Colossus

The colossus is a tall protoss robotic unit that appears in StarCraft II. It is designed to destroy large numbers of weaker opponents.

The plural of colossus is colossi.

Overview
The colossus is an antiquated protoss war machine, dating back to the Kalath Intercession. It is unique in that it was created purely as a war machine, in contrast to most protoss automotons which are mainly created for industrial and/or resource gathering purposes. Such a trait was demonstrated by the mass slaughter carried out against the kalathi, appalling the protoss. As such, the Conclave outlawed the manufacture of colossi, and existing machines were deactivated before being sealed away in distant asteroids and uninhabited moons. The war against the zerg however, has prompted the protoss to reinstate the colossus as part of their arsenal.

The colossus is a towering construct, striding across the battlefield on four tall, slender legs which give it an extremely high level of mobility. The great height of the machine allows it to step up and down cliffs and other steep elevations with little difficulty, and gives it a dominating field of fire. The heavily armored hull of the Colossus carries two powerful thermal lances: one mounted on each side of its body. Complex focusing and targeting systems are used to pinpoint the continuous damage output of the thermal lances for optimal efficiency. As a target is destroyed, the lances are switched to a new target instantly so that a colossus' beam cuts a fiery swathe of destruction through multiple enemies with each firing cycle.

Game Unit
The colossus can be transported by the warp prism, which transforms it and other transported units into energy. A warp prism can carry two colossi.

Height and Climbing
The colossus appears to step over obstacles such as rocks, ledges and even small buildings such as the supply depot due to StarCraft II's inverse kinematics (IK) system. It can only cross shallow water, however.

A colossus is tall enough to see the tops of cliffs, enabling it to climb them without a spotter.

The colossus' height enables anti-air attacks, such as those of the missile turret, to strike it (even though it is a ground unit). Blizzard has confirmed that this is because the Colossus is so tall that it counts as both a ground and air unit for the purpose of what attacks are able to hit it. If an attacking enemy unit (such as the Thor) which can attack both ground and air units attacks a Colossus, it will use whichever attack is stronger against the colossus.

A colossus targeted by Anti-Gravity is treated entirely as an air unit and cannot attack while in the grip of the ability.

Attacks
The colossus' attacks only strike ground units.

The colossus' attack appeared (as of June 2008) as a sweeping attack, with the animation taking about a second to complete. The appearance does not reflect the nature of the attack; all targets take damage simultaneously. This attack is still temporary artwork.

The line of damage will always be based on the position the colossus attacks from, enabling a fine degree of control.

The attack does linear splash damage which is very effective against groups of units such as marines and zealots but is ineffective against buildings. It takes three colossi to destroy a marine if paired with a medivac dropship, but it can destroy groups of marines this way.

The beams do not have a "blind spot" and can strike enemies right next to the colossus.

Colossi beams cannot be stopped by a mothership's Time Bomb ability.

Development
The colossus' attack used to be a sweeping beam which would destroy one unit, then sweep to another unit and destroy it, continually destroying weaker enemy units. However, the attack could only damage one unit at a time. The attack was later changed to a "spray" of beams capable of targeting five units. The attack has more recently changed to resemble the original sweeping animation, but continuing to inflict splash damage.

The colossus used to have an ability to enhanced its shields:


 * Null-Flux Generator
 * Research at: Robotics Support Bay
 * Cost: 200 200
 * This ability enhanced the defensive qualities of a colossus' shield.

This ability was absent from the World Wide Invitational 2008 build.