Level 0

Level 0 is most likely the first level you will encounter in the Backrooms.

Description
Apart from rare instances, Level 0 is repetitive, where it's nothing but the stink of old moist carpet, the madness of mono-yellow and the endless background noise of fluorescent lights at maximum hum-buzz. This level is estimated to be 1,000,000 square miles large.

Level 0 is mostly made up of randomly segmented rooms, but hallways, flights of stairs, and wide open areas can be found occasionally. Outlets scatter the walls, but most of them don't work. It is by far the safest level. Interactions with Beings in this region are rare, but can happen. The beings on this level are mostly humanoid in shape, but are very hostile. If you see one in this level, do not look at it. Turn around and walk out of the room the being appeared in.

Some people report the lights not being on when they arrive, but finding other rooms fairly close with working lights. The reason behind this is currently unknown.

Leaving Level 0
To leave Level 0, you'll need to spend some time there. After 4 days, Level 0 will fluidly progress into Level 1. You can also find a fire exit that can lead into Level 1.