SCP Foundation
The SCP Foundation is a writing site focusing on scientific descriptions of terrifying, confusing, or just plain weird monsters, events, locations, etc. Expect plenty of REDACTED all across the website. The community prioritizes quality writing over pretty much everything else, and as such it is THE place to go if you like top-tier horror fiction writing. The fucking huge critical community within will RIP'N'TEAR bad articles to pieces. (On the flip side, if you want to read some hilariously bad writing, go to the lowest-rated articles page. You will know the true meaning of stupid.) The SCP Foundation is primarily GRIMDARK, but there has been an appreciable trend toward a lighter tone in the community, if only to stave off apocalypse fatigue.
While the descriptions on the SCP Foundation website and the hinted-at setting loosely binding the different articles together are not directly related to any specific traditional games; the whole thing is a goldmine of ideas for your horror games from Delta Green to World of Darkness to Call of Cthulhu and everything in between; or even if you simply want to throw something weird at your players to deal with for a change.
Origins
The SCP Foundation started when the Creepypasta archive of 4chan eventually was inspected by a bunch of people, who imagined a worldwide conspiracy to suppress said creepypastas. Events like: "If you visit the ninth floor of the apartment at midnight, a spirit will assrape you and split your head open" *must be quarantined* for the good of the world at large. Said fictional organization would send agents to survey existence of supernatural phenomena, contain it if possible for safety purposes (and experimentation later), or destroy if deemed too dangerous.
It eventually shaped into a fictional wiki, where thousands of these "SCP"s (items, phenomena, or persons) are contained, by ludicrous force if necessary. Extensive descriptions and containment procedures are the most favored parts of the writings, as well as UTTERLY FUCKING TERRIBLE REALIZATIONS that your world is a clusterfuck of horror which out-edges Warhammer 40K on several metrics. For example, SCP-682 is an UTTERLY invincible creature that continuously attacks everything in existence because it enjoys things completely deadly and horrible to humans, and it can only barely be kept at bay via complete immersion in corrosive acid. There are also writings about the personnel within the Foundation, logs of fictional excursions to capture SCPs, and experiment logs to comb through. The first 999 SCPs are the first and best of the bunch, considered canon for all storymaking and combed over intensely. The wiki pushes lower-quality (and newer) works into later SCP enumerations, with SCP-1000 thru SCP-1999 (Series 2) being of secondary importance and canonicity to SCP-001 thru SCP-999 (Series 1), and so on with Series' 3 and 4.
And that's just the tip of the iceberg. One SCP is a genetic phenomena that makes the dreaming person's dreams real. That's right. Everything in reality, from World Wars to Empires is rewritten in one night's sleep. The Foundation's obvious response is to capture, detain, drug them into complete and total amnesia, use them once and kill them, and then authorize the genocide of "every population that may exhibit the phenomena." Another is Nikolai Tesla's Reverse Entropy Tesla Gun that will DESTROY EXISTENCE in a few decades, with NO WAY OF STOPPING IT. There's also a rock eating fish that eats California's seabed, slowly destroying one-half of United States, and the foundation failed to kill them.
And there are thousands more, and more to come.
Classification
Every SCP has a classification. It's basically a handy way of labeling them as to whether they have the power to totally assfuck you or not. Some of them may even have circumstantial benefits for you interacting with them, goodies like healing or granting you (usually abominable) powers. These classes are:
Primary Class
Typical shit. The initial labels given to any anomaly by the Foundation. Many of the SCP's still have these labels after a long time. We never said they were easy to neutralize, man.
- Safe: There is a good understanding about the object/entity, or it's easy to contain. Can still fuck people's asses if someone isn't careful with it. Think of it like a loaded gun: it's "safe" if you know what you're doing.
- Euclid: The object/entity is unpredictable and the Foundation has very little background on or understanding of it. They will totally fuck your asses, but it's an existential threat level that pales in comparison to the Keter below. Euclid entities might also be sentient, or may try to stab you in the back if you aren't careful, so they are generally locked behind many doors and walls of very thick metal.
- Keter: The good shit. OMFGYOUARESOFUCKINGDEADTHEWORLDISGONNAEND tier entity/object. They must be destroyed immediately, once the Foundation has found a way to actually do so. At the very minimum, they're
containedactively guarded from getting any worse by walls tougher than an Imperial Class Battlecruiser, protected by a non-national military host armed with future weapons and a legion of researchers, bureaucrats, and shadowy agents. These things, if they ever manage to breach containment, will inevitably make the world unlivable in one of innumerable horrible ways. Lucky for us, the Foundation has ways of mitigating these risks.
Secondary Class
Replacement labels for things re-classified from the Primary Class. Given to SCP's that the staff of the Foundation have a comprehensive understanding of.
- Neutralized: SCP entities/objects that are dead, destroyed, disabled, or otherwise no longer a threat. Often-times these were former Keter-class SCP's that the Foundation managed to dispose of. Their only remains are what can be gleaned from the heavily-edited documentation and records that the Foundation keeps. No one really wants to keep a doomsday device around, right?
- Explained: SCP entities/objects that can now be explained through science, or other semi-rational methods.
Esoteric Classes
The following Object Classes fall outside of the purview of standard classification.
- Thaumiel: Anomalous material or entities that can be used by the Foundation to contain or counteract the effects of other highly dangerous anomalies. Sometimes the best thing to do is fight fire with fire.
Famous SCPs
SCP-173: The Statue (AKA the Original) - A statue that kills you if you don't look at it. Started the whole thing, and yes, Whofags, it came before the Weeping Angels.
SCP-682: The Hard-to-Kill Lizard - A FUCKHUEG lizard that hates everything (except SCP-053, for some reason) and cannot be killed. There is a LONG list of attempts, none of them successful.
SCP-343: God - The (second?) most powerful reality bender in the world.
SCP-914: The Clockworks - A massive clockwork machine that has 5 settings: Rough, Coarse, 1:1, Fine, and Very Fine. Put something in the box, choose your setting, and pray the result isn't too radioactive.
SCP-239: The Witch Child - Similar to 343, but more GRIMDARK because it's a little girl.
SCP-055: [unknown] - The perfect anti-meme, something you can never remember. Wait - is there even a 55?
SCP-1974-EX: A d20 dice that gives players hallucination. Turns out the dice is covered in some kind of hallucination chemical. Never the less the article itself contain many references to /tg/ memes and related games, which is why it is listed here.
Drama
When you get a group of people to do something together, drama is inevitable. The SCP community has a number of big-names calling the shots, and what they say goes. They set the tone for what's allowed and what's not, and if you piss off the wrong person for a trivial thing or hurt someone's massive over-inflated ego, you can expect your stay on the website to be short. They are no stranger to massive internal strife either; fights between the big boys resulted in a lot of content being discarded at one point. It kind of mirrors TVTropes: the front end has a lot of nice reading but the community side is a dumpster fire of misery, egos and dicks. We do not prefer to give examples, but utterly retarded articles written by a newcomer cute girl may stay a lot while longer than they should (and any criticism thereof will result in a ban until someone with clout does something).
Early forms of SJWism have also started to surface, with articles spotting unusual genders without them being played for horror, or commented upon at all for that matter. Given a lot of SCPs are frequently not of this Earth/dimension/etc., there might be SOME reasoning for it, but unfortunately we're not that optimistic.