Colossus

The colossus was a massive protoss robotic walker designed to destroy large numbers of weaker ground targets. An antiquated construct dating back to the Kalath Intercession, it was unique among protoss automatons in that it was built purely as a war machine, in contrast to the industrial and resource-gathering automatons that made up most of the protoss arsenal. Feared even by its makers, who held that the machines could not truly be controlled and might one day turn against them, the colossus was outlawed for generations before the war against the zerg forced its return. (Colossus; StarCraft II: Wings of Liberty)

Design and armament#

The colossus was a towering construct that strode across the battlefield on four tall, slender legs, a configuration that gave it an extremely high level of mobility. Its great height allowed it to step up and down cliffs and other steep elevations with little difficulty and granted it a dominating field of fire, denying an enemy the advantage of higher ground. Most of its mass sat at the top of the construct, so that a colossus sufficiently damaged could topple over quickly. It was primarily powered by crystals situated between its two thermal lances. (StarCraft II: Wings of Liberty; StarCraft Field Manual; Colossus)

Those lances were its weapons: one mounted on each side of the heavily armored hull, sweeping beams of superheated plasma across scores of enemy ground targets at once. Dominion field guidance called it the ultimate infantry killer. The lances suffered from limited range, a problem the protoss later addressed with the extended thermal lance. (StarCraft II: Wings of Liberty; StarCraft Field Manual)

The Kalath Intercession and the Conclave's ban#

The colossus was created purely as an instrument of war, and its full destructive power was demonstrated in the mass slaughter carried out against the kalathi. The killing appalled the protoss. In response, the Conclave outlawed the manufacture of colossi, and the existing machines were deactivated before being sealed away. Some were stored on Aiur, a number of them underwater, their crews and systems left dormant and awaiting a reactivation signal that did not come for generations. (Mothership; Colossus; StarCraft II: Wings of Liberty)

The war against the zerg nonetheless forced a reckoning with the old prohibition. In 2503 the protoss began collecting the sealed colossi using coordinates drawn from a preserver, despite lingering misgivings about returning such weapons to the field. During the Second Great War, Dark Prelate Zeratul traveled to Aiur and reactivated some of the buried colossi as part of his mission to study the body of the deceased Overmind. (Colossus; StarCraft: Ghost: Spectres; StarCraft II: Wings of Liberty)

Tal'darim colossi and the wrathwalker#

The Tal'darim unearthed a number of colossi for themselves, drawn by the promise of superior firepower. Lower-ranking ascendants often dared one another to disable and commandeer an active colossus: success granted the daring ascendant a powerful war machine, while failure eliminated a rival. During the Second Great War the Tal'darim deployed colossi on worlds such as Xil and Atrias, and later in the war used them in the defense of a xel'naga temple on Xil. Several of their machines were refitted, the thermal lance replaced with a charged pulse blaster to eliminate priority targets, and these variants were renamed wrathwalkers. (StarCraft II: Legacy of the Void; StarCraft II: Wings of Liberty)

Terror of the Dominion#

By 2505 the Terran Dominion was aware of the colossi fielded by the Daelaam. Field reports referred to the walker as "a walking skyscraper of destruction" and "the tower of death." The Dominion advised its marines to find bunkers and call in air support when confronted by colossi, conceding that even soldiers who rushed underneath a walker's legs to evade its firing angles might be crushed beneath them. (StarCraft Field Manual)

The colossus served on in the conflicts that followed. Colossi were later deployed in the Reclamation of Aiur to clear the warp conduits of zerg forces, and later in the End War they helped deactivate the shield around Cybros. Colossi developed under the Purifier program, built as the ultimate purification machines and employing more destructive incendiary weaponry than their Khalai counterparts, were later added to the Daelaam arsenal. In the aftermath of the End War, selected colossi that had served in the conflict were redesigned in a more traditionalist style to better resemble the ancient protoss war machines, a gesture of veneration for a weapon their makers had once feared to wield. (StarCraft II: Legacy of the Void)