Backrooms Mod

Backrooms Mod adds a new dimension, Level 0, that players reach through the End. Across the End, 19 handcrafted standalone Level 0 rooms generate isolated from other terrain, and Level 0 also appears naturally in the world as rare structure-based anomalies. The liminal structures are built to feel quiet and corrupt rather than loud, and the scripted horror and chase mechanics are meant to be found while exploring instead of announced.

Custom blocks recreate the classic Backrooms look, including yellow wallpaper, ceiling tiles, fluorescent lights and endless carpet, with carpet paired with slabs and stairs. Biohazard blocks apply the Wither effect to fluids, error blocks show visual anomalies, and a rare consumable called Almond Water is available. A sanity system tracks the player in the dimension, and a flashlight gives real light with a subtle flicker.

The mod is published for NeoForge only, for the single game version 1.21.1. It is distributed under the MIT License and is not open source. Installation needs NeoForge 1.21.1, and the environment is client and server, so the server and every player need it.