The main protoss cultural groups are the Khalai, who adhere to the communal Khala, and the Nerazim, who reject the Khala. In addition, another branch of the protoss separate from the Khala called the Tal'darim lives in various places in the galaxy.
The protoss are an ancient race, and they consider themselves to be the "firstborn" race of the universe.
The protoss were discovered by the xel'naga on Aiur, a world the xel'naga had previously engineered. The xel'naga, who were nearing the end of their life cycle, were in need of a race to achieve purity of form and intrigued by their mental connection, chose to use the protoss. Pushing the evolution of the protoss, the purity of form was achieved and the xel'naga eventually descended to Aiur. The protoss, who revered the xel'naga as gods, learned much from them. However, these discoveries divided the protoss, causing their psychic links to disappear and wars to break out amongst them. The xel'naga left the planet as the protoss fell into the Aeon of Strife.
Approximately 1500 by terran reckoning, the Conclave attempted to exterminate rogue heretics who had deliberately cut themselves off from the Khala and would later become known as the Dark Templar. They ordered Executor Adun to execute them, but Adun refused, instead teaching the rogues to hide from the Conclave. Eventually the rogues lost control of their powers, alerting the Conclave. They were secretly banished on a xel'naga ship.
By 2499 the protoss became aware of a xenomorphic threat, the zerg, another alien species also created by the xel'naga. The zerg were attacking the terrans, a species which had traveled to the Koprulu Sector two hundred years previously. The Conclave dispatched Tassadar and a force of protoss to destroy the infestation by purifying the infested worlds.
Tassadar's force failed in its mission, and the remnants traveled to the new zerg homeworld, Char. There, Tassadar struck an alliance with the Dark Templar prelate, Zeratul. They discovered a weakness in the zerg command structure which could be exploited only by the Dark Templar, and clashed with their new leader, Infested Kerrigan. Meanwhile, the majority of the zerg force traveled to Aiur. The protoss were losing the battle, but when Tassadar brought Zeratul to Aiur, a protoss civil war broke out between Tassadar's followers and the followers of the Conclave. Eventually Tassadar's faction won. Unimpeded by the Conclave, Tassadar's followers attacked the Overmind itself. Tassadar died during the battle. Seventy percent of protoss on Aiur were killed.
The protoss fled to Shakuras, followed by a zerg faction. The protoss destroyed the renegade zerg, saving themselves but advancing Sarah Kerrigan's aims. With the assistance of her enigmatic minion Samir Duran, she would later force the protoss into destroying the second Overmind for her, making her the sole leader of the Zerg Swarm. As the protoss attempted a revenge strike on Kerrigan, Duran abandoned her to conduct protoss/zerg hybridization experiments, which were discovered by Zeratul. The latter exiled himself for several years following the discovery.
...is tall, dark and ugly?"
Protoss are about two meters (seven feet) to three meters tall and have two glowing eyes that blink normally, digitigrade legs, semi-permeable skin covered in scales, four digits on their hands (of which two are thumbs) and toes, broad chests and shoulders, and narrow waists with slim midsections. Extending back from the crown of the head, protoss have a bony crest. Beneath it, emerging from the back of the head, are the nerve cords, allowing them to access their racial psionic gestalt. This gestalt is the basis of the Khala.
The xel'naga considered these beings to have purity of form as the protoss are incredibly adaptable to harsh natural conditions and climates, and their strength and speed were unparalleled amongst the other races known to the xel’naga. Protoss even have sharp claws, which can be deadly weapons if a protoss is caught unarmed.
Protoss derive sustenance from light, capable of living off moonlight (reflected sunlight), and can go without light for extended periods of time. What little water they need is absorbed through the skin. The Dark Templar modified themselves biologically and used other techniques to survive on the formerly lightless world of Shakuras.
The protoss used to hunt, but they did so to collect the blood and hides of animals for various purposes, not for sustenance.
Protoss hear and smell through their skin, and it is believed that their primary sense is sight. Protoss have a sense of smell sharp enough to identify other protoss and see very well at night. A protoss' skin color may change in response to changes in its emotions. They are bereft of mouths, noses, or visible ears and are without a sense of taste. They possess three hearts.
Protoss sleep and dream in a manner similar to humans.
Protoss are not a prolific people and the xel'naga even developed an artifact, the Kassia crystal, to counteract this. The population of Aiur, however, had reached billions. Before the Fall of Aiur, the protoss population was in decline due to systematic extermination; the protoss were passing away from sheer age. Their numbers have been further reduced through conflict, and their population continues to decline.
Protoss blood is blue or purple. As in humans, coloration is considered a sign of ethnicity, with each protoss tribe having a specific subtly differing hue or typical pattern of markings associated with it.
As with terrans and zerg, protoss genetic material consists of DNA with helix strands. There is evidence that the protoss have yet to unlock their full genetic potential, but this theory died along with the Protoss Advance/Experimental Facility.
Protoss possess a body part called a phylar, which may be held by their hand.
