Radiation

Radiation is a non-standard damage type used by both Xeno and Narvidians to supplement their physical damage (no Templar uses radiation in their attacks). Currently it is not an environmental hazard on any mission.

Mechanics
Like all non-standard damage types, rolls for dealing radiation damage range between 30% and 100% of the stated damage. This differs from bonus damage from other sources which is from 0% to 100% of the stated damage. This, combined with the fact that non-standard damage types ignore armor, makes it very dangerous to your Templars. (Non-standard attacks do have to contend with opposing Resistance and Res, but those are usually very weak defenses.)

Known Radiation Users
Radiation resistance can be improved by selecting certain Templar Armor and War Gear. No enemy exhibits radiation resistance, but Templars have no way to deal radiation damage anyway.

Radiation damage is a supplementary damage (<40% of total max damage possible), and is dealt by most of the Narvidians excluding the Flamespider, as well as 6 species of Xeno: Radiated Scittering, Radiation Brood, Brood Lancer, Spitter, Lancer and Spined Goltank.