⠀Level 0 is an expansive non-Euclidean space, resembling the back rooms of a commercial building. All rooms in Level 0 share the same superficial features, such as worn mono-yellow wallpaper, old moist carpet, scattered electrical outlets, and inconsistently-placed fluorescent lighting. Aside from these common features, no two rooms within the level are identical in layout.

The fluorescent lighting in Level 0 hums at a constant frequency. This buzzing is notably louder and more obtrusive than ordinary fluorescent lights, and examination of the fixtures to determine the source has proven inconclusive. The most prominent threat in Level 0 is the stark lack of available resources; as the fluid saturating the carpet has been deemed unsafe for human consumption, most are likely to perish before managing to find an exit due to extended dehydration, starvation, and exhaustion.

Linear space in Level 0 is altered drastically; it is possible to walk in a straight line, return to the starting point, and end up in a completely different set of rooms than the ones previously traversed. Due to this phenomenon, and the visual similarity between each room, consistent navigation of Level 0 has proven very difficult. Devices such as GPS locators and compasses fail to function within the level, and radio communications are audibly distorted and often prove unreliable.

Above the ceiling tiles in Level 0 lies a cramped, dark space, roughly one meter in height. The air in this area is stale and thick with dust, making it difficult to breathe, and electrical wires line the ceiling in all directions. Attempting to use this space as a means of navigation is impractical, as the ceiling tiles easily give way under pressure.