From the introduction:
This is a planar supplement for Dungeon World, World of Dungeons, and other games of dungeon adventure. It is modular, so use the parts you like.
FERAL ANTHROPOLOGIES provides new GM guidelines for playing in settings where culture matters.
CORSAIRS AND LOW BRIGANDS describes the pervasive scourge of planar banditry and how to take part in it.
THE RAVENOUS CITY introduces the monstrous planar metropolis of Dis and its inhabitants.