So my group is on a former hive world, where cities carved from the hearts of mountains were abandoned centuries ago for the open plains. They have managed to get inside one of these forgotten hives, but I am at a loss to describe it. I am familiar with hives presented in the books and in Necromunda, but those are all inhabited and thus not real conducive to exploration.

Obviously, it hasn't seen people in a long time - and there needs to be some event to have forced people out in the first place. How would you go about having them explore such a place? What would they see, where could they go?

Dead Men Walking, novel by Steve Lyons IRC

Describes the gruelling fight within a hive between Necrons and Death Korps after the hive is evacuated.

Cool descriptions of the different levels, skyways, floor level (which btw was flooded with waist-deep human dung), walls & gates, starport, etc.

Yet, if you are talking about Naduesh... I think that the hives there are a bit different. It seems that they look like giant IG fortresses with automated defense mechanisms (including anti-orbital).

Perhaps the reactor (or whatever) that powered the thing overloaded or just didn't work right and it flooded the whole place with radiation.

That would make the place sterile so bodies wouldn't decay and everything would be perfectly preserved (much to Nurgles chagrin) you could describe the air as dry and flat... somehow unsatisfying. You could also note the fully clothed bodies that look like a large portion of the population just went to sleep. They could have died five minutes ago but records say it was more than a thousand years.

Of course in 40K radiation doesn't just kill so somewhere in the lower (or upper levels) some corpses have been eaten and in the darkness there are sounds of movement.

After all if even 0.1% of a hive population was mutated and 10% of the population was killed by radiation before escaping and sealing up the city then the mutated ones could survive for quite some time on food supplies and corpses.

For descriptions perhaps go here: http://warhammer40k.wikia.com/wiki/Hive_City

I really like the idea of having rotting human filth amid the crumbling interiors of the hive, juxtaposed with baroque art and the perfectly preserved dead laying around - both are weird and otherworldly enough to make a massive abandoned city interesting.

Where I am really struggling is what sort of challenges they will find. They were more or less chased into an entrance of the hive, so maybe they try to find another way out? They find dangerous artifacts that endanger the planet and their comrades? A relic the Dark Eldar have been searching for?

Well the human filth wouldn't rot per-se as the organisms that cause decomposition would be killed by the radiation but if it was effluent and the like before the accident then it might potentially still stink in the sterile air.

I would make the challenges largely related to how difficult it is going to be to do anything in a hive that is unpowered. Lifts, doors, oxygen circulation, lights all those things need power so the explorers might find the lower levels filled with choking carbon dioxide(or worse) they will need to climb through slime and force doors open in pitch blackness.

Also throw in some areas of hard radiation that make sensors scream and Rogue Traders worry about being able to provide heirs.

Once they finally get used to the claustrophobic darkness and the unnerving lack of all other life forms then bring in some mutants or severed power conduits filling whole rooms with coruscating blasts of electricity.

If you want something to help describe an abandonned Hive, one suggestion I have is to really try and hit the feel that such a place invokes. The sense of grandeur lost, the emptiness of it all but also the feeling that you are treading on the bones of millions perhaps even billions. The players should feel small compared to their surroundings, so feel free to touch upon the sheer size of the interior of a Hive. Walls continuing up for hundreds of meters, the tops of spires hidden in clouds, the wrecks of ancient mag-trains, maybe add a statue that they walk across a ravine and then describe the fog-wreathed depths beneath them as they peer over the side.

Should you be using Roll20 or something similar, I highly recommend going for some background sounds, wind howling through streets, the muffled sounds of collapsing wals, pattering footsteps, etc.

If you're using a hollowed out mountain range as a hive city then you could always have tectonic activity be the reason it was hollowed out. Plates shift, stuff collapses or is moved, sulfur and magma flow cause problems, and the reactor is damaged. Thus, fearful of further earthquakes and with their home trying to kill them in various ways, they go to the planes, where the sky isn't actually going to fall on them if there's another quake.

If you want to play up the emptiness of the place I can think of a few things to say.

”After traveling for an hour or two you realize just how quiet and still it is down here. No hum of lighting, no people moving to and fro, no clank of machinery, or the rumble of circulation fans in their ducts. Even the air is still and stale.

