The Bore Rats are the Underworld's indigenous workforce — tunnel runners, excavators, salvagers, and guides who operate in the unmapped sections of the tunnel network beneath GLMZ. They are not a gang in the conventional sense. They have no territory to defend because the territory they operate in doesn't officially exist. They are the people who know the deep tunnels, the ones who go below the maintenance corridors, below the utility conduits, into the sections where the geometry stops making sense and the walls are warm.

The Bore Rats originated in the 2160s when the early expansion of the Underworld created a demand for human tunnel workers who could navigate spaces too irregular for automata. The original Bore Rats were construction laborers — hard-rock miners, concrete crews, boring machine operators. When the official expansion projects ended, the workers didn't leave. They stayed underground because the tunnels had become home, and because they had discovered that the deep Underworld contained things worth finding: pre-collapse infrastructure, sealed chambers, salvageable materials, and spaces that the corponations didn't know about and couldn't control. The Bore Rats became the Underworld's native population — the people who live where nobody else will go.

Today the Bore Rats number approximately 400-600 active members spread across the entire GLMZ tunnel network from Green Bay to Chicago. They operate as a loose guild with a reputation-based hierarchy: you earn standing by going deeper, staying longer, and coming back with something useful — or with information about what's down there. The deepest Bore Rats, the ones who work below Level 12, are treated with a respect that borders on reverence by the rest of the guild, partly because of the risks they take and partly because they come back changed in ways nobody discusses directly. They see things in the deep tunnels. They don't talk about what they see. They don't need to. The other Bore Rats can tell by looking at them.