There is no up. There is no down. Those directions have no meaning here. In front of you there is nothing but deep darkness with distant, beautiful points of light in different shades of yellow, red, blue, and white. They don't sparkle, but there's not much out here to interfere with their light, so that makes sense. All you can hear is your own breathing and the very faint sound space makes through your radio. You wonder if this is a bit like how it feels to be dead.

You use the tiny suit thrusters to turn round slowly and face the sleek, silver ship behind you. The airlock looks safe and inviting, but it's worht spending just another moment out here. You fiddle with the radio controls on your wrist, and for a moment, through the ancient static of space, you think you might be able to hear singing...

The Present Day

It's the year four thousand, two hundred, and forty-something. Humanity is spread out across the galaxy, with colonists sent further afield. No word has been received from them yet.

FTL is achieved with spatial bubbles. While an object cannot travel faster than the speed of light, space itself can, so an object stationary in space is moved at faster-than-light speeds by moving the space it inhabits. As a result, relatively large objects can be moved with relatively little energy.

The galaxy is fairly calm, but interplanetary skirmishes and the ever-present threat of piracy mean that all FTL travellers must take care. Furthermore, unguided FTL is unsafe, so most ships make short hops from beacon to beacon separated by no more than a few tens of parsecs.

The Council of Three Thousand

The Council of Three Thousand is a council of representatives from the three thousand most powerful sentient species in the galaxy. The council mediates between its member species and their various nations and territories, and tries to maintain peace within the galaxy on an interstellar level. It is largely successful, although border disputes and piracy are still rife.

The species of the Council can be broken down into four groups. The Elder Races, the CATG Diaspora, the Younger Races, and the Synthetic Races. There is also a theoretical fifth group known as the Precursor Races, but thay have not been verified yet.

The Elder Races

The Elder Races were the first species to emerge onto the galactic stage. By human reckoning, they mostly developed FTL travel between 5,000 BC and 1,000 AD. Some of them are carbon-based and some aren't, but there are no large-scale shared characteristics between them.

They tend to view all of the other species in the galaxy as dangerous, foolish upstarts.

Chzir

The Chzir are the oldest of the Elder Races, excluding potential Precursor Races. They were the first species to develop FTL, and they were the founders of the Council. They are tall, long-limbed creatures with three legs and three arms. They have a mouth at the top of their head that opens in a threefold trefoil pattern. They have three eyes, each at the base of a jaw. They are based entirely around threefold symmetry, and this is reflected in their architecture and engineering. The 'front' of a Chzir is determined by their dominant hand. The Chzir do not breathe, and as such they communicate by a complex system of colour-changes.

The CATG Diaspora

Between about 1,000 AD and 3,000 AD, by human reckoning, the galaxy was rocked by a sudden influx of species discovering FTL drives or making contact with species ready and willing to trade FTL technology in rreturn for other resources. Of the hundreds of thousands of species to emerge onto the galactic stage in this time, eleven of them did not share the same body chemistry and genetic bases. All of the rest shared the CATG bases and the double-helix genetic structure. The CATG diaspora is often held as evidence of the Precursor Races. The Elder Races look down on the CATG Diaspora, and tend to work against their well-being in Council situations.

Most species in the CATG Diaspora are also a part of the AACD, the Alliance for the Advancement of the CATG Diaspora, which aims to manipulate the Council into acting for the benefit of the CATG Diaspora.

Humans

Humans (and their uplifts) are the only sentient species in the galaxy to naturally synthesise adrenaline. Adrenaline is a virulent poison to several other species, and a powerful narcotic or combat drug to many more. Humans are known for their ability to dissociate their expectations from their reality, and their unpredictable natures. Humans are known for being reliable allies, but vicious and cunning enemies, with a penchant for creative violence. Captains of merchant vessels often prefer to have a human or two in the crew in case of pirates.

Humans are seen as exceptionally superstitious, and nowhere is this clearer than in the proliferation of Phantom Astronaut stories humans love to share.

It is generally agreed that, despite their significant and worthwhile contributions to technology, art, and culture, equal to that of most other species, by far and away the greatest thing humans have contributed to the galaxy is the Python 9 programming language, which successfully became a universal standard and is generally considered the beginning of the end of the Compatibility Wars.

Furthermore, humans are highly adept at moving in microgravity due to their primate ancestry.

Notable humans include Hod Truss, Achenar Thomas, and Lyrae.

Kiritsk

Kiritsk are similar to Terran centipedes, but much, much larger. An adult kiritsk can grow up to ten metres long with twenty legs and mandibles that can slice through steel bulkheads. They have eight compound eyes and a pair of soft, feathery feelers on their head-segments. They have a small pair of dextrous little limbs below the mandibles, which are used for a mixture of communication, feeding, and fine manipulation. They range in colours from purple to brown, with beige and red being other popular colours. Despite their size and terrifying appearances, kiritsk are exceptionally social and tend to work well in groups. They are carnivorous, and tend to prefer to feed off carrion rather than fresh meat.

Kiristk are large and powerful, and prefer gravity of about 0.7g, but struggle to operate in microgravity.

Notable kiritsk include Ketki.

