"When I said "deadly neurotoxin", the "deadly" was in massive sarcasm quotes. I could take a bath in this stuff. Put it on cereal, rub it right into my eyes. Honestly, it's not deadly at all… to me. You, on the other hand, are going to find its deadliness a lot less funny."
-GLaDOS (Portal)
All of this is of course are not real and/or not confirmed to be really made by the developer that way, but is fascinating to read.. and disturbing. Here's your creepy fan theories that are make sense and pretty good creepypastas about games.
Fallout: New Vegas
Lone Wolf Radio Killing Children Live
Among the several radio stations in Fallout games, there is one that bear a sinister story within. The Lone Wolf Radio, located on the south of Goodsprings there is an abandoned trailer that the Courier could visit. Inside you'll see a bunch of radio station equipments, nothing so special but the Wasteland Survival Guide and the Sunset Sarsaparilla star cap.
But, a fan made a creepypasta out of it and make it more than just an abandoned trailer, Lone Wolf Radio. It says that there was supposed to be a quest called Little Dead Riding Hood where the Lone Wolf would bring a children every 3 a.m. For what you ask? For him to viciously murder live on the station right after The Lone Wolf announce "Everyone is gone. You are all alone. Let it all end."
If the Courier tune to the Lone Wolf radio at 3 a.m. the quest would trigger and s/he will have to find the Lone Wolf to either stop him or join his child-killing radio broadcast that will unlock a perk that let the player to kill children in the game.
Well this is creepy, and apparently many people like it so much that they asked for a mod of this.
Portal
There Are People Inside the Companion Cube
Who would have thought that one of the most beloved and memorable... characters(?) holds a dark secret behind that pink heart? So there's a fan theory that says the Companion Cube contain people inside it, failed GLaDOS' test subjects that are unknown if they are dead or incapacitated.
What makes it more creepy, is that there are easy to miss secrets behind GLaDOS' "jokes" (or not jokes), such as when GLaDOS remind you twice that the Companion Cube cannot talk, and if it does you should ignore it. However, Ratman say otherwise; "The Weighted Companion Cube does speak." followed with "I'm not halucinating. You are." written on the wall in his first chamber along with another hints; photos of people with their faces covered with Companion Cubes.
So the Companion Cubes are possibly filled with Ratman's coworkers, test subjects who failed and then shoved into the Cubes. If you think that's enough, there are more convincing things about this theories.
The Sims 3
Sinister Background of a Happy Family
What could a life simulation game like The Sims 3 have in it to creep you out? The answer is the Doe household. John and Jane Doe is a perfectly happy married couple with three kids, Joseph, Jennifer, and James Doe.
When you think of it, this particular family is kind of suspicious and creepy already because first, the Doe family live in Midnight Hollow, a spooky rarely sunny place where you might as well find Shelob if she exist in The Sims universe.
Second, according to the wiki the names "John Doe" and "Jane Doe" are used as placeholder for those whose true identity is unknown. To make it even creepier, the names are also used to tag a corpse or a hospital patient with unknown identity.
Is that all? No. The last, is the household's description;
Nothing mysterious seems to be happening here, but didn't their house used to have a basement?
Did John buried his basement where he throw his victims in? And the fact that it says nothing mysterious seems to be happening is making it mysterious. To make it more convincing that Doe family have a sinister past, check out this community blog by one of The Sims 3 producers.
The Elder Scrolls III: Morrowind
Horror Mod
I'm not sure if this one is a mod or a creepypasta, but what I'm pretty damn sure is that this is creepy as hell. Probably more scary than all the scary stuff from the game. According to the Creepypasta Wiki, there is a mod that could drive the player insane called Jvk1166z.esp that were not posted on large Elder Scrolls communities, only on smaller RPG groups and/or through email to those who are lucky.
For some reason the mod will only work if you run Morrowind with DOSbox. When the game start, thing you'll find is that every main characters are dead and their bodies will never despawn. Your HP will also depleting little by little if you keep standing in one place and when you finally die, you'll find out that you are being "eaten" the whole time without you knowing by an unsettling black inhumanly crawling figure known as the Assassin, because he seems to be wearing a Dark Brotherhood armour from Tribunal.
And if you pay close attention, you could see the Assassin around a corner or crawling up a wall for a brief moment. What make it more creepy is that every night the NPCs would go outside and say nothing but "Watch the sky.".
Fun Fact:
Wheatley went into space in real life too. A NASA staff laser etched Wheatley on to the part of Japanese Aerospace Exploration Agency’s H-II Transfer Vehicle, with the line "In spaaaaaaace!" under it.
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