Patricians, Equites, and Proles

While each of the home systems have their own local social structures based on thousands of years of history and the unique physiological and psychological trait of the native species, the interstellar mining industry has produced its own system of social organization and hierarchy that is common throughout most colonies, outposts, and mining worlds.


The patricians are the elite of interstellar space. While they make up only a small percentage of the population, they control the vast majority of all wealth and capital. They are almost all descended from early founders of space industry companies from the homeworlds who happened to be in the right place and time to amass huge fortunes that later provided the capital to establish the infrastructure needed to establish mining colonies in other star systems once hyperspace travel became a possibility. By owning the infrastructure that made travel, trade, life, and work outside the home systems possible, these families gained near total control over the entire interstellar economy and in many cases direct owners of all property and facilities in the systems they developed. Since the early days of the establishment of the current interstellar economy, the patricians have become increasingly aristocratic and generally consider themselves completely separate from the rest of the population, being rarely seen in public by the common people.

Nearly all major companies doing business in interstellar space are being privately owned by only one or two patrician companies. It is much more common to give loans to other companies that are short on capital for investements than to purchase shares in the companies of other families. Personally owning their own companies with tens or hundreds of thousands of employees is a great source of pride for patrician patriarchs and matriarchs, and their source of legitimacy as a distinctive elite. The mining, manufacturing, and shipping industries are what made them rich and powerful and what enables the prosperity and comforts enjoyed by the people in the home systems. Getting rich through financial trading is beeing looked down upon and not considered a proper activity for distinguished gentlemen and ladies. Though in practice most of the big conglomerates also include massive banking divisions that produce a significant share of their profits.


The term equites originally refered to people who have invested some of their own money into companies they don’t have full ownership and personal control over. However, it has long since taken on a meaning that refers to all non-patrician people who have sufficient personal funds to engage in any economic activity of their own or own property. This social class consists of small business owners employing tens or hundreds of workers, as well as the vast armies of accountants and analysts handling the day to day transactions and administration of major companies and are considerably better paid than the more menial industrial jobs.

Equites typically make up between a fifth and a quarter of the population on most planets and stations outside the home systems. Equites can rise quite high in society and gain access to the inner management circles of the largest companies, and in some rare cases even mary into patrician families. But they will always be remembered as being from a lower class and can never become true equals of the patricians.


The proles are the working class and make up the vast majority of the population of interstellar space. Most proles work for the same company their entire lives, which is the same company their parents and grandparents worked for. In the early days of the industrial development of the New Frontier, large portions of proles were hired directly from the homeworlds, but this immigration has virtually stopped for almost a century now. Originally, skilled workers from the homeworld were lured with the promise of high wages, but with the high reliance on imports for all but the most basic goods, the cost of living in the colonies and mining worlds is extremely high, and life for most proles ranges from modest prosperity at best to abject poverty. When mining companies ceased operations in the New Frontier, sometimes they would have no further need for the workers or it would be cheaper to higher new staff close to newly opened sites than to provide for the transit of existing employees, and proles would be simply abandoned on exhausted planets to fend for themselves. This practice has led to the creation of numerous small independent mines by unemployed miners who are barely scraping enough ores from the ground to make something of a living.

For Coriolis

Patricians, equites, and proles replace the privileged, stationary, and plebian upbringings of Coriolis and have identical mechanical effects in character creation.

The New Frontier

The New Frontier Survey was one of the largest astrometric survey projects ever undertaken in the history of Known Space and has not been surpassed in the following more than 300 years. A consortium of many of the largest mining companies at the time comissioned the surveying and calculation of hyperspace routs for 16 new sectors, increasing the mapped area of the galaxy by over 5%. Great hopes had been placed on the discovery of significant easy to access resource deposits, and while initial exploration missions to the most promising systems turned out quite promising, the overall commercial success of the project has become widely regarded as somewhat disappointing by the space mining industry.