Irevit

Irevit are large, powerful creatures that bear some resemblance to Terran yaks. They grow to about twelve feet tall and have eight limbs. Their upper four limbs are long, powerful arms with surprisingly gentle, dextrous fingers and hairless pads on their palms and fingers. Their upper hands are a bit bigger and heavier than their lower hands, and are more for defense and heavy lifting, while the lower hands are a little more delicate and are used for fine manipulation. They have four long, powerful, relatively slender legs ending in glossy brown hooves, and their bodies are covered in thick, shaggy brown hair. They have short, brooad snouts filled with flat teeth and bearing broad sensitive nostrils. They have big, brown, soulful eyes. They have a pack mentality, and due to evolving on a garden world they tend to have a relatively peacable attitude and outlook on life.

Irevit are much bigger and heavier than most other sentient species, and prefer high-oxygen environments between 1 and 2g. They struggle to operate in microgravity

Notable irevit include Sholt Komba.

Cryza

The Cryza all have six limbs, a hardened carapace, and a vertical mouth that opens out into a circular orifice lined with sharp teeth. They have two eyes, one above their mouth and one below. They tend to come in shades between olive-green and glossy cream. Cryza operate in a caste system and prefer high-oxygen, 0.9g worlds. They tend to have two fingers and a thumb on each hand.

Warrior Caste

The Warrior Caste of the Cryza are huge creatures, approaching ten feet in length. Their lower arms retain their functionality as manipulatory appendages, but with heavy, brutal, digits. Their upper arms have lost their functionality and instead have two long, sharp bone blades roughly analogous to a war-pick. Cryza warriors are mostly vicious soldiers, but also work as pilots and gunners in the Cryza navy, as honour guards to Cryza officials, and as guards in civilian establishments.

Notable Warrior Caste Cryza include Kzplth.

Maker Caste

The Maker Caste tend to be somewhere between five and six feet in length. They tend to be a little short-sighted, but they're a lot more agile than the Warrior Caste. The Maker Caste mostly function as engineers and builders, but they are also acceptable scientists, artists, and designers. They tend to have long fingers and lean limbs to allow them to reach into delicate spaces.

Negotiator Caste

The Negotiator Caste serve not only as negotiators, as their name implies, but also as xenopsychologists, translators, mediators, and sociologists. While they look a lot like more delicate versions of the Maker Caste, they have more versatile mouthparts than the other castes and can speak a huge number of languages comfortably.

Noble Caste

Cryza of the Noble Caste tend to be about eight feet in length, apart from the queens whose abdomens are significantly larger than even a Warrior Caste. They have long, sharp digits and large, powerful eyes. Their voices carry over great distances and their carapaces are ornate and flared to inspire humility in the other castes. They are the scientists, clergy, ministers, and officers of the Cryza.

Mongrels

Inter-caste breeding is strictly forbidden in Cryza society, but the fact remains that all of the Cryza are sentient creatures and capable of making their own decisions (no matter what the Noble Caste tells them), so occasionally some Cryza are born who don't fit into a single caste. They can be any size from Negotiator to Warrior, and exhibit any of the specific traits of the castes depending on their parentage. Their are rumours of egalitarian Cryza colonies out in the Halo stars where there are no castes and all Cryza are more versatile and adaptable.

The Younger Races

The Younger Races are the non-CATG species that developed FTL technology either during or after the CATG mass-emergence. They are looked down on by the Elder Races, and held in friendly suspicion by the CATG Diaspora.

Mothruun

The Mothruun are long, sinuous, scaled creatures with a conical, wedgelike face with an armoured frill covering the back of their necks. They have six limbs, covered with scales in varying shades of purple and mauve, each ending a clawed hand.

The Synthetic Races

The Synthetic Races are the species that have been engineered or uplifted by another species in the galaxy. They often struggle to make others take them seriously, despite the fact that some of them are older than the CATG diaspora.

Uzanti

Uzanti are a little taller than humans, but rarely much larger than seven feet tall. They are broad, four-limbed, bipedal creatures with large, undifferentiated heads. Their mouths are wide, approaching as wide as their shoulders, and filled with curving teeth. They have eighteen cyan small eyes in clusters of three around their mouth.They have silver blood, and skin that varies in colour between dark purple, vivid acidic green, lemon yellow, electric blue, and hot pink, in mottled patterns that vary with age, temperature, mood, and other factors. This is all due to the superheavy elements in their natural chemistry, which also allows for enormous amounts of energy stored in their bodies. Uzanti are capable of channelling this chemical energy into electricity through a number of connected organs in their skin. With practice, they are capable of powering surfboards and other shipboard systems. Uzanti metabolise primarily through high-energy photosynthesis based on gamma and cosmic radiation.

The uzanti are a strange outlier in terms of Synthetic Races, in that no one has come forward to claim responsibility for their creation... and been able to back it up.

Uzanti are used to 3 or 4g planets, although they are comfortable with higher. They require specialised breathing apparatus as they breath chemicals that are difficult to synthesise and occur rarely in nature. They are capable of operating in microgravity with some efficiency, but can't quite match humans.

Notable uzanti include Yaval Ti and Kevi Pyo.

Corvidae

The Corvidae are not actually a single species, but in fact a collection of about forty species. Crows are some of the most intelligent non-human creatures to have evolved alongside humans, and when humans were introduced to the technology used by other species to uplift creatures, they first tested it on chimpanzees and crows.

Corvidae are generally accepted as members of society, but often have trouble navigating environments built for larger species.