Energy resistance

Energy Resistance is a derived statistic in Fallout: New Vegas and Fallout 76.

Fallout: New Vegas

 * Energy Resistance allows the player to resist energy weapons.
 * Curiously the only items in the entire Fallout universe that modify this are the Atomic cocktail and the Marked beast helmet.

Fallout 76
Damage resistance in both of the Creation Engine games is essentially the same and uses three separate armor types for the three available damage types:


 * DamageResist, used to determine resistance against ballistic or normal weapons - most conventional firearms, melee, and unarmed weapons, as well as creature attacks,
 * EnergyResist, used against weapons dealing energy damage,
 * RadiationResist, used against - what else? - radiation-based weapons.

To determine the damage reduction, the game first checks the following:
 * If target has 0 Armor = 0% DamageReduction
 * If Armor < 15% AttackDamage = 1% Damage Reduction
 * If Armor > 550x Attack Damage = 95% Damage Reduction

Otherwise, it performs the following calculation:


 * DamageReduction = 1-0.5*(AttackDamage / DamageResist)^0.3653

At extreme values, Energy damage can be nullified, but Ballistic or Normal damage will only be reduced by a max of 95%.

Fallout New Vegas

 * The Plasma Defender (as well as the Gun Runners' version and Arcade Gannon's personal one), recharger pistol (and the unique MF Hyperbreeder Alpha), laser RCW, all types of laser automated turrets, all eyebot zappers, and Dead Money ' s holorifle ignore energy resistance. In addition, the incendiary grenade, Dead Money ' s gas bomb, and Honest Hearts ' s fire bomb are affected by energy resistance, where they should be affected by fire resistance.