Cepheus Engine Setting Traveller Umbral

Casting Campaign Seeds into the Umbral Stars – Ambassadors and Chaff

Umbral Stars is my original SF RPG setting, where a thousand years from now, humanity has spread across the galaxy at FTL speeds but it still takes a decade to cross it. Set on the other side of the Milky Way in the “observation shadow” of the galactic hub, Earth’s policies still impact the people way out in the Far Fringe, even if Earth has no direct, daily influence on frontier systems.

Logo for the Umbral Stars science fiction RPG setting


Here I’ll discuss ideas for entire RPG campaigns. Each one is a way of looking at Umbral Stars and exploring its ideas.


The PCs are the crew and officers of a Penny Republic “Embassy” ship, which travels from world to world, helping and protecting people. From time to time, they may visit a world that is not a member of the Republic and negotiate the conditions that the world may join.

The Penglaian Republic (usually called the “Penny Republic” in a playful, non-pejorative way) is a group of a hundred star systems that have banded together for mutual aid in a loose confederation of planets. The Republic’s overall philosophy of government is a sort of anarcho-socialist-democratic system which values personal freedom and freedom from discrimination, public services and general welfare, and responsible and humane capitalism, but it’s a system in which joining is entirely voluntary.

The Republic offers bundles of services to its client states, all of which are entirely optional, but there is a minimum bundle that a planet must sign on for to be a member state. Each bundle comes with a price, meaning taxes, and conditions, like guarantees of the rights of the planet’s citizens. If a planet can meet the conditions and pay the taxes, they can purchase services like mutual aid and protection, education, public works, and economic trade.

If you’re thinking “protection racket,” it’s not that. The Republic never threatens the worlds that turn down its membership offer. It just doesn’t protect them from other, real threats or help them lift up their people. Of course, the ambassadors are good people and often help anyway, at least one time, if only to show the world the benefit of membership before they leave.

Embassy Ships are large starships that make circuits of member worlds, collecting taxes, ensuring compliance with Republic laws, defending worlds from pirates and other interstellar banditry, building infrastructure and public works, and setting up interstellar trade and banking. The ships carry sufficient teams of dozens of experts in all kinds of fields, plus a large contingent of soldiers.

PCs run the teams. The problems the PCs run into usually need expertise from more than one team. It’s a bit like Star Trek, but without the Prime Directive, and without the Captain’s overwhelming need to come to the aid of people in need.


The PCs are the owners of a salvage operation that visits planets that are still being terraformed. The giant terraforming machines leave behind all kinds of high-tech gear until the very end, when it is reclaimed. There’s a window where a team can get on-planet and collect a bunch of it. Then they sell it on the open market.

The Terraformers are enormous self-replicating starships that are spreading out among the stars of the galaxy. They pick one planet in a system to terraform, then build up a giant infrastructure all over that solar system to harvest materials, move them to the planet, install them, and convert the planet to a human-habitable condition over a period of a decade or so.

The process creates automated factories, mines, and power plants all over the place. The Terraformers stay in the system until the job is complete, probably building one or two more Terraformers, as well. Then they collect all their machinery and go. The only thing they leave is a single Factory, quietly humming along in a quiet state, waiting to help the planet’s first inhabitants get started.

While the terraforming process is ongoing, there’s a lot of material (colloquially called “chaff”) that can be taken. Of course, the Terraformers have developed anti-piracy drones and other protection, so it’s not entirely foolproof. Teams who collect the chaff call themselves “threshers,” for the obvious reasons: they feel they are separating the unimportant, replaceable bits from the process. After all, if the Terraformers lose a factory or something, they’ll just replace it. Yeah, it takes them a little longer to rebuild and finish the terraforming process, but it’s not like the Galaxy really needs more worlds at this point. Or so the Threshers say.

Lots can go wrong on a Threshing mission. The Terraformers are artificially intelligent and protect themselves. While most of the protocols are known, sometimes you meet one that has new tricks, special defenses, or very aggressive attacks. Sometimes the conditions of the world or solar system are dangerous, with lightning storms, high winds, volcanic eruptions, or other calamities associated with world reconstruction. Sometimes there are other Threshers there and they don’t mind shooting you to guarantee their take. Sometimes there’s a local government waiting for people like you, because they have a vested interest in making sure this particular world finishes at the scheduled time.