Icon disambig
For the perk, see Rad Resistance.
The amount of radiation you are exposed to is reduced by this percentage. Radiation Resistance can be modified by the type of armor worn, and anti-radiation chems.— Fallout In-game description

Radiation Resistance is a derived statistic in Fallout, Fallout 2, Fallout 3, Fallout: New Vegas, Fallout 4, and Fallout Tactics.

It reduces radiation damage by a percentage.

Rad-X temporarily increases Radiation Resistance.

Fallout, Fallout 2, Fallout: New Vegas, Fallout TacticsEdit

$ \text{Initial level}=\text{Endurance}\times2 $

Temporarily increasing Radiation ResistanceEdit

  • Any temporary increase to Endurance.
  • Gametitle-FNV The space suit increases Radiation Resistance by 40% while worn, as will various other items of clothing and armor.
  • Rad-X temporarily increases radiation resistance:
    • In Fallout, Fallout 2, and Fallout Tactics, Rad-X temporarily increases radiation resistance by 50%. Half of it is lost after 24 hours, with resistance returning to its original value after another 24 hours.
    • In Fallout New Vegas, Rad-X increases radiation resistance by $ \left(25 + \frac{Medicine}{2}\right)% $ for 4 minutes per dose taken (the durations add, not the magnitude), up to 75% at 100 Medicine (enough to reach the cap of 85% with only 5 Endurance).

Permanently increasing Radiation ResistanceEdit

  • Any permanent increase to Endurance.
  • The Rad Resistance perk increases radiation resistance by 15% per rank. (25% in New Vegas, where it only has 1 rank)
  • In Fallout 2, the Vault City Inoculations perk increases radiation resistance by 10%.


  • Average characters will have a 10% radiation resistance.
  • The Fast Metabolism trait sets initial radiation resistance to 0.
  • In Fallout, Radiation Resistance can go as high as 100%, which is needed to survive The Glow. In Fallout 2, it is capped at 95%; in Fallout: New Vegas, however, it is capped at 85%.

Fallout 3Edit

$ \text{Initial level }%=(\text{Endurance}-1)\times2 $

Example: A starting Endurance of 5.

$ (5-1)\times2=8\% $

Permanently increasing Radiation ResistanceEdit

Temporarily increasing Radiation ResistanceEdit


  • In Fallout 3, Radiation Resistance is capped at 85%.

Fallout 4Edit

Radiation resistance works similar to the other games, but is more crucial because radiation damage itself is much more dangerous than previous titles, lowering a player character's maximum health by 1 percent for every 10 Rads absorbed. Resistance is not gained from Endurance any longer, but now appears on much more equipment, such as vault jumpsuits and gas masks.

Resistance effects are still present on radiation suits, now called a hazmat suit, as well as all forms of power armor, which can be modified to offer even more protection, wearing either of these essentially renders the wearer immune to background radiation.

One dose of Rad-X is no longer an incredibly potent, easy-to-use form of protection, only offering 100 Rad Resistance. However, multiple doses can be taken, each one stacking for the duration.

Rad Resistance does not work in percentage terms as in earlier games. Power armor can provide over 1,000 rad resist; this helps significantly but still does not make one completely immune to radiation. The basic principle is that if one's rads/second is exactly equal to their Rad Resistance, they will take half damage. If one goes swimming (10 rads/s in water) with a Rad Resistance of 10, they will only take 5 rads/s. Higher or lower resistance relative to the radiation level modifies the percent of damage one takes, but the effects diminish on both sides; even 5 rad resist will significantly mitigate low-level radiation, but rads will still seep through the toughest of power armor.

Because of this, exposure to radiation will be relatively severe if one is unprotected, but most sources of radiation will become less hazardous as one acquires Radiation Resistance.

Permanently increasing Radiation ResistanceEdit

Temporarily increasing Radiation ResistanceEdit

Notable apparelEdit