On the battlefield protoss warriors are known to fight with tremendous power and grace, but despite the chaos they inflict on their enemies they are capable of being mortally wounded. When a protoss nears death, their foes often bear witness to a startling flash of bright light as the protoss warrior seemingly disappears. Primitive races are known to quail in superstitious fear upon seeing this, but it is actually another aspect of protoss technology at work rather than any sort of supernatural feat.
Protoss armor is typically equipped with a complex teleportation mechanism that can detect when its wearer is grievously injured and automatically teleports the warrior to the nearest safe haven. This of course is dependent on the mechanism being fully functional, as there is the risk of being damaged during combat.
Those protoss who are too badly injured after the battle but still wish to continue fighting are placed within the shell of a dragoon or immortal, which allows them to serve their brethren on the battlefield. The choice is left to each individual protoss; whether to continue service or join with their ancestors in the Khala.
Protoss have been described as "devastatingly intelligent", but their thought processes work very differently than those of terrans.
Protoss are natural mind-readers. Protoss must learn to filter the thoughts they read and filter (or block) the thoughts that they release (which would prevent other protoss from reading their minds). The ability to block thoughts is compromised by the Khala, which prevents the protoss which follow that philosophy from hiding from each other. During the Aeon of Strife, Protoss regularly used their mind-screening abilities to ambush each other.
Protoss can use their psionic abilities to shield themselves, charge their tools and weapons, and to make, manipulate or meld matter. At least some of these abilities can only be used by a small minority of protoss without technological assistance (such as the creation of shields).
Protoss can sometimes access memories and strands of experience from protoss who have died and entered the Khala, but only preservers have full access to this knowledge. Protoss warriors can learn from the spirits of fallen warriors at the Templar Archives.
Protoss can communicate telepathically with each other. They can do so through "speaking", a method that transmits little or no emotional content. Using their nerve cords they can also communicate in a manner which enables them to sense each others' emotions, a key part of their psionic gestalt, the Khala. During the Aeon of Strife this ability had fallen into disuse, but was restored by the mystic Khas. Protoss who follow the Khala use both methods of communication. Dark Templar ritually sever their nerve cords, which prevents the emotional link.
Protoss can create a special kind of mind-meld deep within the Khala, where no one can lie. Protoss performing this kind of mind-meld hold up their hands and face their palms to each other; both palms softly glow. This kind of communication was also possibly held between Executor Adun and Raszagal, the latter not following the Khala.
Protoss "speak" a language called Khalani, communicating through telepathic bursts. The privacy of the conversation is up to those involved on it. Even through communication, pain can be caused via this telepathy via mental spikes. Terrans exposed to protoss communication often hear nearly meaningless sounds. However, at least some protoss have the ability to "translate" the thoughts into a form which a terran can understand.
The protoss of the Aeon of Strife did not understand the concept of non-psionic communication. Khas effectively (re-)created the concept of reading and writing, a necessity for translating some xel'naga relics.
In addition to telepathy, protoss possess a degree of body language used in conveying feelings, intent, etc. For instance, a bob of the head and movement of a protoss' nerve chords is a sign of contempt. Bowing of the head, shaking and/or mottling of the skin is a sign of emotional distress.
Protoss culture is built around core philosophies that have been rigidly adhered to for over a millennium. As such, it is difficult for their society to adapt to changing circumstances. The integration of Khalai and Nerazim is a case in point in different cultural values.
Khalai culture has its roots in the Aeon of Strife, the period of chaos following the retreat of the xel'naga. At the end of the Strife, the protoss were reunited under the precepts of the Khala ("Path to Ascension") as promoted by the mystic Khas. The Khala took advantage of the natural psionic communal link and established a caste system. Protoss can be fanatical when it comes to their religious beliefs.
Not all protoss embraced the Khala. Many outcasts, eventually known as the Nerazim, were later banished from Aiur. Yet other outcasts, the Tal'darim, use drugs to cut themselves off from the Khala.
Female protoss rarely attain positions of power, except among the Nerazim. They are rare among the Templar Caste and were never part of the Conclave. Many protoss have a prejudice against female terrans, as the only one they've had much contact with was Kerrigan (contrasted to Jim Raynor).
The protoss are considered a "warrior race", although they were not constantly at war. They trained incessantly for combat, however, and prior to the Great War warred with the kalathi and "other types" of protoss. Protoss have a strict code of justice and honor, and strongly believe in their responsibility to enforce it. They strive for glory in battle.
Protoss have a mental language, Khalani, and a written language, which the Nerazim maintained. Khalai can communicate wordlessly due to the properties of the Khala, while Nerazim must voice their words vocally.
The protoss as a whole once worshiped the xel'naga as gods. In the present day, various protoss have also referred to the xel'naga as gods, and the Tal'darim have taken a hardline approach to worship of the xel'naga as deities. The Skygeirr Tal'darim branch worshiped Amon as a singular deity.
