Welcome to the Firmament
Collectively known as "the Firmament", the setting can be divided into three regions. For a map of the Firmament, click here.
The Foundation is a set of 4 star systems, all of which are located very close to each other. It's also the name of the Firmament's interstellar government. The Foundation systems are the oldest human systems, and were the first to be colonised. Some would call it the capitol of human civilisation and pinnacle of human achievement; others would call it a repressive oligarchy ruled by a hereditary elite. Play here for dystopian fiction lived in a world rife with surveillance, where class is a universal law.
The Incorporated Colonies are made up of 12 systems that stretch out like arms from the Foundation. These are the systems that were settled during the initial boom of interstellar colonisation that came with the invention of the spike drive. When the Tau Ultimatum was broadcast throughout the Firmament, they were brought under the Foundation's wing. However, they still retain a significant degree of autonomy. Less central power and surveillance means it's easier for corporations to do whatever they want. Play here for cyberpunk and corporate intrigue.
The Rim makes up the far reaches of inhabited space: 8 lonely colonies far from "civilised" worlds. As more of the attractive systems were colonised, settlers had to go further and further out to find suitable colonies. They are far enough away from the Foundation that they were able to remain independent, but this independence comes at a cost. The Rim is the poorest and least technologically advanced part of the Firmament. Play here for Firefly-style space western adventures.
About the Setting
Disconnected diaspora. Faster-than-light travel exists, but it can't cross the galaxy in an instant. A voyage between two colonies separated by many parsecs can still take weeks or even months to complete. This means that interstellar travel is still a significant endeavour. Individual systems need to be relatively self-contained and self-sufficient, as interstellar transportation of bulk goods like food or raw materials is not feasible.
No robots. There are advanced autonomous systems, but true general artifical intelligence either doesn't exist or is being kept very quiet. The only robots you'll encounter are operated by a human, or by simple programmed instructions.
No aliens. At least, none you'd care to speak to. Many of the worlds settled by mankind have native biospheres - whether miscible with humanity or not. These might be anything from microbes to ocean life to rich and vibrant flora and fauna. However, no sapient alien life has ever been discovered.
Low-tech science fiction. Most of the Firmament is pretty low tech. Sure, laser guns and force field generators exist - but they're restricted to the rich and powerful, particularly megacorps and the oligarchs of the Foundation. Most spacers are still using guns and armor that would be recognisable in the present day. The gunpowder cartridges might have been replaced by electropneumatic systems, but the design is still the same.