Since everybody is pitching in with a game suggestion, I'll add my own to the mix: I have not actually played a game in it yet, but I would suggest to take a look at Zweihander. It's a setting-agnostic spiritual successor to Warhammer Fantasy RP, ergo it lends itself to games where players are low-powered, filthy peasant fops who have to face soldiers, orcs, demons and worse while trying to avoid dying of disease or going insane. The system is quite dangerous, wounds are explicit, fights lethal. Magic exists, is dangerous and difficult to control, but is not mandatory and it is very easy to run mundane groups (even if they might face supernatural foes). And it is entirely contained in a single rule book.

In theory. As said, I haven't been able to try it, but I like its philosophy and ideas. The only downside is that there are, essentially, no modules/scenarios for it. There's one pre-made adventure in the rule book, and that's about it. You can convert Warhammer Fantasy modules to Zweihander rules, but beyond that you homebrew it or you're out of luck.