Level 0 of the Backrooms is a sprawling, unsettling expanse resembling the faded, neglected back rooms of a long-abandoned retail store. Its signature yellowed wallpaper peels subtly beneath inconsistent fluorescent lighting that casts a harsh, sterile glow on damp, threadbare carpeting, while scattered electrical outlets hang sporadically from walls that shift in unexpected ways. Though each room shares these surface details, the spatial geometry is deeply non-Euclidean—walking in what feels like a straight line can bring you back to a completely different set of rooms than before, twisting time and space into a maddening, looping labyrinth. This distortion, combined with the overwhelming monotony and lack of resources, quickly saps wanderers’ resolve and health, making dehydration, starvation, and exhaustion the primary threats in this silent, hostile void.

The constant, buzzing hum from the ceiling lights permeates the entire level, far louder and more invasive than normal fluorescent fixtures, often inducing persistent migraines that linger long after escape. This relentless sensory assault, paired with the confounding spatial anomalies, leads many explorers to experience vivid auditory and visual hallucinations, and in extreme cases, a complete mental breakdown into “utter lunacy.” Above the low drop ceilings lies a cramped, dusty crawlspace filled with tangled wires, ventilation ducts, and rusted fixtures, but the thick dust makes the air nearly unbreathable and the area mostly inaccessible.

Adding to the eerie atmosphere are the lurking entities formed from rampant bacterial growths that appear as shifting, fleshy pools creeping along floors and walls. These Bacteria Monsters evolve through stages—from thin, slime-like films to thick, viscous mats pulsing with faint bioluminescence. Among the most feared is the Hound, a towering, twisted figure over eight feet tall, composed of jagged, swirling bacterial masses that twitch erratically as it emits haunting howls in the distance. Another is the Fleetwood, a grotesque amalgam of slime and organic matter, its surface rippling with sickly green hues and covered in writhing tendrils that leave corrosive trails behind. These creatures blend seamlessly into the decaying environment, preying on the weakened and disoriented, turning Level 0’s oppressive emptiness into a creeping nightmare where both the environment and its inhabitants erode sanity and survival alike.