Inferno Protocol

The maze does not stay still. The corridor you came from won't be the corridor you go back through. Spray the walls. Drop chalk. Leave objects behind. Find old hand-drawn paper maps and figure out which ones are lying. A compass helps, until it doesn't. Remember: Memory is your map. Marks are your guide. The maze keeps changing. Corridors give way to forests, deserts, frozen halls, places that shouldn't be underground.

Others walked here before you. Notes, scratched-out warnings, sketches on the walls, most of it panic, some of it useful. A few point to injectors. A few point to exits. A few point to things you shouldn't go near. Whoever left them isn't around to ask.

People live in here. Not many.

There's a settlement at the center where you can farm, build walls, and craft what you need. Outside it, smaller camps survive in the corridors. Some will talk, some will trade, some won't wait for you to draw first. The rules of the maze cost more than ammo.