Maintenance shafts are corridors that run beneath or throughout a building or a complex of buildings and are used to maintain critical infrastructure. Fictional maintenance shafts may offer a protected or secret means of travel if there is danger elsewhere (and are not already being used by the danger). These spaces may contain pipes, catwalks, steam vents, and flickering lights. They may connect to maintenance rooms, elevator shafts, and ventilation systems. Maintenance shafts are home to blue collar maintenance workers, people plotting clandestine infiltrations of nearby buildings, and monsters.

Consider what types of maintenance can be performed from this location. Can the power be shut off, servers reset, or hangar bays doors opened? Maintenance tunnels provide worldbuilders designing game-oriented worlds opportunities for players to sneak around the area, but also alter it or complete missions. In narrative worlds, maintenance tunnels may be dangerous areas, but the only way to reach some other location or fix some current pressing issue.

Pipes

Ventilation Systems

Catwalks

Setting an unnerving tone for a maintenance tunnel or broadcasting an ambush ahead? Try a dark corridor.