marianlh's post about
the cutest little rust monster reminded me of the webcomic
Dark Places and how sad I was that by the time I had discovered it, it had stopped updating. Late in its run, though, there was an expository page that really caught my attention:
That comic really got my imagination firing, combined with Exalted setting elements and some concepts from the
Avernum series of games, and it mixed into (I like to think) a great campaign pitch.
So, take that comic as the backstory, but replace the dwarves with the Mountain Folk (with artisans removed). The Fair Folk are obviously the Fair Folk from Exalted, who swept in from Faerie, threw down the kingdoms of men, and reigned in madness from their thrones of bone and crystal and shadows until they were overthrown. Subsequently, humanity grew more and more xenophobic and paranoid, eventually developing into the Empire from Avernum. With the discovery of the great caves far below the surface of the world, below even the furthest reaches that the Mountain Folk dare to go, the Empire had a place to dump its malcontents, its Faerie cultists, its political dissidents, and anyone else that the Imperial power structure thought were a threat to the survival of humanity. Player characters being notorious malcontents and threats, the game would start with them being dumped through the portal into Avernum.
PCs would be god- and elemental-blooded (descended from various spirits), fae-blooded (descended from the Lords of Madness and their human slaves), ghost-blooded, demon-blooded, and Mountain Folk exiles, who are exactly the kind of people who wouldn't fit in on the topside unless they slot into some highly-specific roles in society that suitable PCs probably don't come from. Put them down in Avernum, which has the standard D&D-esque paradigm of a society on the edge, with civilization as precarious points of light in the midst of a vast, unexplored wilderness filled with dangerous monsters and mysterious terrain, and let the adventures roll in.