Scum are nomadic space gypsies, traveling from station to station in heavily modi ed barges or swarms of smaller space vessels, mostly former colonial ships. The term “scum” has been gleefully appropriated from its original derogatory usage. Despite their reputation as criminals and scam artists, their temporary presence is often tolerated in many habitats for the entertainment they bring in the way of exotic performances and storytelling, both of which offer change and relief from the isolation of remote habitats and clusters. Their thriving black markets are an open secret but shut down only in the most oppressive regimes, as citizens returning with illegal goods must pass their station’s security anyway.

The scum themselves comes from all manner of backgrounds. They are rejects, anarchists, criminals, societal dropouts, wanderers, artists, eccentrics, and more. As a culture, however, they embrace experimentation and an “everything is permissible” attitude. Many are ardent practitioners of extreme transhuman modifications. Long-time scum are sometimes scarcely recognizable as having once been human. Scum economies are transitional rather than new, due to their constant interaction with other habitats, though among long-term residents an underground new economy often flourishes.