The initial gold rush for the most valuable mineral deposits lasted barely a century, after which the productivity of newly opened mines only slightly exceeded those being operated much closer to the home systems, barely justifying the additional deep space transportation costs. Since then, the New Frontier has seen a slow but steady decline as, and most mined and refined elements end up in the few major colonies that have been established in the region instead of going to the main markets in the home systems where they sell for significantly higher prices. Some of the New Frontier sectors have already been completely abandoned by the major mining and industrial companies, but those closer to the core sectors of Known Space, which have seen the establishment of several major colonies, are believed to have a sufficiently large and stable population and economy to survive long term as part of the interstellar periphery.

The discovery of a native population on Talassan resulted in the immediate establishment of a 100 lightyear exclusive economic zone around the system according to standing interstellar conventions. After initial contact was established by a delegation of the Galactic Community, there was a strong support among most major local Akiiru governments to put a ban on interstellar companies operating within their space until an international body could be established to make trade deals and grant commercial licenses and exploitation rights on behalf of the whole planet. Since then the Akiiru have been extremely cautious, greatly limiting trade with other worlds to prevent the local Talassanian economy from falling under the control of foreign powers. The integration of Talassan into the interstellar economy has been very slow, and while the planet’s Akiiru population vastly outnumbers that of all the colonies in the New Frontier combined, its significance as a market for foreign companies still lags well behind several of the colony worlds.

In addition to the 3 billion Akiiru on Talassan, there are about 200 million colonists and mining employees living in the New Frontier. This number is assumed to remain relativly stable over the next 100 years, but likely to see continued migration from the failing mining worlds to the larger colonies with fully developed local economies. Many of the major mining fleets getting relocated to other regions of Known Space is having a huge impact on the numerous trade companies that largely relied on the miners as customers for consumer goods. With this market continuing to fall away, competition between them has become increasingly fierce, frequently involving bribery, dealings with pirates, sabotage, and even assassination. The recent establishment of an Akiiru colony on Palan, close to several other planets with considerable populations, has rekindled some hopes of Talassan opening up as a major available market, but competition among the struggling merchant houses is expected to become quite explosive and could potentially risk the Akiiru closing off their internal economy completely.

While Known Space is a much larger region of the galaxy and home to the homeworlds of the various species that each have populations in the bilions, I think that the New Frontier is probably going to remain the entirety of the Iridium Moons setting. The cultures of the home systems and the interactions of the main interstellar powers don’t really interest me and I like the idea of the small worlds of the New Frontier being basically forgotten by the rest of the galaxy, left to the patricians of the big mining and trade companies to treat as their private fiefdoms.

Major Peoples of Known Space

At this stage of the development, the humanoid species that inhabit the Iridium Moons setting are still not completely locked in and I am still occasionally making some changes to the full lineup. But that has been limited to the smaller players on the interstellar stage, and the main species that make up the core of big influential power groups and the majority of the populations on most planets have been very well set for many months now. The peoples covered in this post will almost certainly remain largely as they are now in the final version of the setting, and by having these five introduced for now there should be enough established context to let me meaningfully write about all kinds of other aspects of the setting I already have to share.

While the theory and technological requirements behind the construction of hyperspace drives is comparatively straightforward and has been developed many times independently, the science of being able to actually navigate a ship moving through hyperspace is widely considered to be the greatest challenge is physics and known to have been discovered only twice in the history of the galaxy. Even on planets that had developed spaceflight several thousands of years earlier, the ability to travel to other star systems only became available to their people once they had been visited by ships from other worlds that shared the secrets of hyperspace navigation with them. In the centuries since the Damalin discovered hyperspace travel, the homeworlds of some two dozen advanced civilizations have been connected to the hyperspace route network established by them. About half of which have since then developed interstellar industries and established outposts and colonies in other systems and are regularly encountered in spaceports across Known Space. Of these peoples, five make up a significant majority of travelers, workers, and settlers outside of the home systems and control most of the interstellar mining industry and starship manufacturing.


