Mars City Shadowrun
Here’s where the working-class folk live. The undercity is literally under the upper city, and there are places that don’t even get sunlight. You don’t wanna hang out in those places too long, unless you’re a local or you’re really looking to fight. All sorts of degenerates and wild-eyed ruffians might accost you. Public transit is limited to automated maglev trains. There are road-ramps and elevators to the uppercity from select points as well, but they are monitored by cameras and sensor systems to watch for criminal activity.
The small central part of the undercity was the site of the original colony, back in the early days. Back before the troubles. Whoever it was that decided to build directly on top of it for their shiny new city sure had one hell of a sense of humor. Or maybe just a lack of metahumanity and a short-sighted sense of history. (Hell, it’s probably because it’s cheaper to build on top than to lay down a new highway.) No one really goes down to the core anymore. Or rather, no one ever comes back out to talk about it.
The rest of the undercity is ruled by a variety of street gangs and criminal syndicates ranging from the sadistic to the merely petty. It’s certainly more livable than the core, though, and rent’s a hell of a lot cheaper than in the upper city. The security situation ranges wildly depending on who is in charge of the sector you are in (turf is mostly divided along the lines of the massive struts that were dropped thru the original city to support the upper city). The same goes for services available, employment opportunities, and lifestyles.
The main appeal of the undercity is the low cost, and the low chance of official interference in whatever it is you choose to do. The cops only come down when they’re looking for someone who really pissed off someone in power, but when they do come down, it gets pretty brutal pretty fast, so it’s best to lay low and stay out of it – if that’s an option. Same goes for corp hit squads and runner teams. Nobody really worries to much about collateral damage, so folks have got to look out for themselves.