Exile: Escape From the Pit is the first game of the Exile Trilogy
. It's an RPG by Spiderweb Software
where your party (1-6 PCs) has been cast into a vast underground network of caverns for being different. There's an entire world in the caverns with other exiles and some not-so-nice monsters. Your goal is to escape to the surface.
Spiderweb Software later remade E1 into Avernum 1.