Of all the peoples working and living in interstellar space, the Enkai are the most numerous. They were one of the first civilizations discovered by the Damalin after their rediscovery of hyperspace travel and since then have established dozens of colonies, many of which have by now grown to populations in the tens of millions.

Enkai are of medium stature compared to other peoples and typically stand out even from a distance by their striking orange-red skin. Their homeworld is dominated by a comparatively drier climate than the planets on which most other species evolved, and while they are most comfortable in moderately warm savanna environments, this makes them one of the most tolerant peoples for the harsh desert environments that are most common on planets with breathable air. While Enkai are somewhat of a rare sight in colonies with wet and humid climates, this environmental adaptation has made them become the most widely spread out and numerous people of interstellar space.

Even compared to the other civilizations of Known Space, the Enkai culture is highly fragmented and the large population of their homeworld divided into over a hundred fully sovereign nations and no single representative organization in interstellar affairs. While now relatively rare, minor wars on the Enkai homeworld still happen every other decade, typically unnoticed by the rest of the galaxy. Enkai living in interstellar space typically identify strongly with their own home planet but generally lack much of a shared identity as a species as is common with most of the other peoples. In complex conflicts, the species of other groups generally have no meaningful impact on which sides they pick.


Unlike most of the species of Known Space, the Damalin already traveled between the stars over 2000 years ago. Their homeworld used to be a minor client state of a vastly larger interstellar civilization, on which their ancient spacefarers relied entirely for ships and navigational charts. When this older civilization fractured and showed signs of collapse, the Damalin homeworld was one of the first that became separated from the hyperspace route network and without regularly updated navigational data, their few hyperspace jump capable ships became stranded in the system. It took many centuries for the Damalin to economically recover from the loss of interstellar trade and over a thousand years before they managed to independently develop the technologies to create new hyperspace chart. By that time the nearby colony worlds that the Damalin used to have direct contact with had long been abandoned and they have never been able to discover what eventually happened to the older civilization. The Damalin system for creating navigational charts and hyperspace routes became the basis for the entire currently existing network of routes that make up Known Space.

The Damalin are an amphibious species of slender humanoids who tend to be on the taller side for the peoples of Known Space but rarely grow over 2 meters tall. They can breath both air and water indefinitely but quickly develop skin irritation when out of water for more than a day or two. Long showers will do in an emergency, but all Damalin ships and homes have often several bathtubs used for naps when larger fully submerged areas are not possible. Even though they are not a particularly numerous people, Damalin have been establishing colonies in other systems for such a long time that they are common sights nearly everywhere in space, and Damalin patricians own many of the oldest and largest interstellar companies.


The Netik civilization is incredibly old, being believed to first developed agriculture and build the first cities on their homeworld nearly 60,000 years ago. However, the Netik who today inhabit the worlds of Known Space are all descendants of ancient colony worlds established long ago in the age of the previous interstellar civilization that first brought hyperspace travel to the Damalin as well. When the ancient civilization collapsed, the Netik had already spread across many worlds, which eventually became separated from the hyperspace route network and remained isolated for well over a thousand years. When the Damalin rediscovered interstellar space travel, nearby Netik colonies were the first planets they visited in their explorations. Many of which had gone extinct over the centuries, but a number of them that had been established on planets with particularly favorable environments had grown to populations in the hundreds of millions in the meantime. Once they regained the ability to travel between the stars, these Netik colonies quickly began looking for other surviving colonies, but even in nearly 500 years of searching, they have never been able to rediscover their original homeworld. As a people without a homeworld, the Netik are far less numerous than any other. But with the populations of the other peoples living almost entirely on their respective homeworlds, the Netik are actually make up a large fraction of the population of interstellar space, being nearly as common as Enkai and Damalin.

