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Reactor (Legacy of the Void)

From Liquipedia StarCraft 2 Wiki
This article covers the current multiplayer version of this add-on building. For another version see Reactor (Wings of Liberty and Heart of the Swarm).
[e][h]Terran Reactor
Building Information
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The Reactor is one of the two Terran add-on buildings, which can be built from and attached to Barracks, Factories and Starports. It enables the attached building to build two units simultaneously and increases the size of its build queue from 5 to 8.

Because a building can only have one add-on attached to it at a time, the effect of Reactors is restricted to units not requiring Tech Labs:

Competitive Usage[edit]

As Reactors are usually cheaper than building a second production facility of the same kind, they are widely used when building several units of any of the types listed above. Chances are that any building not used for building Tech Lab units ends up with a Reactor sooner or later.

Exchanging the building attached to a Reactor using lift off is a frequent occurrence. For one, it is useful for tech switching. Further, less important production buildings, such as perhaps a Factory in a bio-heavy build, can accelerate unit production by building add-ons for the more important buildings. In particular in the early game, many builds aim for the mass production of certain Factory or Starport units as soon as possible.

Bio openings typically want two Medivacs as soon as possible, but don't require early Factory units, so the Factory is used to build a Reactor while the Starport is built.
TvZ Hellion openings use the Barracks to the build a Reactor for the Factory, such that a lot of Hellions can be made early while the Zerg is likely to mainly have Zerglings for defense, which perform poorly against Hellions.


  • The two units being built simultaneously using a Reactor are independent and do not need to be of the same kind nor start or finish at the same time.
  • When a Reactor is destroyed while multiple units are building ...
    • The construction of the first unit in the queue will proceed regularly, but the second unit will cease making progress. However, its progress is not lost. For example, if a Barracks is just about to complete two Marines before its Reactor is destroyed, the second Marine will still finish moments after the first one.
    • If there are more than 5 units in the queue, it will be automatically shortened to 5 units, returning the resources for the 6th, 7th and 8th unit in the queue.

Patch Changes[edit]

No patch changes so far in LotV.