For the GMs knowledgeable about the Dark Heresy material.

My next campaign was going to take place around the Malfi-Landunder-Lathes area of the Calixis sector. I'm having a bit of a problem wrapping my head around the description / concept of Landunder:

"Upturned world. The limp, untrustworthy planetary crust floats free on a vast, chemical ocean. The colonies here are built to cling underneath the planetary crustin suspention. Eight "hanging" undercities, containing almost a billion inhabitants, with trade deriving from ocean-depth mining and chemical treatment (processing plants exploit the curious mix of oceanic chemicals)."

So... questions about that: the planet is mostly composed of a liquid chemical ocean, correct? Various mineral flotsam collects together to form continents and the cities hang underneath these landmasses collecting and refining the chemicals as well as journeying down to the actual crust to mine? It sounds like a cool concept if I have it right.

Thats more or less correct as far as I can tell.

If you want an additional planet without much work I wrote a second habitable planet in the Landunder system for my DH campaign. I've posted it up under my thread over on the DH boards.

Thanks Ill have to check it out.

One thing to keep in mind when designing NPCs from Landuner: They are known for skillful and brutal bladework on this world. Not the stately and refined fencing of Imperial nobility, but rather the chaotic desperate whirl of a ghetto knife-fight. This is a byproduct of strict discouragement of firearms on their world for reasons that should be pretty obvious. Will every adept have WS40 and swift attack? Nope! But some of the local bully-boys might...

My players visited Landunder to blackmail a judge on orders of their inquisitor. They hated the planet intensely when they were told they couldn't take their guns in with them.

As for the place itself, its a rocky core, covered with vast chemical oceans covered with a thin rock crust. The hives hang like barnacles from the bottom of this rocky crust (it maybe thin planetary speaking, its still several miles deep). The hives don't move or go down to the crust, the crust is above the oceans and the hives hang from it.

I imagine massively reinforced submarines, vast chemical refinement pants, arbites armed with webbers rather than shotguns, and evry now and then some catastrphic disaster when a hive breaks loose from its moorings (terrorism, badly maintained equipment, war, etc) and plummets towards the core, slowly being crushed and ruptured as the pressure wrecks it.

Its an interesting world to set stuff. Quite different from anywhere else.