Even though the physical appearance of Netik is regarded as highly alien to most other peoples of Known Space, they actually have a well deserved reputation of being very easy to get along and having a highly developed ability to judge emotions and finding the right way to talk with people that they react well to. Netik companies are heavily involved in the space mining industry and the construction of the largest superfreighters used for ore hauling.


The Chosa are tall humanoids with tough green-gray hides and sharp teeth that give them a reptilian appearance, but otherwise very similar to Enkai in their overall body structure and stature. They are among the physically strongest of the species traveling interstellar space and fight fiercely and with little hesitation. Prejudices are widely spread among the other species of Chosa being violent brutes, but their homeworld actually ranks among the most technologically advanced planets in Known Space. Their ships tends towards blocky and practical designs typically regarded as looking blunt with little thought for decorations, but compare well in their capabilities to all but the most sophisticated Damalin and Netik ships.

Chosa encountered in space are often mercenaries, an occupation that their physical toughness and familiarity with advanced space technologies makes them well suited for. Chosa culture as a whole is not overly militaristic though, and their prominent presence in the mercenary business comes more from them being very well suited for the demands of that line of work. There are typically not a lot of opportunities for Chosa engineers or pilots outside of Chosa systems, but they are on average not far behind in their skills than the Damalin, Netik, and Enkai who dominate the profession.


The Tubaki are one of several peoples whose presence in space is greatly dependent on technologies and infrastructures of other species. There is only a small number of Tubaki shipyards and most of them are primarily specialized on converting old purchased ships from other manufacturers to provide greater comfort to Tubaki crews. Those shipyards that do build their own ships still rely on imported hyperspace drives and gravity generators from other more established companies. Despite Tubaki worlds being generally seen as more low tech planets, Tubaki have been traveling through space for centuries and founded several dozen of colonies in other sectors. Even though most of them are of no interest or relevance for major interstellar companies.

Tubaki are humanoids quite similar in size and proportions to Enkai, which is generally attributed to the very similar gravity and climatic conditions on the Tubaki and Enkai homeworlds producing a similar optimal body shape for upright walking humanoids. On average, Tubaki tend to be slightly taller and more muscular, but mostly stand apart due to their sand to brown colored fur and thick manes. Tubaki found outside their own system are usually employed as manual labor, primarily in mining and agriculture and also various low-level mechanic jobs. Tubaki colonies are usually too small to have advanced engineering and science schools and those individuals with advanced degrees typically find their calling in contributing to the development of their planets rather than seeking their luck among the stars.

Some things I figured out about running Space Opera campaigns

One thing I discovered since I started working on the idea of creating a Star Wars inspired campaign in an original setting is that Scoundrels with a Spaceship has actually become a genre in itself. Traveller, Stars Without Number, Scum and Villainy, Coriolis, and  Rogue Trader are all RPGs based on that idea, and it has of course always been one of the three campaign styles for half a dozen Star Wars games. Firefly is widely considered a prime example of the genre outside of RPGs, as is Cowboy Bebop, and you can count TheExpanse as well. I think in RPGs, the Space Scoundrel might very well be the second most common archetype for PCs, after the heroic fantasy adventurer.

And it makes sense. It’s a great concept for player characters in a space setting. Characters who are their own boss, who don’t have to take orders from anyone, are not expected to risk or sacrifice themselves for others, are permitted to solve problems by shooting but also to do business with awful people, and who can go wherever they please in their own fast ship. It’s as much freedom as players can have in a game. Which is great.

But being expected to be largely self-interested is also a problem. The players are free to do anything they want, but the archetype also tells them to always ask “What’s in it for me?”