A number of protoss are highly regarded by both Khalai and Nerazim, and have become associated with honorifics (e.g. "en taro"—"in honor of"):
- Khas – A prominent figure in protoss society, he was the charismatic and spiritual leader who brought an end to the Aeon of Strife by using ancient xel'naga artifacts, the khaydarin crystals, to unite the warring tribes by calling them into a communal telepathic matrix. The belief that this was necessary for the protoss to survive became known as the Khala, and is followed by almost all protoss factions. The Path of Khala is the sole and dominant religion in the society of the protoss of Aiur, and societal rank (for example, Templar, Judicator) and honor are linked with Khala.
- Adun – Another well known figure in protoss culture, he is honored by Khalai and Dark Templar alike. A powerful warrior in his time, he was charged with the extermination of the rogue tribes by the Conclave. Unable to bring themselves to slaughter their kin, Adun and his troops attempted to hide the heretics. Though he failed, he would be known as a savior to the Dark Templar, and would gain similar status on Aiur after the myth of the heretics spread, revealing that he "saved" Aiur from the heretics and their "anarchist" ways. The phrase "En Taro Adun" is used by the protoss as a formal greeting or farewell, and also serves as a battlecry, while the Dark Templar use "Adun Toridas" in a similar fashion.
- Tassadar – He led the Koprulu Expeditionary Force during the Great War. The subsequent reunification of the Khalani with the Dark Templar began with his befriending of Zeratul. This alliance allowed the protoss to slay cerebrates and the first Overmind. Tassadar sacrificed himself to kill the Overmind. For his heroic example, he serves as a contemporary example of protoss virtues. Some Templar, notably Artanis, Selendis and Zeratul have taken to saying "En Taro Tassadar".
The extent to which the protoss have been a unified people has waxed and waned over time. Originally tribal based, the protoss settled under centralized rule with the coming of the xel'naga, only to revert back to tribalism in the Aeon of Strife, only to once again be unified after thousands of years. Under the Khala, the Khalai formed the caste-based Protoss Empire while those who refused to submit became the outcast Nerazim.
In the aftermath of the Brood War, both lines of protoss were united under the Protoss Protectorate/Daelaam. However, internal tension once again led to tribalism and their civilization fractured.
- Main articles: Protoss Technology Listing
Protoss technology is a blend of psionics and mundane technology and has shown itself to be far more advanced than many other species of the galaxy, including humanity. They have been referred to as "the most technologically advanced race in the universe," and their warriors are "the best trained in the galaxy."
Some protoss technology requires vespene gas as a catalyst. Protoss utilize cybernetic technology to save lives, and bolster their warriors' prowess. Battlefield communications between protoss are efficient. The use of energy for defensive purposes is a standard protoss practice.
Protoss armor contains teleportation technology which whisks the warrior away to safety when they are injured to the point of death. Injured and crippled protoss can be transformed into cybernetic warriors.
Protoss pilots are an integral part of their ship, and using it drains their energies. Protoss aerospace craft utilize anti-gravity technology to keep them airborne when operating within a planet's atmosphere.
The protoss developed powerful crystal technology and incredibly powerful weapons of war, such as the colossus and the mothership, and could develop more powerful technology if they wished. The protoss limit their use of technology, as they are frightened of what they could do with it and feel they have perfected a slow but steady and methodical system of technological development. The longevity of protoss history has allowed them to develop incredible weapons of war over the course of it.
- "Protos" in Greek means "first". This name is supposedly given because the protoss were the first semi-successful xel'naga creation. The protoss were later deemed a failure by the greater species, leading to the engineering of the zerg.
- In StarCraft online culture, the protoss are often referred to simply as Toss (or P or Pro or PTo by some Korean players); amongst more experienced players, it's usually abbreviated to simply P.
- The protoss bear similarities in their "look and feel" with the draenei of Blizzard Entertainment's Warcraft universe.
- All protoss names undergo careful consideration, as Blizzard has very strict guidelines as to how a protoss name should and should not look like. This is linked to a real-world dictionary of Khalani being maintained.
- While the terrans and zerg had different backstories in the first pitch for StarCraft, the protoss appear to be much like their counterparts from the end-game. In this version they were more willing to take direct action against terrans however, as demonstrated by the original Tau Ceti backstory.
- For StarCraft II, the protoss underwent an asthetics redesign, with more flowing shapes, less geometric angles and a more organic feel. This was part of an unofficial retcon on Blizzard's part, an idea that protoss structures in StarCraft II had always looked the way they appeared in the game. Early styles bore resemblance to that of the blood elves of Warcraft due to their flashy engravings, but this art style was abandoned.
- A challenge for writing protoss is that they do not possess the same kind or amount of body language as humans. The writers of Legacy of the Void watched episodes of ER, for as it per its nature as a medical drama, the characters' faces are often covered bar their eyes. Eye movement was studied in regards to how it could apply to protoss characters, as their eyes are their main conveyers of emotion. While the protoss are intended to be "unkowable" (in regards to humans/terrans), it was also intended that elements of humanity still shine through.
- Blizzard refers to the protoss as their "space samurai," or "space paladins." In Blizzard's mind, the protoss are defined by the following traits:
- Ancient, noble race.
- The Khala.
- High tech.
- Small numbers.