Not too sure about this one, but it came to me recently.
You could kind of do it with a colonial-bent, i.e. there’s these colonies halfway across the world and back in the Old World everyone keeps to themselves and nobody much likes magic and there’s petty grudges and rivalries between all the different races and countries.
But in the Colonies everyone is forced to get along or starve. And the governments have all the guns, but the people have a lot of magic tricks and stuff.
And you can throw in a bunch of old ruins and dungeons easily enough.
I ran something kind of similar once – everyone was human and the colony was set up by an expansionist government formed after the fall of the Dark Lord / Lick King or something.
Then the colony started interacting with the outside world, who’d been staying as far away as possible from the Lick Kingdom for their own survival. And there were suddenly Elves and Orcs and Dwarves around, and the humans had no idea what was going on.
Wasn’t great, but it was the early 2000s.
Yeah, will have a longer think about this one.