The overlord may evolve into the overseer which is a detector and spellcaster. Overlords are commonly used in the early game to scout areas and gain information on what strategies the opponent is going and what route they attack from. Overlord positioning is key to playing zerg, however picking off overlords can supply block the zerg player. They can commonly be hunted down by cheaper air units such as mutalisks, phoenixes and vikings, as well as roving packs of terran infantry.
Game Unit[]
Versus[]
In Legacy of the Void, the overlord loses its ventral sacs upgrade. Instead, each overlord is upgraded individually to be able to transport units. This upgrade requires a lair.
Upgrades and Abilities[]
Pneumatized Carapace
Increase speed of the overlord from 0.902 to 2.63, overlords with Ventral Sacs from 1.099 to 2.83, and the overseer 2.62 to 4.73.
When Kerrigan reaches a certain level her overlords can be upgraded through one of her abilities to provide more control and be spawned instantly. This ability is called Improved Overlords. Overlords in the campaign lack the ability to transport units.
Upgrades and Abilities[]
Improved Overlords
Overlords morph instantly and provide 50% more control.
All zerg commanders (except Dehaka) use overlords for control and creep generation. All commanders can upgrade overlords with pneumatized carapace and morph to a overseer. Sarah Kerrigan, Zagara and Abathur overlords can be upgrade to transport function. Zagara's overlords use the Leviathan Brood's skin.
The following section contains information from a previous version of StarCraft II which is no longer valid.
The reason for the changes and the split between the overlord and overseer in terms of detection was that the zerg "were somewhat 'detectorific'" in StarCraft.[2]
Overlords briefly lost the ability to transport units in early 2008 but regained the ability by December.[3]
Overlords used to have the Slime and Create Creep abilities.[4] They did not cost energy.[5]
Slime (also known as "Corrupt Minerals")
The overlord could drop a non-attacking slime creature,[5] temporarily disabling resource nodes and xel'naga towers.[6][7] The minerals can be covered as they're being harvested, enabling raids which slow down an enemy's economy.[5] The creature must be killed before the minerals can be accessed.[5][2]
This ability took some time to "cast" and had a small cooldown timer.[5]
Create Creep
Generates a temporary patch of creep on the ground.[5]
StarCraft II beta patch 14 increased the cost of Pneumatized Carapace from 50 minerals and gas to 100. The Patch 1.4.3 Balance Update increased the overlord's movement speed by 25%, from 0.4687 to 0.586.
Before Legacy of the Void, all overlords were upgraded to transports with the Ventral Sacs upgrade. The expansion changed the upgrade to effect individual overlords. As of the Patch 4.2.1 Balance Update, Mutate Ventral Sacs requires a lair instead of an evolution chamber.
Patch 4.0 increased the overlord's movement speed without Pneumatized Carapace from 0.82 to .902. The Patch 4.0.2 Balance Update allowed the overlord to respond more quickly to morph commands. Patch 4.7.1 increased the time between Generate Creep growth periods from 0.36 to 0.45. The Patch 4.10.1 Balance Update decreased the cost of Pneumatized Carapace from 100 minerals and gas to 75 while Patch 4.11 reverted this.
↑ 5.05.15.25.35.45.51) The tier 1 Overlord is very slow and does not have detection, though still essential for scouting throughout the game.
2) They are two different abilities. In generating creep, the Overlord essentially unloads a bunch of creep straight to the ground below it, which expands. Corrupting minerals takes some time to fully cast, but it creates a non-attacking creature that takes over that resource, and needs to be killed before those minerals are able to be gathered. Furthermore, you can corrupt resources that are already being mined, introducing potential Overseer raids to slow the enemy's production.
3)Neither abilities require energy. Creep generation does not have a cooldown whereas corrupt minerals has a small cooldown timer. Karune. 2008-04-25. Overseers having Creep Drop, details?. Battle.net StarCraft II General Discussion Forum. Accessed 2008-04-25.