Extractor
The Extractor is the Zerg building from which Drones collect Vespene Gas. The Extractor is the Zerg equivalent to the Terran Refinery and the Protoss Assimilator.
Competitive Usage
Besides being the fundamental Zerg building for collecting the Vespene Gas resource, the Extractor is sometimes used early game to bypass the 14 food limit by using the Extractor Trick. Players can build one or two Extractors at their main base, start the production of one or two Drones and then cancel the Extractor(s) as a way of avoiding the delay of a morphing Overlord when supply capped. This temporary decrease of supply is only possible for Zerg due to the fact that a morphing Extractor, along with all other Zerg buildings, requires the sacrifice of one Drone. Note that performing this supply trick will only refund 19 of the 25 minerals (75% rounded) used to morph the Extractor.
Scouting or expanding drones that are under siege can be morphed into extractors on the fly to prevent the drone from being killed. They can later be canceled to continue scouting or expanding once the threats have been nullified.
Other
The Extractor is one of only three drone-made Zerg buildings that will not spawn any Broodlings when destroyed (the other two are Spine Crawlers and Spore Crawlers).
ZERG – THE SPAWN OF THE SWARM
WILD. FATIGUE. FLEXIBLE.
Once artificially created by the mighty Xel`Naga, the Zerg would eventually lead to their demise and become a threat to the entire galaxy. Because of their collective consciousness, this species is often referred to simply as “the Swarm.” In their quest for perfection, the Zerg adopt advantageous and superior gene strands into their own gene pool, wiping out “inferior” species in the process.
Zerg Buildings
While the Protoss rely on technological superiority and the Terrans on their adaptability, the savage Zerg rely mostly on pure mass. The mostly lightly armored creatures usually pounce on their opponents from all sides on the battlefield, leaving only a picture of devastation in their wake.
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