The Guardian is a Zerg Hive-tech flying siege unit. Guardians are morphed from Mutalisks, via the Cocoon, after the required Greater Spire structure has been constructed. Mutalisks can also morph into Devourers.
The Guardian is very slow moving, but its power lies in its long attack range. It out ranges all ground units that can attack it except Goliaths with the range upgrade and Ghosts in Bunkers. The Guardian is unable to attack air units, which in combination with its necessarily slow speed, therefore make it vulnerable to attack from other flying units.
Guardians are quite powerful against units that cannot attack it while it is sieging, for example, a mineral line while it is outside of attacking range, but the Greater Spire and its own cost make it an expensive investment. Guardians are not strong in health or mobility either, as Mutalisks are, so they tend to be reserved to the late-game with a massive economy, much like the Ultralisk.
The Guardian attack and armor, or Carapace, can further be upgraded at the Spire and Greater Spire.
Because Guardians are slow and cumbersome in their movement, they must be monitored during an attack. In particular, when being used over a cliff against defensive ground-to-air structures such as Photon Cannons and Missile Turrets, the Guardian will have a longer range than these structures, but due to their awkward flying motion, they will frequently enter into the offensive range of the structure until the Zerg player commands it to move backwards out of firing range.
There is no real use for Guardians in ZvZ because it is primarily an air to air battle. Further, Hive stage technology is very rare. If the opponent made Hydralisks and Lurkers it might be viable to use Guardians to siege the base, but it is an expensive investment, enough so that opponent can use the opportunity to make air-to-air. The cost and situational use means there are generally other ways to be applied to win from an advantage.
Guardians are effective versus Bio M&M with Mutalisk support, being able to kill Marines very quickly and out-ranging them by a good distance. Guardians are limited in their effectiveness as they veer into an opponent base, however, as they can be killed quickly without the benefit of its range-advantage by Marines with Stim Pack. The Guardian remains very effective until the Terran player has either Science Vessels and Irradiate researched, or a large number of anti-air units such as Wraiths, Goliaths or Valkyries. Guardians are usually seen when a Zerg player has gone for a 2 Hatch build and is playing on a map with an easily protected third Vespene Gas Geyser such as Outsider or Troy. Guardians are sometimes seen with a 3 Hatch.
Some Zerg players like to morph their remaining Mutalisks to Guardians in late-game in order to disrupt the mining of the Terran on the way to transitioning into Defilers and a ground-based army. This variation gets less effective when the Terran players is able to get enough Science Vessels or when Terran relies on a Goliath based army.
Due to their high cost and high tech level, Guardians are not commonly used versus Protoss. However, they can still be effective support and harassment units. Two Guardians can effectively stop mining at an expansion if the Protoss has no Corsairs or is slow to react. Although strong when combined with large numbers of ground units, isolated Guardians over ground can be easily destroyed by Psionic Storm, Dragoons, and Archons. Since the cost of a Guardian is about equivalent to that of a Ultralisk, players will often prefer to opt to produce the Ultralisk because of its greater potential as a tank unit and damage dealer.
- The mineral, gas, supply, and time cost are taking into considering the cost of the Mutalisk used.
- List of Jaedong’s games with Guardians usage.