Back when Space Opera X was Ad Astra m20, I came up with a relatively long list of races. The truth is, however, that I haven't used a number of them at all and I doubt that I would other than as off-hand references or occasional plot devices. Let me briefly revisit that list. First, let's start of with the various cultures of Earth-descent humans.
Keep in mind that by "Earth Descent" I really mean American with some Northern European. These were the only Earth-Descent humans who went in to space and formed the vast numbers of Earth Descent humanity in Known Space.
Earth Humans
Bernese - The most protagonist of my peoples; although I see the Bernese Monarchy as kind of like Britain in the 1700s. The real protagonists are therefore the colonists of the various groups in my sector who are (although they don't know it yet) on the verge of breaking with the Monarchy and declaring independence.
Revanchist Republicans - Although there are a number of other races that make up the Republic besides earth-descent humans, the largest plurality is a kind of much less masculine, more Beta subset of Earth humans who developed in a different area to the Bernese and for whatever reason became more like Democrats than like Men. For a number of reasons (mostly self-loathing), they are more likely to have admixed with xenohumans, so some odd physical traits are not uncommon among them. They do tend to be darker than the Bernese too.
Cilindareates - The Cilindareates are like the space Spartans and space Vikings; tall and Nordic, with a great deal of contempt for most other societies in space; although the reality is that they are bleeding people on the fringe worlds where travel and exposure is more common; too many go "abroad" to serve as mercenaries or for other reasons and find that life outside has more opportunity and possibility than within Cilindarete space. This is especially true for lower classes like the Perioeci and the helots, but it's true for full Cilindareates too.
Janissaries - The Janissaries are a bit mysterious, although genetically they cluster close to the Cilindareates, it's not sure exactly how they formed and diverged from them. They also have a strong warrior culture, although they also have a more individualistic and freedom-centered culture when not actively at war. Their "warrior culture" is more a pride in being prepared to defend themselves very effectively at need and constant readiness. Because of their history as slave-warriors under the latest days of the Marian Empire, some say that they are paranoid at being enslaved again. For whatever reason, their warrior capability is as famous as the Cilindareates, but because they aren't expansionary, or raiders, or otherwise bad neighbors, they tend to be seen more positively. They are also tall and Nordic-like, but are much more likely to have darker hair, and strange silver or gold-chrome colored eyes.
Dhangetese - As opposed to the Dhangetan aliens themselves; Dhangetese humans are the mixed race—but mostly Earth descended—peoples who live in polities that aren't actually ruled by a human ethnic group exactly. They are especially common in Dhangetan space, and by far the majority of those you'll find are from Dhangetan worlds, but there are some other worlds who have essentially the same kind of people, who came up with a blended (yet mostly) Earth-like genetic structure, with some xenohuman admixture. The tend to have darker skin, of various shades of brown, with brown hair and often light blue, green or hazel eyes. They also tend to have "European" facial structure. You ever heard of the Heck Horse? It was an attempt to breed modern horses together to come up with a phenotype breed that resembles the extinct tarpan. It's not a tarpan, its genetics are thoroughly modern. But by breeding various primitive horses together, it looks like what we think a tarpan would have looked like. There's been a similar effort with the Heck cattle, who are supposed to resembled the extinct aurochs. The Dhangetese aren't the result of any breeding project, but imagine that if they were, and the phenotype goal was the extinct Mesolithic Western Hunter Gatherer population of ancient Western Europe—that's kind of what the Dhangetese would look like. (Without all of the hand-wringing scientists who try to suggest that WHGs were "black" which is fundamentally so unlikely that it shouldn't ever have been mentioned. Especially if by "black" they mean "African-like.")
Xenohumans
The most important xenohuman races are
- Seraeans—pale whitish-gray skinned, white or silver eyes, and white or gray (or occasionally black) hair who hail from the Seraean Empire.
- Idacharians—an obsidian-black skinned race of xenohumans that are usually associated as a client or ally of the Seraeans, but who have their own culture and homeworlds. Their hair is also jet black, and their eyes are often strikingly bright; gold, purple, silver, or blue.