It’s a fun scene when selfish Han Solo decides he’s had enough with all this nonsense and is just going to sit the rest of it out and wait for Obi-Wan so they can leave, and Luke has to really put all the work to get him to help save Princess Leia. But it’s fun about once. And only because we can watch it unfold without having to do the work. In the end, Luke only gets him to cooperate and have more adventure by promising him that there will be a huge reward. And once he gets his cart load of money, he’s immediately annoncing that he’s done and is out of whatever else Luke and Leia are uo to next. As GM or a player, you really don’t want to have to go through this whole song and dance with other players who think it’s spot on for their characters every two weeks. This stuff is getting really tired after 2 minutes.

As I have come to see it, having adventures that have the events of the campaign largely scripted out pretty much defeats the purpose of RPGs. Nobody gets into RPGs for the first time because other players tell about cool stories they are getting told. It’s all about the promise to be able to create stories and play characters who can go everywhere and do anything they want, and the GM can immediately describe how the world and other characters in it respond to that. What’s the point of customizing your character’s abilities and doing all the dice rolling when the overall sequence of events and ultimate outcome are already determined?

But how do you have grand adventures full of excitement and thrilling danger when the default assumption for the PCs is that they are only looking out for themselves and have no desire for justice? As cool as the concept of the space scoundrel is for characters, it’s not actually a greating starting position for grand adventures. This has been on my mind for quite a while, but thinking about it more deeply over the last few weeks has led me to a couple of conclusions on what might be done to mitigate these issues.

The campaign needs a clear premise: When you want to run or play a campaign about a bunch of space truckers, you probably don’t want to actually do a campaign about space trucking. Some people might actually looking for that, but generally when you get into this type of games, it’s the promise of action packed adventures that draws everyone in. It’s the times when the space truckers get interupted in their space trucking when all the cool and exciting stuff happens. Flying around in your ship and being free to take on any job you want sounds very interesting, but I think you need to be more specific and narrow down more clearly on what will actually happen in this campaign. It can be the GM who creates a more specific outline, or the players who decide on a specific theme they want their adventures to revolve around.

The characters and activities should match the premise of the campaign: This sounds super obvious when you phrase it like this, but it really isn’t. When the premise of the campaign is space truckers and the players make characters to be good at space trucking, but the adventures turn out to be primarily exploring an alien jungle planet, or fighting off an alien invasion, there will be a misalignment of expectations. Instead, the premise of the campaign should have been about space truckers who find themselves on a  alien jungle planet which they are going to explore. The characters the players make may be almost identical, but it will likely make a real difference in how the players will go around looking for adventure. Instead of looking for ways to get their ship back into space and deliver their cargo, they’ll be more likely to embrace diving into the jungles and their mysteries.

To get players to be proactive, they need to be invested in the world: If the primary motivation for players and characters is to get rich by cashing in job payments, or to pay off angry dangerous people who are after them, then there is little to motivate them to go towards the danger. Which is where all the really cool and fun stuff is going to happen. To get players to not just grab their money and leave as soon as possible after dealing with the issue of the current adventure, they need to care about what’s going to happen to NPCs, groups, and places that are still being in danger. To protect themselves is typically very easy for PCs, especially when they have a space ship. Just leave. But when the players also care about the fate of people who can’t just leave, they have a reason to stay and continue confronting the threat. Early adventures in a new campaign should attempt to get the players invested in the conflicts of the setting.

Don’t start the campaign with nobodies who have no connections: For some reason, the generally assumed common start for characters in a new campaign is that they are completely new nobodies who have not done anything significant yet, since they start out with the minimal character stats and have no experience points. They also have no connections to anyone, since the players have not yet meet any other characters in the game world. This works well enough in an oldschool dungeon crawling campaign where every aspiring adventurer from the street can just stroll over to one of the old ruins at the edge of town and start scavenging for ancient treasures while fighting off roaming monsters. But this really provides nothing useful for campaigns with a more narrative focus and when there is no destiny for the characters waiting to be fulfilled. Instead of waiting for the players to find some justification for their roaming, self-interested characters to get themselves involved in other people’s business, have the players make characters who are already involved. Han Solo was already an established smuggler with considerable reputation, who had dangerous people coming for his head when the story starts. Even Luke is not a nobody who randomly decides to rescue a leader of the Rebellion he know to be in trouble. Before he goes to try saving her, he learns that Obi-Wan is an old pal of his father and has his home and family destroyed by the Empire’s terror. When the adventure actually starts, he is already very involved.

