Every character has a maximum of 100 Action Points, regardless of Agility or any other stat or perk. Obviously the AP costs of all actions reflect this change compared to other Fallout games. For example, a rocket launcher costs 90 Action Points to fire.
- 10 AP/s is regenerated when you stand still and don't shoot or perform any other action.
Extra AP Regen
On top of the normal AP Regen, there's an Extra Regen that applies all the time - except for a short moment after you fired a shot (except from certain pistols) and when you are disoriented.
- The Extra AP regen works even while running. The amount of Extra AP regen that you have depends on your Agility. The formula is
3.0 + (0.75 * Agility)
On AoP, you may reload a weapon at any time, even if you don't have enough Action Points. Doing so will bring you to "negative" Action Points, and you will be unable to move or do anything else until your Action Points have regenerated to a positive number. Indeed, some weapons have such humongous reload costs that you will always go to negative AP when you reload them. An example would be the minigun which costs 250 AP to reload.