- Altairans—blue-skinned (of various hues) with hair that ranges from black, white, gray and various shades of blue, with blue or gray eyes. These are the first xenohumans encountered by expanding Earth-descent humans in the distant past, and there is a long history of the two of them being together during the Old Kingdoms of Marian Empire—although curiously, there's fairly little intermixing between them. Some small amount of Altairan DNA is found in the Dhangetese, but less than you'd think.
- Jaffans—extremely pale-skinned and dark brown eyed people with strangely brightly hued natural hair colors, like bright pink, blue, green, red or orange, etc. They make up a significant plurality in the Republic, and many have intermarried with the Revanchists of Earth-descent, making the immediate identification of one without a genetic scanner sometimes difficult.
- Psarians—with red skin that varies from a dark wine or brick color to bright "candy-apple", with black hair or various shades of red (usually darker than the skin) the Psarians also hail from within Republic space and are usually associated with the Revanchists. However, more of them have fled as refugees and refuse to get on board with the ideology of the Revanchists, so they are found in greater numbers as minorities in places that will take them, like Dhangetan space. In addition to their striking skin color, they tend to have irises that range from bright, fiery yellow to orange and even red.
- Others—I've mentioned a few others, like Ubrai, the green-skinned humans who can do some limited photosynthesis when hungry, to the Carinans who are adapted to heavy-G worlds, but realistically anything beyond what's listed above should be rarely appearing and there's no need to catalog them.
Aliens
No space opera is complete without some alien species, but I'm actually less interested in them than many might think. I like the stories of people and most of the aliens that I am willing to entertain are people-like to a greater degree than many non-space opera science fictions, where exploring the biology and psychology of aliens is a kind of esoteric bad habit that many of the authors have.
- Dhangetans—a kind of heavy-G alien that hasn't lived on heavy-G worlds for many, many generations, and have become weird, flabby, spiny, spindly-limbed mob bosses who breed by budding. Although physically they're nothing like them, in a political/social context, they're not unlike the Hutts in Star Wars.
- Cepheids—think Reptile from Mortal Kombat X. Often associated with the Monarchy as a client or allied race.
- Cetians—think anthropomorphic viper-fish. Also, mostly associated with the Monarchy, but more independent, and more likely to be found in any political arrangement on worlds that have large oceans in particular.
- Death Sages—these space undead were once xenohumans, but now that none of them live in the normal sense, they are possibly more alien than many honest-to-goodness aliens. Most of them are cybernetically modified, and are sometimes also called cyberliches.
- Grays—also sometimes called Reticulans or Zeta Reticulans aren't really a known race, or rather—everyone knows that they used to be around building things that still linger on many worlds as ruins, terraforming much of the worlds that are habitable today, and allegedly stocking them with primitive humans who developed into the various stocks of xenohumans millennia later. Few people think that they're still around; most believe them to be long extinct.
- Kusans—the half-sized "space rats" or "cockroach people" are underfoot across many worlds, especially more lawless ones like the many Dhangetan worlds. Covered in stiff fur, and having four spider-like eyes and mandibles, they are more inhuman than most, and are often seen as little more than pests.
- Skiffers—a humanoid alien with dermal scutes on their backs, and spine-like "hair" on their faces, they can sometimes be seen as "space orcs"; savage and not really quite smart enough to amount to anything much on their own, so they are enforcers and brutes for the Dhangetans.
- Reavers—humanoid aliens covered in short fur, with mane-like stiff hair and sharp teeth, the Reavers are in most cases, infamous as roaming pirates, and have a poor reputation among most humans and non-humans alike—although some individuals live in some of the frontier worlds apart from their more piratical Reaver Main area.
- Apes—gors, chimps and orangs are actually descended from Earth apes: gorillas, chimpanzees and orangutans specifically. Genetically modified many, many generations ago to be more humanoid and intelligent, they are rare, but still live in some places in the Rubicon Sector as individuals or even as communities.
- Hulks—various notably large and strong aliens from heavy-G worlds. Includes Arcturans, Tearaxians, and Oerks. I don't really have much use for them except when I want to throw around the idea of someone being especially strong and scary looking.