Money is still really attractive: In many fantasy games, all the beat equipment is magical and can generally not be bought with money. And all the best weapon and armor that money can buy can typically be afforded after the first adventure. From that point on, promising the players that they will be paid great rewards generally does very little to make them any more motivated to do something than they already are. They probably would do it anyway even if there was no reward. But that’s typically not at all the case in Space Opera. Really heavy power armor or big ass guns might be very rare and highly restricted, but there’s probably still thousands of them that have been produced in a giant factory, rather than being the unique life’s work of some wizard. And when it comes to spaceship upgrades, there is pretty much no limit. There is always going to be more better and cooler stuff to buy and the players will never sit on money for which they can’t find a good way to spend it.

The Three Fantasies and the Great Filter

My own approach to Space Opera is that it’s a genre that is really mostly fantasy set in space and rarely has anything more to do with science except using real physics terms that the writers don’t seem to actually understand. Scientific realism is just not something that is ever a concern in Space Opera. Though that being said, I fancy myself as understanding quite a bit about physics and astronomy, as well as having a basic grasp of demographics and economy. And while I generally try to not be bothered by it, I do regularly notice when writers have characters say things that clearly make no sense. And it always hurts a bit.

Even when we consider Space Opera to be just fantasy, and that in fantasy you can just make up whatever rules of nature and the supernatural that you want, I still have the expectation that those altered rules are being followed through. There is nothing wrong with making up any new rules for a world you can imagine, but all the things that you did not explicity alter should still continue as they do in reality. It’s a fantasy not adhering to its own rules that bothers me in poorly written space adventures, not that the rules are breaking real physics.

The Three Fantasies

When I notice things in Space Operas that break the established rules of the setting, I often get thinking about how these things could be fixed without having to significantly alter what happens in the story or completely throw out the conventions of the genre. And I’ve come to regard some of these fixes as being actually really interesting things to explore and having great potential to give a new setting a unique style and personality. A short list of items that I had noted down over several years is what ultimately made me decide to start creating Iridium Moons. But even with all these elements that could still be fun if they followed the actual rules of reality, there were still three things left where I feel made up fantasy rules are necessary to evoke the overall style of Space Opera that deeply speaks to me.

  • Hyperspace: Objects and signals traveling through space faster than light is simply not possible. It doesn’t actually have anything to do with light specifically but is the speed of causality. It’s not even that we have not found anything faster than light, but when you look into the physics of it, the very concept of anything faster makes no sense. The limit also plays all kinds of crucial funademental roles in the way sub-atomic particles interact with each other. If you mess with the speed of light, you annihilate all of physics. Hyperspace is the quick and dirty solution to this problem. Assume ships can travel through another dimension where the laws of physics are different (in a way never explained) and all of physics as we know it remains untouched.
  • Artificial Gravity: Unlike faster than light travel, this one isn’t even necessary. When you film actors on a spaceship, having things fall to the ground and stay there is just very convenient and cost saving, but any other medium has no such constraints. And there’s actually physically very simple ways to simulate gravity through constant thrust or rotation. But this has significant consequences for ship design, and my overall stylistic vision for Iridium Moon just really meshes well with early 20th century cruisers in space. Artificial gravity is not neccessary to make the setting work, but I feel not having it would be too much of an aesthetic departure from the works whose style I am trying to evoke. How does it work? I have no idea. There’s no explanation for it. It just does.
  • Human-like Species: I recently noticed that I’m not actually very interested in magic in fantasy, and similarly I don’t particularly care about the alieness of alien species. While there are strong evolutionary reasons why things like bones, teeth, and eyes would probably be very common and similar among complex animal-like organisms evolved on any planet, such people being bipedal, upright walking, similar in size to humans, and with vertebrate-like faces would be extremely unlikely. And that’s not even talking about the kinds of buildings and tools they would produce. While speculation in this field can be hugely fascinating and really fun,  it’s not something I am interested in getting into for Iridium Moons. And as I said in regards to artificial gravity, I feel aliens that are really just a different skin over a human skeleton are part of the oldschool Spacd Opera aesthetic.

