Download the Liquipedia app here!Download the Liquipedia app to follow Brood War!Want personalized updates on Brood War esports? Download the Liquipedia app on iOS or Android to never miss your favorite tournaments and matches!
Liquipedia app match pages updated! Liquipedia app match pages are overhauled! Download on Android or iOS! Liquipedia app's match pages got completely revamped with game data, standings, VODs and more! Download the the latest version on iOS or Android and read our update blog here.


From Liquipedia StarCraft Brood War Wiki
Spell Information
Area of Effect:
Target Only
(32 px radius around target hitbox, bigger targets = bigger effect)
Researched from:
Research Cost:
Minerals 200 Vespene Gas 200 Build Time 50.4
Research Hotkey:

Irradiate is an offensive spell cast by the Terran Science Vessel and surrounds the targeted unit with an aura of radioactive energy. It can be cast on any unit (unless in Stasis) and deals 249.9 damage over 25.2 seconds to all biological units within 32 pixels[1] of the affected unit's collision box. [2]

The rate at which it damage is 3.33 damage every 8 frames (23.81 FPS on Fastest), this means that each Irradiate does around 9.92 damage per second for each cast. While multiple casts on the same unit will not stack, the splash damage from multiple Irradiates will stack if the irradiated units are close enough. [3]


Unlike many other Splash Damage type attacks the damage does not decrease with distance. Every unit in the designated range will suffer the full damage unless moved away. This makes Irradiate the most effective splash attack.


In competitive play, Irradiate is often used to snipe high-priority units like Defilers because of the spell's long range and lethality. Alternatively, the splash damage feature is used to damage clumped units like stacked Mutalisks effectively.


Irradiate is virtually never used in this match up as the presence of biological units is severely limited. Even though, in theory, the Eraser will work against SCVs, the high gas cost of the Science Vessel loses to the much needed, gas heavy, Siege Tanks, Goliaths and Dropships. Even when Vessels are in play to counter Battlecruiser Yamato attacks, energy is saved for the EMP spell rather than Irradiate.


Even though Protoss has a priority kill in the High Templar it is often more easily killed off by Vultures. Also, when Vessels are in play, energy is used for the preferred spell EMP Shockwave to counter Arbiters and sometimes High Templar, or removing Protoss shields.


Irradiate flourishes in the vZ match-up as all Zerg units are affected. It is used to counter Mutalisks, which suffer a tremendous amount of damage when a large number of them are stacked together. When Defilers make their appearance on the battlefield, they become high priority targets to Irradiate and Terrans often scan ahead to do an Irradiate raid on these casters. Other victims are Lurkers and Ultralisks. Terrans should always and constantly use Irradiate against Zergs as much as possible if they have Science Vessels.

In rare occasions, a Tank can be Irradiated to damage and kill Zerglings attacking it.


The Eraser is a technique vs. Zerg where Terran targets one of his own mechanical units with Irradiate and uses its splash damage to hurt enemy units, especially Drones. Also, the Eraser is often used to damage Ultraling as they clash with the Terran Ball.


If an Irradiated unit is picked up by a Dropship, Shuttle, or Overlord it will still take damage as well as damaging any biological units that are also in the transporter. The transporter itself however, in the case of an Overlord will not be damaged. If a transporter is Irradiated, any biological units it might be carrying will not receive damage. Of course, should the transporter die, the units in it will die as well.

In Combination with Other Spells[edit]

  • Stasised units cannot be Irradiated. Irradiated units that are stasised will stop receiving damage and Irradiate will wear off after the remainder of the 30 seconds. However, splash damage will still be active.
  • Irradiate will dispel all Hallucinations only if directly cast on the Hallucination. Hallucinations of organic units will suffer splash damage from Irradiate.
  • Irradiate damage will stack with damage from Psionic Storm and Plague, but casting irradiate more than once on any single unit will not stack its damage. Irradiate splash damage, such as having two irradiated units in close proximity, will stack.
  • Irradiate will damage units in Maelstrom or Lockdown.
  • Irradiate can be cured with Restoration.
  • Defensive Matrix will slow down damage dealt by Irradiate, reducing the total amount of damage to 37. If a Protoss unit is D-Matrixed, this damage will be dealt directly to the HP rather than to the shields first.


  • A single Science Vessel cannot cast Irradiate on itself. However, a pair can cast it onto each other.
  • Irradiate deals both air-to-ground and ground-to-air splash damage.
  • Irradiate deals damage and splash damage to own and allied units.
  • Irradiate deals no splash damage to burrowed units. Burrowed units will take damage if they are the target of Irradiat, but the damage won't splash to units around them.
  • Irradiate deals no damage to Larva
  • Irradiate will carry over to both types of Archon if one of the Templars was Irradiated.
  • Drones and Hydralisks can be saved from Irradiate by morphing into a building or Lurker. A Mutalisk, however, cannot be saved by morphing to Guardian or Devourer
  • Drones and SCV that are Irradiated do not suffer any damage while inside a Extractor/Refinery

Notable Games[edit]


  1. Peter Kis (Sonko) (2019-10-27). "Brood War API – The Comprehensive Guide: Movement modifiers, and Terran units".
  2. adapted from: Terran Special Abilities <>
  3. adapted from: Irradiate - Staredit Network Wiki <>