I'm trying to build a Dresden Files campaign set during the French Revolution (using the Dresden Files 2010 RPG rules).
First issue I had to solve was that wizards-technology incompatibility doesn't yet exist. I remember Butcher mentioned in one of the books that at some time period, wizards used to have problems with skin disease, so I went with that. (This also connected to Jean-Paul Marat, so it fit nicely with the setting.)
However, then I ran into a problem: in a Dresden campaign set in modern times, a Vanilla Human has access to guns, which even out the field quite a bit, and to cars (you can ram a monster with one), and to all kinds of other useful technology. French-revolution period guns were slow and imprecise compared to modern weapons, and while ability to use a sword was much more common, supernatural beings would have super-strength, or super-speed, or some such advantage making fights rather one-sided.
With that in mind, what advantage can I give humans in the 18th century, so they won't be drastically and painfully under-powered? I want to maintain "Mere Mortal" playable, without a player choosing it feeling like "the load" on the party.