Board Thread:Roleplay Ideas/@comment-25606723-20160826001142/@comment-26084195-20160826184124

OK, well, it's kinda complicated, but I'll give it a shot.

"What if, all of a sudden, your friends and family weren’t themselves? And not just them, but your neighbors, coworkers – everyone. Even your pets. They still look like themselves, and even talk like themselves (except your pets, obviously)… mostly. But something’s off. That’s bad enough, but it gets so much worse. There’s something under their skin."

Somewhere in a still classified location in North America, archaeologists delved deeper than ever before, digging to a temple underground. A temple believed to predate Human civilization itself. So, curious as always, we Humans dug to find out what it was. And when we opened that ancient temple, we found that it wasn't empty.

A parasite. Of course, nobody knew that initially. The parasite started out small, and it could make use of all of a person's memories and abilities. They were almost invisible, and possession was almost immediate, spread through contact with a host's bodily fluids. They were totally undetectable. For a while at least.

See, slowly but surely the host's mind and body would be eaten away as the black slug-like parasite grew. Eventually they stop producing saliva, meaning that they have to infect hosts directly, and soon override their host's mind and no longer have access to their memories and abilities.

Even so, the parasite is shockingly resilient. You can riddle a host's body full of holes and the parasite will keep going. If you blow a body to bits the parasite will just possess a body part and crawl away. Get enough mistmatched body parts together and you form a colony creature, a massive blob of limbs and parasites that is nearly indestructible, and even if the military blows it up it just scatters limbs and parasites all over.

By the time the governments and militaries of the world realized what exactly was going on it was too late. Many of them had already been infected and driven into chaos, while military forces struggled to fight against an enemy that just wouldn't die! Civilization quickly collapsed in the face of the parasitic tidal wave.

Eventually, it's the survivalists, the ones who saw the danger and fled, that carry on the legacy of mankind, always trying to remain a step or two ahead of the hive-minded parasites. But even they will be hunted down and eliminated, unless something is done...

I also have a post-apocalypse scenario for this, with more intrigue than combat.