Though a myriad of planets and civilisations make up the Galactic Cooperation, some that have been in the Cooperation for some time - or are particularly influential - are of note, listed here. Characters do not have to be from a listed planet here - far from it - but these worlds are presented as a springboard for backstory, factions, and plot.
However, note that since The Incident, it is no longer possible to leave the Keter Borderlands and return to the Core Worlds. Characters from all over the Cooperation are now stuck in the Keter Borderlands, bringing their home-worlds' attitudes and opinions with them.