Radiated (Fallout 4)

Radiated is a condition in Fallout 4.

Gameplay
Radiation decreases max health as radiation poisoning rises. The rate is 1% of HP per 10 rads, with 1000 the fatal level. In addition, Fallout 4 features radiation damage as a damage type that can appear on weapons.

Radiation poisoning is the more common type; for example, it is the effect on all "irradiated" legendary weapon prefixes and the gamma gun. This functions exactly like environmental radiation in Fallout 4: 10 points of radiation poisoning will reduce max health by 1%. This gets reflected as actual damage, even if a character is at full health. Since this directly affects maximum health, this is damage that can't be healed. Even legendary enemy mutations or the console command will restore health only up to any limits from radiation poisoning.

Resistances
The game distinguishes between the radiation immunity Super Mutants have and the resistance feral ghouls have. Some weapons do pure radiation damage that ignores radiation immunity. These weapons are still affected by radiation resistance, so they will do more damage to an "immune" target than one with high resistance. Groups such as the Children of Atom have weaponized radiation to create traps and even handheld weapons ranging from improvised pistols to automatic rifles and grenades.