Weapon and mod details Known weapon statsĪ combat rifle (base AP cost = 22.5 AP multiplier = 1.25) with reflex sight (AP effect = -3):Ģ2.5 + (1.25 x -3) = 18.75 AP cost per shot 10mm Receiver Mods AP Cost Multiple Step Values For instance, the reflex sight has a consistent -3 effect on all gun types tested, but the long barrel mod has an effect of +1 on 10mm pistols, but +4 on hunting rifles. There are some general patterns to how strongly the mods affect all gun types, but it's inconsistent. Combat shotguns, for instance, have an AP multiplier of 1.75, while laser guns have an AP multiplier of 1.25, meaning mods applied to combat shotguns will have a greater impact on AP (up or down) than mods on laser guns.įinally, each mod has an AP effect, which is how strongly it changes the weapon's AP cost. For instance, a 10mm bare receiver costs 21 AP per shot in V.A.T.S., so its AP base value is 21.Įach type of weapon also has an AP multiplier that determines how much effect mods have on the AP of that type of weapon. Weapon base AP cost + (weapon AP multiplier x mod AP effect)Įach weapon has a different base value of action points that it uses per shot. There are three numbers that determine what the AP cost is for every type of modded weapon: the weapon's base AP cost, the weapon's AP multiplier, and the mod's AP effect, and they do it based on this formula: This section is based on research presented in YouTuber RedMage's video: "Fallout 4: VATS and AP Formula Solved!" 10mm pistol The formulaĪttacking from V.A.T.S. This allows for almost any ranged firearm to be customized to fit the player's character build. Grip mods create pistol weapons, while stock mods create rifle weapons.