Easter Eggs are hidden surprises and inside jokes that can be found in Outlast.
Developer Names in the Game
Throughout the game, the player can find many appliances with the name "Morin" on them such as pens, heaters, refrigerators, televisions and prescription bottles. This is a reference to Philippe Morin, the co-founder of Red Barrels. The player can also find the name "Helman" on the computer screens. This is a reference to Jamie Helman, the senior animator of the game.
Falling Security Guard in the Elevator
At the beginning of Administration Block chapter, the player can walk up to the elevator, located in the middle of the hallway and trigger an optional event by pressing the elevator button, which will result in a screaming security guard falling down the elevator shaft to his death. This sequence was later included in the Xbox One version as an achievement for the game.
Blair Witch Project Reference
In the room, where the player can find the Project Paperclip Excerpt -document, there's another Variant facing a corner who kills Miles immediately if he comes too close. This is propably a reference to the ending scene of The Blair Witch Project.
I Am Legend Reference
Evil Dead 2 Chainsaw Outline
At the beginning of the Courtyard chapter, the player can go to the shack with the key in it. Using the camcorder's night vision, a chalk outline of a chainsaw can be found above the key. This is a reference to a scene from Evil Dead 2.
Red Barrels References
In the Underground Lab chapter, if the player zooms in on one of the emergency lights it will say "Red Barrels" on it, which is the name of the studio that made Outlast. If the player also looks closely at the blue barrels in the chapter, they will see that they say "This is not a red barrel" with the logo of Red Barrels Studio on them to oppose the cliché, as the studio never intended to feature any red barrels in Outlast.
Outlast Trailer Reference
In the beggining of the game right after Miles gets into the first room and the light goes out, the player can turn on the night vision of the camera and to their left there will be three pictures. If the player gets too close to the first picture, they can see Mount Massive from the first trailer of the game, where the player is pursued by Chris Walker.
Developers' Nationality References
Although most papers the player can find in the asylum are un-readable due to having a very low-resolution, there are a few of them that can be read, with most of them in french, possibly a reference to the developers' french-canadian nationality.