At the heart of the Solarian Conflict setting is Earth and its interstellar neighborhood, consisting of a section of space about fifteen parsecs (45 light years) in diameter. While numerous aliens are native to this sector of space, humanity is the dominant power despite having only become a space-faring people a few decades ago.
To understand why, you must understand how humans came to be in space. Thirty-six years ago, the Durog invaded Earth. Remarkably, humanity fought them off. This feat was possible only because more than half a century earlier humans first became aware of aliens and gained access to highly advanced technology. The governments of that era, faced with the undeniable truth that they were not alone in the universe, created the Singular Earth Alliance (S.E.A.) and charged it with the charter it holds to still: protect humanity at all costs. Operating with unquestioned authority and little oversight, S.E.A. enjoyed near-limitless resources which allowed it to prepare for the worst, so that when the Durog invaded, they were met by advanced technology and a military ready and able to defend humanity. The Durog Invasion then gave humans further access to advanced technology. Every slain Durog stormtrooper, and every captured ship, opened new opportunities to human scientists.
But recall, space is massive, and there is far more unknown than known. Beyond local space literally anything might wait. Things like Mechiinmal and Meks. Mek technology is far more advanced than humans. It takes a typical human ship 150 days to fly from Earth to Guhlopius, a mek vessels can do that in minutes. And Meks are not the most advanced race, they just happen to be ahead of humanity. For all that Meks can do there are many things even more terrifying.
Living in Solarian Conflict
Life is an odd blend of the familiar and unfamiliar.
Earth is changed. Most of it did not survive the Durog Invasion, and not a single government from before still holds power. To avoid the irradiated Radlands, people have clustered into massive cities, and are packed far more tightly than even the most densely populated cities of the prior era. Yet other things march on unchanged. Greedy people, and corporations, still strive to gain an advantage over their fellow human. Money continues to be the root of many of societies ills. Good people still do good things, and bad people still do bad things. Technology too is an unusual intermingling of old and new. Gasoline-powered cars are equipped with engines fully capable of flying through the megacities of the present. Computers are ubiquitous, but networks are scarce. The Internet is gone, while private intranets abound. People still die from diseases, but age-extending treatments allow those with money to live a near-limitless life span.
Off planet, in space, the situation is different. No central government patrols the great expanses between stars, and piracy is a constant threat. On starmaps, humanity controls eight sectors of space, but the term 'controls' can be applied only loosely. Communications travel slower than starships, which means anyone that gets into trouble out in space is almost certainly forced to deal with it on their own. This applies equally for distant colonies that come under attack or freighters traveling between planets. The isolation creates an atmosphere something like the Wild West. Piracy, smuggling, and outright war are common.
And waiting just beyond all of this: the Durog. The ever-present nightmare. Literally, the stories that every race tells when they wish to scare their children. The Durog appeared in this area of space only recently, but they have been seen before, and always in their wake destruction. No one knows their purpose. Could it be as simple as nihilism? Earth's defeat of the Durog was unheard of. Unthinkable even. This fact, as much as any technology S.E.A. commands, puts humanity at the forefront of the arms race. Every other race asks the question, "If humans could turn back the Durog, what hope do we have against them?"
Sothis Station & the Keppler Route
Mek. Hort. Reascopris. Sauran. Durog. These are but a few of the countless races that live outside local space. They traverse this corner of the galaxy regularly, however, entering and exiting along the Keppler Route, a busy intergalactic highway. Imagine a path chartered through the stars, and traversed by tradesmen, bounty hunters, raiders, explorers, and more. Anything could enter our space through the Keppler Route, and recognizing this as a serious threat, S.E.A. built Sothis Station. A massive space station about three parsecs from Earth, Sothis lies on the Keppler Route, and has become a regular stop for those aliens traveling the route. In addition to giving S.E.A. access to their comings and goings, it also provides humanity a regular source for new technology.
The importance of Sothis Station to the interstellar neighborhood has become immense. All the major species maintain diplomatic cores on Sothis, including the torm, and for the first time ever torm and tayvaak sit at the same table and discuss peace. As the only neutral facility in the region, and a stopping point for Keppler Route traders, Sothis has become a massive and thriving mercantile hub. Sothis also operates as a central collection point and source facility to a network of interplanetary 'mail carriers' that travel from system to system collecting and depositing mail. Finally Sothis is connected to Earth via a pair of jump gates - the only gates in the region - which allow traffic between the two locales to occur in moments, rather than years.
