The backroom is an abandoned area within Doug 'n' Rachel's that the player must visit on Night 2 onward, (Night 1 in hard mode), to monitor The Thing's progress and prevent its escape by closing the mechanical red curtains in front of its tomb-shaped gift-box. In Hard Mode, it is the darkest area in the game (next to the off-line bathroom camera), and the player may need to shine the flashlight on the gift-box to see how long they have to pull the curtains closed.
The backroom appears to be a small theater-like room with mechanical curtains dividing it down the middle, opening slowly as if a show is occurring. On the side in front of them is only a dresser and a few props, while behind is The Things' gift-box and several ominous silhouettes of what appear to be vines and other out-of-place things. The gift-box's tall, thin, truncated shape is often compared to a coffin.
When you go inside the Backroom, the player will be prompted to hold Space to close the curtains on the first night. If the player does not do this frequently, The Thing will approach and end the game. However, in Normal Mode, The Thing's curtains stay shut all of Night One.
When the power fails, the player may run to the back and observe The Thing play music from its box and slowly open the box leave it, its arms and torso faintly visible sometimes as it does so, and other times only its head visible. This is the only time that more than its head is visible overall. The Thing will then jump-scare the player and end the night unless the player reaches 6 A.M. first. The Thing will take slightly longer to find the player if they are in the office instead, and slightly longer than that if they hide under the desk in the office.
- The curtains, and by extension The Thing, are supposedly inactive Night 1 of Normal Mode, but in fact can be seen moving very slightly on this night if the player leaves them alone for several hours. They may then pull them back if they choose to, but the curtains will never get anywhere close to opening.
- The backroom is the only area in the building that the player can enter but does not start in, is also the only major area outside the office without a camera, and lastly the only abandoned area.
- Since Phone Guy mentions the backroom being out of use, it is implied that The Thing is decommissioned.
- Rarely, the player may see small blue particles circling around near the floor after pulling the curtains all the way shut. It is unknown what these mean, or why they are even in the game.
- The Thing's jump-scares from inside this room are considerably different than from the office; it seems to actually be biting the guard in this case. The other animatronics will have similar jump-scares to how they attack when the player is facing the backroom, except shadowed due to the dim light.