Star Wars: The Old Republic will launch its sixth major update since Knights of the Eternal Throne at the end of November. It will include an additional operation boss fight and another flashpoint to continue the Alliance traitor storyline. And even though the update is well over a month away, we know that storyline will continue on the Chiss-occupied world of Copero, once again tying author Timothy Zahn to the game.

But who are the Chiss, and why are they so important to the Star Wars universe? Besides being the species of the Imperial badass Grand Admiral Thrawn, the Chiss are very much a mystery to the galaxy at large. However, thanks to the many books, comic books, and video games, we do know a thing or three about this secretive species. Here are 10 things that you need to know before jumping into the new content.

Their native language is Cheunh

Although it’s probably not surprising that an isolated species has its own language separate from the rest of the galaxy, what you might not know about the Chiss language of Cheunh is that it can be spoken only by the Chiss species. We don’t exactly know what it sounds like because it’s never spoken in any of the movies or television shows; we do know that there are intricacies with the language that non-natives find too complex and nuanced to speak properly. It was a matter of pride for the Chiss that they could speak a language that other species could not.

Their shortened names are called core names

On the subject of language complications, let’s talk about Chiss naming conventions. Consider the very first Chiss character that we see in Star Wars to get the idea of how Chiss names work. Mitth’raw’nuruodo was created by Timothy Zahn and was a Grand Admiral of the Galactic Empire. We know him better as Thrawn. “Thrawn” is his core name or common name. Mitth is his immediate family name, and Nuruodo is his clan name. Raw is his given name. However, core names are usually derived from by taking the last letter of his family name and combining it with the first letter of his clan name. There are exceptions to this norm like Sev’rance Tann (whose common name was Sev’rance) and Moff Fehlaaur’aitel’loro (who was called just Fehlaaur).

They do not display feelings openly

Possibly this is because Chiss were usually very calculating, or maybe it was a cultural taboo, but outside of the immediate family Chiss rarely showed any strong emotion. I don’t want to say that Chiss were like Star Trek’s Vulcans, but there are a lot of similarities. Chiss were highly logical and calculating. They were also considered to be rather cold. However, unlike the Vulcans, Chiss didn’t completely forbid emotions; they simply didn’t show them very often.

They are full adults by 14

Chiss also matured more quickly than most humanoid species. By age 10, Chiss were typically fully matured physically and were considered full adults by age 14. Middle-age didn’t really hit most Chiss until they were over 50, and 80 was considered venerable.

Their eyes glow depending on oxygen level

As you might have seen in game, Chiss eyes are completely red. Although in new canon, Thrawn’s eyes have a pupil, classically and in Star Wars: The Old Republic, the Chiss have no visible pupils. However, as far as anyone can tell, they function very similarly to human eyes with one exception: They tend to glow red when they have high amounts of oxygen pumping through their veins.

They are highly xenophobic

As you might have guessed by the fact that few outside species know much about them, the Chiss are very xenophobic. It’s never really explained why the Chiss are that way, but I would venture to guess that it has more to do with Chiss superiority than it has to do with actual fear of other species. Very few if any outsiders know where the Chiss homeworld of Csilla is, and as of right now, the new world of Copero is the only one we have seen in a video game.

They might have come from an old human colony

For such an isolated species, they resemble humans awfully closely. If we dive into deep lore, we find that it’s possible that Chiss might actually have been birthed by a long-lost human colony.

They do not use the Force (openly)

Chiss are very secretive about how their society works, which is hopefully be obvious by now, but what’s strange is that in all of canon we have seen only two Force-wielding Chiss. And they both were outsiders from the Ascendency. Sev’rance Tann served the Separatists under Count Dooku, and Jedi Nuru Kungurama was a Jedi, which by definition meant that he didn’t live among the Chiss.

They have nine ruling families

We know at the time of Thrawn that there are nine ruling families in the Ascendancy. To most Chiss, the Ascendancy is very oligarchical. Among the ruling families, things appear to be very democratic. The ruling families usually oversee a specific segment of Ascendancy life. For instance, House Csapla oversaw colonial affairs, agriculture, and resource distribution. Nuruodo was the House that oversaw military affairs. Science and communication were handled by the Inrokini family. And Sabosen was in charge of health, justice, and education.

The Chiss Ascendancy was the only ally of the Sith Empire

Lastly, let’s talk about the relationship between the Chiss and the Sith Empire. We know that when the Empire first met the Chiss, long before it traveled back into known space, the Emperor cut a deal with the Ascendancy, making the Chiss society the first and only nation that the Sith Empire ever actively allied with instead of conquering. We still don’t exactly know why that is, but maybe we will get hints in this new flashpoint.

There are a lot more little facts about the Chiss that I didn’t mention here, but these are some of the most important. What are your favorite Chiss facts? Are you looking forward to actually getting to visit a Chiss world? Let me know your thoughts in the comments.