From Liquipedia Starcraft 2 Wiki
|Description||Battle strider with a powerful area attack. Can step up or down cliffs. Can be targeted by anti-air weapons.|
|Built From||Robotics Facility|
|Cost||300 200 75 6|
|Attributes||Armored, Massive, Mechanical|
|Defense||200 150 1 (+1)|
The Colossus (plural -lossi, -lossuses) is a massive Protoss battle strider that towers over all other ground units on the battlefield. It is built at the Robotics Facility after a Robotics Bay is constructed. Its dual Thermal Lance weapons target units in an area of effect, making the Colossus a powerful siege unit that can quickly destroy an enemy's ground forces. Colossi also have the ability to traverse cliffs and provide vision of high ground areas. However, the Colossus' enormous height also allows anti-air attacks to hit them; care must be taken with Colossi to make sure units like Vikings or Corruptors do not pick them off in battle. The Extended Thermal Lance upgrade gives the Colossus an impressive attack range of 9, which allows them to attack while standing behind their support army.
 Competitive Usage
The Colossus is best considered a heavy support unit, dealing excellent damage with average endurance. On the ground it is virtually unmatched, dealing very high damage to all unit types. A sufficient number of Colossi can destroy ground armies consisting heavily of lower tiered units in seconds. The Thermal Lance upgrade is considered standard for all match ups, as extra range gives the edge against all ground units except deployed Siege Tanks and allows Colossi to fire a safe distance from most ground armies. Take advantage of the Colossus' long range to kite units, and its cliff walking ability to abuse terrain. Most mobile units cannot pursue fleeing Colossi without taking high damage, and Colossi can often make escapes utilizing high terrain.
The primary weakness of the Colossus is its vulnerability to anti-air attacks. Vikings, Corruptors, and Void Rays all receive bonus damage against the Colossus and can easily flank the Protoss army to negate any positional advantage. Hence, a Colossus-heavy Protoss must insure that he has sufficient anti-air to take out the aerial threats of the Colossus.
Unlike its spiritual predecessor, the Reaver, Colossus are mostly ineffective as harassment units. Despite their range, the Colossus is not very effective against structures, as its direct damage is relatively low. And although they deal high damage to workers, workers do not normally line up in a manner that would allow multiple hits. The slow speed of Colossus makes a Warp Prism almost required for the preservation of a singular Colossus, and the high cost and production time makes the limited harassment potential a significant investment.
The Colossus has good synergy with Sentries and Stalkers. Force field can block units, creating lines to keep melee units and such with inferior range away (or trap them) and maximize the Colossus' splash damage, while Stalkers provide the anti-air support and damage absorption that Colossus require. The Colossus can also see up cliffs, allowing Stalkers to Blink across terrain with ease. As a general rule of thumb, if a Robotics is not Chrono Boosted, it is possible to sustain continuous Colossus production with 2 Robotics Facilities per mining base.
 Vs. Protoss
In PvP Colossi are typical in any mid-game ground army; they are fragile if caught alone, but are able to provide critical support fire from long range as part of a strong army. Although Immortals can kill Colossi very quickly, the range upgrade enables Colossus to out-micro and considerably out-range Immortals, which can prevent Immortals from engaging before they are picked off. The Protoss ground army lacks a strong counter to a Colossi without utilizing some Colossi of their own, though Stalkers with Blink and air units can be effective in some situations.
 Vs. Terran
Colossus use against Terran is pivotal to the match-up. After the first Immortal, Protoss users tend to produce Colossi continually from one Robotics for the remainder of the game. Without the use of Colossi or Psionic Storm, Marine/Marauder/Medivac armies are nearly impossible to stop. However, with the aid of Colossi they become vastly easier to deal with. When using Colossi against Terran, you must prepare for a Viking counter, generally by having a sufficient number of Stalkers to shoot down the Vikings before they can significantly damage your Colossus force.
Colossi are also less vulnerable to the Ghost's EMP Round than Immortals or High Templar, as they neither depend on energy for damage nor rely on their shields to protect themselves. Hence, Colossi are generally used as the core unit of a Protoss Army when dealing with a large Terran ground force.
 Vs. Zerg
Against a Zerg, Colossi are incredibly effective in battle if the opposing player decides to make Hydralisk, Zergling or Baneling heavy armies. While not as cost effective against Roaches as their heavy-fire counterpart, the Immortal, smaller amounts of Colossus are still capable of dealing with moderate amounts of Roaches with Sentry and Stalker support, while critical numbers of Colossus can kill larger masses of Roaches very swiftly. Furthermore, Colossi are less effective than Immortals when dealing with Ultralisks in late game, but are still quite capable as support fire to protect units from masses of lower-tiered units. Use of Colossi in PvZ depends on how the Zerg plays; massing Colossi against Muta/Ling play is inefficient (though still relatively effective), but against Hydralisk/Roach heavy Zerg, they are almost essential. In combination with Force Field, Colossi with the range upgrade can safely outrange Hydralisks and Roaches that are blocked by the Forcefield wall. Like when playing Terran, you must be prepared to deal with Corruptors when playing against a Zerg.
- Colossus's sounds (video and sound) - YouTube video.
 Patch Changes
|Patch 1 (version 0.3.0.14093)|
|Patch 6 (version 0.8.0.14593)|
|Patch 11 (version 0.13.0.15250)|