Backrooms drops your players into the yellow rooms behind reality. They wake up on Level 0 with a dented flashlight and one battery, and from there it is a run: search the rooms for supplies, keep their head together, stay quiet, climb into a locker when something comes, and find a door. Some doors lead deeper, some lead home with a cash reward — and some are traps.
Every run is a private copy of the world shared by up to four survivors. Five levels each have their own light, sound and monster, and an AI director watches how frightened and how loud the group is to decide when the lights die, when something starts walking, and when to leave them alone. Players get in by dying — a small chance of waking up inside instead of at the hospital — through entrances you place in the world, or by being sent by an admin or another script.
Almost nothing is configured in files. Language, rewards, survival, the HUD, restrictions and access are settings changed live from an in-game panel, entrances are placed in game with a creator, and every run is recorded for an in-game statistics window.