[tshiggins]

Here's a post-apocalyptic idea I've kicked around for awhile. The party members are humans who've grown up as the third or fourth generation in a Vault. Now, 100 years after the apocalypse, the Vault is running out of resources and nutritional deficiencies may soon start to appear, so the party is sent out to explore.

Pretty standard stuff, so far.

However, the apocalypse wasn't caused by nuclear holocaust, or anything, like that. Instead, dimensional breeches appeared and triggered EM pulses that caused serious damage to electronics of all sorts. Right after that, predatory beasts that resemble "the Dark," from Barbara Hambly's Darwath trilogy slipped through.

I'd make the "Dark" beasts a nocturnal (to the extent of taking damage from UV) hive-mind that uses chemical communications boosted by mild psionics. Each member is capable of taking on any one of several different shapes -- a flyer, a climber, a runner, and a pouncer -- any of whom can have barbed or clawed appendages.

It takes time and energy to shift forms, so most hive members segregate themselves out according to needed specialties, and they just remain in the initial shape chosen.

The species reproduces by fission, and any member will "bud" off a youngster, given access to sufficient nutrition. The ability to alter their forms, and plenty of redundant blood storage organs, combined with a robustly-competitive evolutionary history, means the Dark take limited damage from blunt trauma and puncture wounds (but cutting damage acts as normal, and UV results in serious burns), although sufficient force will kill them as efficiently as it does anything else (artillery always works).

The Dark eat animal proteins, and when few in number a hive is semi-nomadic, traveling at night, until it reaches a rich hunting ground. Then, it finds an underground lair and sets up shop, permanently.

Upon reaching a sufficient number, the collective IQ of the hive begins to increase, until the Dark achieve an order of sapience. At that point, they begin to herd and harvest human beings and other animals, as consistent and reliable food sources. They also become capable of recognizing and attacking communications, electrical and transportation infrastructure, so as to create isolated areas.

On the surface, the Vault explorers find small towns and villages inhabited by what appear to be regular people, living on the edges of old, ruined cities or amongst foothills. They suffer the usual sorts of raids and other problems common to post-apocalyptic settings, and are glad for any help. The people are always welcoming, and encourage the visitors to stay awhile -- even to the extent of offering the "hospitality" of young, eligible members of the community.

In essence, the villagers hope to increase genetic diversity and offer the visitors up to the next "cull," and in so doing spare the lives of their own elders. For their part, the Dark don't care who they get -- they need sufficient calories, and don't care where they come from.

The only people who are "free" in this setting are the raiders -- some of whom can be just as psychotic as anybody in a Mad Max movie. However, they know that to settle down and to try to build anything will attract the Dark, sooner or later, so they just keep moving.

What this has in common with a zombie apocalypse is that the greatest threat comes from the other survivors, and not necessarily the Dark. However, the Dark make for much more challenging adversaries than do zombies, when they do appear.

Alternatively, for a "doomed shoot-'em-up" campaign, back up the timeline and have the party be members of a military squad, or police unit, or set of first-responders, trying to deal with a natural disaster that has messed up electronic power and communications, while slowly becoming aware that inhuman things now rule the night.