Psionics

Psionics was the psychic power that ran through all three of the galaxy's dominant species and shaped much of the history of the Koprulu sector. Among the protoss it was the foundation of an entire civilization, expressed through the communal link of the Khala and the shadow energies of the Void. Among the terrans it was a latent gift that left them only a few steps from becoming a formidable psionic power, and which made them valuable to the zerg. For the Swarm, psionics was both the medium of its communication and the means by which it was controlled.

Psionics among the protoss#

For the protoss, psionics was not a rare talent but the basis of their nature. All protoss eyes glowed with latent psychic power, and when a protoss was particularly emotional, streams of energy could pour from them much as a terran might weep. Their psionic abilities ran further than those of terran ghosts: they were natural mind-readers who had to learn to filter the thoughts of others and to block and release their own minds, and they could think through many lines of thought and memory in the span of a second. With their power they could shield themselves, charge their tools and weapons, and materialize, manipulate, or meld matter, though some of these feats, such as the creation of shields, could be performed without technological aid only by a small minority.

Protoss communicated psionically, either through emotionless "speaking" or through the nerve cords that carried emotion and formed their racial gestalt. They spoke a mental language, Khalani, in telepathic bursts, and could even reach across interstellar distances with the aid of psi-link spires or interface directly with terran video systems. Psionic power also tied the protoss to their dead: through the Khala, and with the help of the Templar Archives, a protoss could sense the memories and experiences of fallen warriors, though only preservers held full access to this knowledge.

The Khala and the Void#

Protoss psionics flowed through two great channels. The Khala, founded by Khas at the end of the Aeon of Strife, was a communal link that bound its adherents in shared emotion and granted each protoss an enormous reserve of psionic energy. Its discipline was required to control the most dangerous abilities, the psionic storm chief among them, and during the Aeon of Strife the untrained rogues who would become the Nerazim inadvertently unleashed such storms on Aiur when they could not control their powers. The Khala measured strength in levels, fifth-level adepts being considered extremely powerful, and its fortitude protected its followers from assimilation by the zerg.

The Nerazim, having severed their nerve cords and cut themselves off from the Khala, drew their psionic energies from the Void instead. These shadow energies were harmful to the zerg cerebrates and the Overmind because of the similarity of the cosmic forces they wielded, and the Dark Templar regarded their powers as the "true gifts" of the protoss, wider than the narrowed power of the Khala. Their abilities included what was described as bending light and merging with shadows, the cloaking craft that Adun had taught them. Wielding the Void and the Khala simultaneously granted a protoss incredible power but risked burning them out like a star, and only a few, among them Adun and Tassadar, could do it. Both the Khala and the Void protected the protoss from zerg infestation.

Terran psionics#

The terrans were a young species, physically inferior to the elder races, but they carried psionic potential and stood only a few steps from developing into a formidable psionic power. That potential could be measured, refined, and weaponized: the Terran Confederacy experimented with psi emitter technology during the Great War, and the Sons of Korhal later used stolen psi emitters to lure the zerg to Tarsonis and destroy the Confederacy. The most powerful terran psychics, the ghosts, wielded telepathic and telekinetic abilities, while weakly psychic terrans called wranglers were employed to seek out other psychics.

It was the terrans' psionic value that first drew the zerg to them, for the Overmind ordered the assimilation of the species precisely because their psionic potential was needed to fight the protoss. One terran, Sarah Kerrigan, was a ghost of exceptional power whose psionic strength the Swarm sought to claim when it captured and remade her as the Queen of Blades. A terran ghost once theorized that humans could become a better people were they able to share a psionic link as the protoss did, though terrans, far more attached than the elder species to private thought and personal freedom, were judged unsuited to the unity the Khala brought.

Psionics and the zerg#

For the zerg, psionics was the ordinary medium of communication: members of the Swarm communicated largely through psionics, with only the higher command strains able to process and understand vocal commands, a balance that shifted toward more vocal communication only after the End War. The zerg could sense psychic power and, being acutely sensitive to it, often sought it out, sometimes responding to it so strongly that they rendered themselves temporarily beyond the control of a leader; this sensitivity reached further than that of the terran wranglers. The amount of psionic control exerted over a zerg force shaped its intelligence, and without that control the zerg became little more than animals, the feral zerg who attacked everything on sight.

The Overmind, the cerebrates, and later Sarah Kerrigan and her broodmothers held the Swarm together through this psionic command. The United Earth Directorate turned the principle into a weapon during the Brood War, deploying a psi disrupter to fragment the zerg arrayed against it, and the Terran Dominion "lobotomized" zerglings as early as 2500 to cut them off from the Swarm and use them to hunt psychic terrans. Decades later the evolution master Abathur bred the chitha, psionic zerg whose strong presence could disrupt communication and command nearby zerg, demonstrating once again that for the Swarm, psionics was both the source of its unity and the means of its undoing.