Aurunin Lore Dump
Unorganized dump of random lore thoughts I have about my Aurunin species. This page somewhat regularly updated if/when I have new ideas.
They're an open species and you're free to ignore all of this for your own characters if you want, these are just my personal ideas.
Some more (SFW) art pieces showing Aurunin
Last updated April 15, 2026
Evolutionary History & Life
The species evolved on the twilight/dark side of a tidally locked planet, that is cold due to being perpetually dark. The hot side of the planet was too hot to be readily inhabitable, and they evolved more on the dark side rather than purely on the terminator[1] because of the high winds present at the terminator itself (due to convection between the hot and cold air). They still live in the strip around the terminator though, as the middle area of the dark side is nearly as uninhabitable as the light side is.
They primarily live in underground cities, developed from the natural caves life originally evolved in, due to the relatively extreme conditions on the surface.
They have a relatively small population due to the harsh conditions they evolved in. Even after developing space travel and colonizing much more habitable planets, they still have an orders of maginitude lower population than any other species and tend to form close communities.
Echolocation
Their primary sense for observing the world is echolocation. Their echolocation gives them a full three-dimensional view of their surroundings like stereoscopic vision does; although naturally there's a limit to how far they can “see” due to properties of sound propagation (and the precision of their echolocation degrades with distance).
The “images” they percieve are depth-map-like[2], as distance is the primary information echolocation gives.
They echolocate using noises/calls akin to bats as well as other noises like clicks, using both frequency-modulated and constant-frequency calls when context-appropriate (FM for fine detail perception, CF for distant viewing and detailed velocity).
See also: animal echolocation.
They can also do “passive” echolocation using noises produced from other sources, that is less detailed but allows them to avoid making noises themselves. It requires line-of-sight (line-of-hearing?) to the source, and they can compare the timing between the noise directly reaching them and any reflections it made to get rough echolocation data.
When around other species, they tend towards heavier reliance than normal on passive echolocation and echolocation calls in ultrasonic frequencies to minimize potential disturbance on other nearby sighted species that may not be used to aurunin calls.
Culture & Psychology
Body Language
The have some limited body language, that are naturally all obvious enough to be visible via echolocation; although they depend on body language much less than sighted species as they don't necessarily constantly echolocate throughout a conversation to percieve the body language. They don't naturally have many facial expressions as they are usually too subtle to easily pick up on, although they have a limited amount. They also have some more subconcious behaviors that can serve as body language to other species, but are just mannerisms that weren't evolutionarily used for communication.
Aurunin that work regularly with other species typically take classes to learn how to conciously mimic body language and facial expressions of other species, to more easily communicate their emotions and tone.
Spoken & Written Language
Their languages have distinct terms for “hearing” versus echolocation, as despite both technically using the same senses, the sensory inputs and the way they percieve the information is very different so it justifies distinguishing them in a similar way sighted species distinguish vision and hearing. Although naturally the lines between hearing and echolocation are much more blurry as limited spatial information is still gained through normal sound listening.
They mostly use a braille-like writing system, based off of phonetics since they developed writing comparatively late compared to sighted species. But they can also read engraved/reliefed text using echolocation if it's large enough, and they have a secondary writing system desgined for this that's very angular, being designed for stone engraving (like the Latin alphabet used to be), that's used on signage and such.
Relationships
They form lifelong pair bonds[3] that are much stronger than what would be formed by humans or many other species. Once they fully form a bond with their mate, they'll universally stay together for their whole lives (with about an even split of finding a new mate or staying alone if one of them dies).
A plurality of mated aurunin are simply fully monogamous. However, surprisingly, the fact they form such strong social bonds actually causes a large proportion of aurunins' sexual practices to be fairly polygamous. They are generally fine with their mate and themselves having any number of long- or short-term sexual partners, as the thought never crosses either of their minds that their mate having other relationships would compromise their own relationship with each other. Certainly no worries about their mate leaving them for someone else, which is just not a thing with how aurunin psychologically bond with each other.
Naturally there are outliers that have an unusual psychological makeup that don't form full pair bonds, but the *ability to* form pair bonds is near-universal and outliers are extremely rare.
Clothing
They typically do not wear clothes except for utilitiarian purposes, e.g. for weather protection. The most common item of clothes an aurunin on their homeworld would wear is shoes, just for general foot protection and due to cold stone floors underground.
Naturally, aurunin that interact with other species often typically wear clothing all the time, rather than only when necessary.
Misc. Cultural Elements
Although their echolocation is extremely sensitive, they're still very touch-focused (and cuddly…) because that is a lot more important when one doesn't have the breadth of body language and nonverbal communication that sighted creatures have.
Due to being digitigrade, they culturally tend to not stand upright for prolonged periods of time unless necessary due to the leg exertion required.
Technology
Aurunin Interface Devices
They first developed tactile displays like braille displays for viewing textual output of computers, which remain very common and convenient. They also historically had displays that would physically manipulate a sound-reflective surface to allow viewing images with echolocation.
However, they also fairly rapidly developed VR-like systems that simulate echolocation to produce full images. They can simulate active or passive echolocation, either by making it seem like a sound is coming from the viewer and then producing fake modulated reflections, or just producing plain+modulated sounds emulating passive echolocation.
They later also developed displays that allow viewing without needing any headset, using a flat a screen-like area with an array of speakers. They emulate passive echolocation by producing a signal from one location and the array producing modulated signals as if it was reflected, to make it seem like the display surface is textured. They have limited ability to produce depth and are primarily only used for public kiosks or such, where expecting every viewer to put on a headset (or connect their own) would be undesirable.
Sensory Augmentation
It's fairly common for aurunin to use headsets that provide augmentation to their echolocation, particularly when working with sighted species. The technology was largely originally developed for spacesuit helmets, but was commonly adopted as just a general augmentation headset.
Some headsets simply provide more sensitive microphones with amplification of slight echos to allow longer-range and more sensitive echolocation. However, the more common kind uses LIDAR to create echolocation-like images, but with much longer range and that can function in vacuum, or without requiring making noises when in an atmosphere.
More advanced units also have cameras sensitive to various wavelengths, to allow a variety of luminance-based visualizations as well as depth-based visualizations. (n.b. that they wouldn't just use plain cameras all the time because to them percieving luminance images, while comprehensible, would look very odd to them and not be desirable as the primary visualization. Similar to how using a VR headset that exclusively displays depth maps[4] would feel for humans.)
Most of the complex sensors (particularly cameras) are just mounted facing foward on the flat sloping part of the helmet/headset, just because it's a lot of hardware. However, most units have one or tow primary LIDAR cameras on a small separate arm that can change where it's viewing, often synchronized to match ear movements, to make operating the primary visuals more intuitive and convenient.
Space Travel
They discovered astronomy, and even just distinguishing the concept of space distinct from “a big void”, late compared to other species, as they had to develop light-based sensing to discover stars and other planets. However, after they first discovered it, they were very curious and devloped (correct) theories about astronomy and then advanced space travel much more rapidly than any other species did.