Beneath the city where the humans dwell is an empire. The ratfolk as they call themselves, although humans merely refer to them as vermin, are anthropomorphic rat-like creatures with voracious appetites and quick reflexes. Small in stature, only about three or four feet, the ratfolk make up for their lack of size and physical strength with sheer numbers and unwavering tenacity. They live in the vast sewerage system beneath the human city and survive by sending out raiding and foraging parties to the surface under the cover of darkness. Any that are discovered by the city guards are slaughtered without mercy, as they are seen as nothing but a plague on the city. But the ratfolk are a determined race. Able to reproduce very rapidly, they can replace their dead in a hurry and continue to eek out the best existence they can in spite of the humans above making every effort to exterminate them. Sometimes, the humans even send down parties of hunters to kill them in the sewers.
Although the ratfolk generally can only hope to scavenge and steal in order to survive, there are rare times when food is plentiful and the humans are lazy in their culling of their numbers that the ratfolk colony swells to the point where they can attempt huge raids on the city, pouring forth from the sewers to strike back at their above ground tormentors in all-out war in an attempt to take the city for their own.
So that's it. Basically this is a medieval fantasy setting, although I'd be open to discussing making it a steampunk setting instead if that sounds more interesting, where we play as the ratfolk, living beneath a large city in the vast sewer system. We forage, raid, and just try to survive. We're basically the Skaven from warhammer without being completely evil.
Let me know below if you're interested or if you have any questions, comments or suggestions. I'm sure there's something that I forgot to add or explain. Also, I haven't GM'd anything on here before, so if anyone wants to help out by being a co-GM that would actually be really appreciated. So just gauging interest here. Once I know if anyone is interested, I'll go ahead and make a thread for the IC and OOC as well as a character sheet. Thanks!