Second only to Sothis, is Earth. Home of humanity and S.E.A., Earth is where everyone wants to get. Of course, it rarely lives up to the dream. Even in the massive megacity of Olympus, life is difficult. Outside of Olympus, and a handful of other 'clean' zones, the radioactive Radlands are inhospitable and deadly. Nevertheless, it is on Earth that the neighborhoods power brokers reside. While S.E.A. hordes its technology, massive interplanetary corporations are more than willing to sell tech to the highest bidder. Whether it is Val Core Robotics exporting robots modeled after captured Meks, Rupert Tomilson Systems selling its guns to the highest bidder, or or any of dozens of other corporations, these organizations wield massive influence on Earth and abroad. Corporate offices have been established on as inhospitable locations as the torm homeworld Braktug. And lest you think torm would not suffer the cravenness of human corporations remember a truism of space: the credit is king.
In addition to humans, there are three other major powers in the neighborhood, the Glopians, Tayvaak, and Torm.
Peaceful and friendly, Glopians live on Vlaapus, but they control four sectors of space. They establish control not through force of arms, but through negotiation and mutual consent. Glopians are the closest thing the area has to a truly altruistic species. That is not to say they are universally good-natured. Individually, they are as apt to be cruel and nasty as are humans, but collectively they tend towards kindness and generosity.
The Tayvaak and Torm present a stark contrast to the Glopians. Two distinct races, their societal commonalities outnumber their differences. Both races achieved space travel about 600 years ago. Both races are imperialistic. Both races have a strong military culture. Both races are quick to anger and slow to forgive. With their homeworlds a mere 1.6 light years apart, Torm and Tayvaak have been bitter enemies for all of the 600 years they have known of each other. A key difference between the species is how they respond to others. Tayvaak rule is a soft yoke, and after a planet has submitted the Tayvaak leave the planet to govern itself. Contrarily Torm control is harsh and bitter. When they conquer they displace any local government and replace it with their own.
Glopians and Tayvaak came to the aid of Earth during the Durog Invasion. The Torm did not. For this reason, S.E.A., and most humans, have a dim opinion of Torm.
Every species has differing levels of technology. There are many planets, moons and other celestial bodies in the area with races that have not yet achieved space travel. The major races all share some commonalities among them however.
Every major race has access to faster than light (FTL) travel. Exactly how much faster ships can travel varies by species. A typical human ship requires nearly five months to traverse a parsec, a typical Mek vessel needs only five hours for the same journey while a Torm cruiser might take more than a year to traverse that distance. This is just the commercially available technology. Every species military has more advanced technology. S.E.A., for instance, is known to have battleships capable of making the same journey in just over a month and scouting vessels that can do it in two weeks.
While all races have access to FTL travel, very few have faster-than-light communications. There is no question that the Durog could speak across distances instantly, but humanity is known to have only a single unit capable of this feat, and used only for communications between Sothis Station and Earth. Most people wishing to send missives use an informal postal system that originated on Sothis station. Recognizing the value of this system, parcel carriers are given a great deal of latitude by all races and even Torm space is open to them.
For those with money, and a need for faster communications, there is an alternative. Robotic probes capable of FTL speeds in excess of full-sized ships can be hired. Human-built probes are among the fastest, and generally are able to cover a parsec of space in between five and ten days.
Like FTL technology, all major races have the wherewithal, if not the propensity, to create robots. Humanity is far-and-away the leader in the use of robots, and Earth is littered with them. Tayvaak robots tend towards artificially intelligent computers meant to assist with routine activities such as flying starships or operating machinery. Generally speaking, robots are not self-aware free-thinkers, but as Meks prove, that isn't the case everywhere.
Androids are a different matter. A uniquely human creation, they face an uncertain future. Some progressive thinkers advance the idea that they are living creatures, and should be afforded all the rights of sentient beings, while others view them strictly as machines and property that is owned and traded but never truly sentient.