The Protoss are a sentient humanoid race native to Aiur. They are technologically advanced and rely on psionic abilities and cybernetics in battle. They are the primary opponents of the Zerg. The Protoss are highly religious and follow a strict code known as the Khala. The Protoss have mastered their psionic powers and were recently engaged in a devastating war with the Zerg. They have also had to deal with civil wars within their ranks.
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.
Biology
Protoss are about three meters tall and have two glowing eyes, 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 are bereft of mouths, noses, or visible ears. Two of the Protoss portraits (namely those of Aldaris and the Arbiter unit) appear to have mouths or at least folds on their faces that resemble mouths, but these "mouths" do not ever open.
Protoss derive sustenance from light, capable of living off of moonlight (reflected sunlight), and can go without light for extended periods of time. They drink water, and what little water they need is absorbed through their skins.
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.
Protoss sleep and dream in a manner similar to humans.
A Protoss' average life expectancy is about a thousand years; Raszagal, aged 1045, was considered old. Protoss under 300 years rarely have any significant political positions. Artanis, who was 262 years old during the Brood War, is considered young, despite his powerful military position.
Protoss are not a prolific people.
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 stands. 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 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.
Religion
Modern Protoss religion 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.
Not all Protoss embraced the Khala. These outcasts, eventually known as the Dark Templar, were later banished from Aiur.
Culture
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 was Infested Kerrigan (contrasted to Jim Raynor).
Combat Ability
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, 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.