The Great Filter

One of the big questions that lots of space nerds and sci-fi fans often get really deeply into is that with billions of stars and perhaps trillions of planets in just our galaxies that formed from the same materials and through the same processes as the Sun and the Earth, why aren’t there hundreds of alien species that have already developed the technology to talk to or visit us? It seems the universe is capable of producing countless highly intelligent and technologically capable species, and we humans made so many advances in just 10,000 years. Then how come our galaxy isn’t swarming with alien civilizations that are millions of years ahead of us?

There must be something that greatly inhibits either the evolution of highly intelligent species, or the development of interstellar travel. This idea is the Great Filter.

I personally think the Great Filter is something really mundane with nothing mysterious about it. It’s simply that faster than light travel or communication is actually impossible, and that species that have the technology to send out thousands of robots on journeys that will take many centuries to explore planets around other stars consider this a waste of time and resources. And then there’s also to consider that they would have to arrive at Earth at a moment where we had been capable to notice a small metal object in space, which in the lifetime of this planet happened just an instant ago. While I believe that the size of the galaxy makes it innevitable that there are perhaps dozens of other species similar to us, the same size is also why I believe it’s extremely unlikely that any two will ever meet.

But Iridium Moons is Space Opera, and so this doesn’t really have to concern us. However, like most Space Operas, the species of this galaxy all have pretty similar technologies, which in most cases isn’t even meaningfully more advanced than the things we already have today. If these species all evolved independently from each other over hundreds of millions of years, how come none of them is millions of years ahead technologically from the others? How have they not already explored the entire galaxy and still only have knowledge of the few hundred systems that make up known space? If this setting wants to make sense under its own rules, there must be something that has kept this from happening. Another Great Filter.

To make a group of scoundrels with their own small ship that can travel between star systems plausible, hyperspacd drive technology can’t be overly complicated and has to be reasonably affordable. Which means that it’s something that technologocally advanced societies should be able to figure out by themselves. So this doesn’t work as the bottleneck. But I created a system for making hyperspace jumps inspired by Stars Without Number, which requires ships to make relatively short jumps from star to star instead of being able to make longer journeys on a single leg. But instead of using limited fuel tanks (which other Space Opera RPGs don’t have), I came up with a limit on navigation. Traveling through hyperspace is fairly simple technologically, but coming out in a spot from which you can reach a planet with sublight engines within a lifetime is extremely difficult. It requires extremely precise knowledge of the starting location and position of the destination star, and the gravitional effects of any massive objects in proximity to the path. Which requires huge amounts of work with extremely expensive equipment. (And is why players can always only fly to the small number of stars that are marked on the map they are given.)

This is what I picked as the great filter for Iridium Moons. This technology to create hyperspace charts is a gigantic achievement that has been accomplished within known space only once. And also only a thousand years ago. Once one species had the technology to actually make use of hyperspace to reach other stars, they made contact with other species and shared the secret behind it with them. Regardless of how old their civilizations were and what technological level they had reached, they only could start exploring outside their star systems and have contact with other species once they were visited by people who already had the technology.

That technology as a whole is still pretty 21st century, even though some planets would probably already in the year 100,000 of their worlds, is still not being explained by this. But I feel like having all the species of known space having gained access to interatellar travel within only the last couple of centuries makes everything a lot more plausible than trying to imagine a glactic civilization that is many thousands of years old.