Stun Immune is a trait of several alien species in XCOM: Enemy Unknown.

This unit cannot be stunned with the Arc Thrower; taking a live specimen is not possible.

– In-Game Description, XCOM: Enemy Unknown


Stun Immune aliens cannot be captured alive by XCOM troops. Chryssalids, Cyberdiscs, Drones, Sectopods and Zombies all benefit from this trait.

In XCOM: Enemy Within, Mechtoids and Seekers are also Stun Immune.

EXALT operatives can have the Arc Thrower used on them, however, they will kill themselves before they are knocked out, stopping you from getting the captive. The Arc Thrower can still be useful for instantly taking the target out of a fight, however.


  • The Arc Thrower can be upgraded via the Foundry to take control of Drones during missions but this still does not reward a captured Drone at the end of the mission.
  • As these enemies cannot be captured, there are no interrogation rewards associated with them.