This must be what it's like on a dead ship.

After seven hours of nothing but the noise you yourself make your nerves are getting frayed, and you find yourself starting at every miscellaneous creak and scuff. Conversation between the team died an awkward death in the suffocating stillness. Relief came when you heard the trickle of running water in the walls somewhere, but that is far behind and faded back into the dead stillness ages ago. You resist the urge to go back just so your can hear something that isn't your party.

One of your party (pick at random) insists that he keeps hearing scratching scuttling noises some distance behind you, but you're pretty sure he/she's just hearing things.”

Two movies that might give you some ideas for what an abandoned hive might be like are Pandorum and Mutant Chronicles.

Though Pandorum technically takes place on a damaged/drifting starship the environment always put me in mind of the underhive. May give you some ideas on...

- The sights, sounds & smells of a dying hive.

- Possible environmental hazards & obstacles.

- Mutants: Their dwellings and behaviors.

- Survivors: sane or scrofulous?

Mutant Chronicles can give you all of the above but a large part of it takes place in unpowered ruins underground, so may be better inspiration for a "dead" hive in the heart of a mountain.

First you need to decide why the hive was abandoned. Natural causes? An inquisitor, demagogue or psyker with the gift of the gab telling them to leave? The lava stream or thermal pocket that provided energy shifted, collapsed, changed position etc....?

Likely, there would have been panick, chaos. People fleeing the stricken city, people fighting to get away with their possessions, people fighting to steal those possessions. And naturally, there will be people who stayed behind. EIther people who didn't want to take their chances outside or people who couldn't leave (the lame, the blind etc.) and people who weren't welcome outside (the mutants, the criminals etc.).

And then there is the flora and fauna. Animals left behind, plants left behind. All without supervision. Many die but the hardiest survive and continue. One story by David Weber mentions a planet in which the ecology makes no sense at all. Until they discover that the people died out, leaving the biospheres with alien plants and animals (think zoo's etc.) to escape and eventually florish. And since every wh40k nobleman has exotic pets and weird plants....guess what?

So I don't think an abandoned hive is necessarily empty. It will be filled with the aftermath of a chaotic abandonment. Power will likely be out except for small enclaves of tech-savvy decendants of survivors. Wild animals have staked their territories. Feral, debased humans roam around fighting for resources. And plants grow everywhere, breaking up the rockcrete.

I ended up describing a handful of locations, and then coming up with flavor text to describe their journey in between the locations. Not sure the best way to "connect" the locations, in that I either lead them from one to the next or describe a couple being nearby and letting them choose. Obviously leaning towards the latter, but don't know the best way to make the "flow chart" all connect to each other in a way that suggests long travel times.

I would really emphasise long travel times between locations, unless its logical for them to be located close to each other. By long travel times, you push home the fact that moving about in an abandoned hive is not easy. Powered transport systems have decayed and are likely out of power, debris etc. slows travel down and then there are the dangers lurking in the shadows....And players will have to really finish their business in a location before moving on to the next. Going back is just too much of an effort.

I would also offer alternative travel methods, e.g. the players can travel from location A to location B by either traveling "above ground" or by climbing buildings and jumping from rooftop to rooftop or by using tunnels below ground.

Each has a very different vibe, each offers other likely encounters and opponents. And then let each player make a skill test of their choice to overcome likely challenges and encounters during the trip (kinda like an exploration challenge). If the total is DoS, then they reach their destination without an encounter or with some beneficial stuff they found along the way. If DoF, cue a combat encounter with a likely opponent (mutant rats in the tunnels, mutants above ground and mutant monkeys on the rooftops ).

We are playing Only War, so combat is usually the emphasis on all of our missions - I've been trying to change that, thus the hive exploration. There was only one instance of combat in the entire session, and that was them pumping las fire into a sump hole monster. I really played up the travel times, describing all the broken/nasty/rusty places they had to travel through to get to the next location, as well as all the perfectly preserved corpses.

Once they made it to a palace, I had some music come on that freaked everyone out and put them on edge. It was meant to be a exploration/skills-based session and it went well.