like that.
So I'm still considering how this plays out. As it stands now, I'm simply putting a margin in my max values for effects by gear on players. From a video game standpoint, it's basically, if a player only got the best gear of every kind to improve their intellect, this is what that bonus would be. If it goes down, I don't care, but I don't want it to go above that point, that amount is the maximum I think a player should get a bonus from items. I'm using a similar system for stats improvements and skills improvements. However, I'm not 100% at this point what those core maximums will be. I think they're going to end up in the 100s for sure.
Flying ships and automatons marauding around? Zombies in every graveyard and demons in every pentagram? Elixers of life and gods walking the realms? I don't think so. I mean demons and zombies, maybe, but I think the flying ships and automatons are out. I had a concept originally that each class would attract or create particular kinds of followers, but decided that was stupid. A charismatic person can attract any kinds of people, like minded or not they can still work well together. Of coarse my concept of mages summoning constructs to run their kingdom does go out the window with that one... For now. Early on at least, I intend for the main competition to be the other races and the occasional apocalypse beast.