Action points

Action points (or AP) is a game mechanic governing the number of things a player can do during one combat turn in Fallout and Fallout 2. In Fallout 3, Fallout: New Vegas, and Fallout 4, Action Points are used to fire weapons in the V.A.T.S. mode.

Fallout, Fallout 2 and Fallout Tactics
Action Points are spent firing a weapon, reloading a weapon, fetching equipment from the characters backpack or moving to a new battlefield hex.
 * $$\text{Initial level}=5+\left\lfloor\frac{\text{Agility}}{2}\right\rfloor$$

Example: A starting Agility of 5.
 * $$5+\left\lfloor\frac{5}{2}\right\rfloor=7~\text{Action points}$$

Fallout 3
Action points are consumed in V.A.T.S. system to fire at opponents, each weapon has it own cost per use and can be found in the weapons page. Unlike in the turn-based games, action points in Fallout 3 and Fallout: New Vegas are not accumulated at the end of a turn. Instead, action points are regenerated over time.
 * $$\text{Initial level}=65+(2\times\text{Agility})$$

Example: A starting Agility of 5.
 * $$65+(2\times5)=75~\text{Action points}$$

Fallout 3 AP Bonuses

 * ¹ Due to a coupled penalty of -1 Agility point, the overall effect of the armor is only an increase of 13 AP. This can be offset by wearing Poplar's hood(+1 Agility), or consuming Fire ant nectar(+4 Agility), Alien biogel or Adapted biogel(both biogels have a 5% chance of +2 Agility and a 25% chance of random negative penalty).

Regeneration Rate
Action points are regenerated at a flat rate of 1 per .25 seconds, or 4 per second. A character with average (5) Agility will need 18.75 seconds to fill their AP bar after depleting it.

Fallout: New Vegas
Action Points in New Vegas function mechanically identical to those in Fallout 3, however the agility bonus is now multiplied by 3 instead of 2.
 * $$\text{Initial level}=65+(3\times\text{Agility})$$

Example: A starting Agility of 5.
 * $$65+(3\times5)=80~\text{Action points}$$

Notes:
 * Maximum initial base is capped at 95 AP.
 * This limit can be increased with the addition of bonuses (see table below).

Regeneration Rate
A character will take 16.66 seconds to recover their AP bar to full regardless of their AP total unless their AP is modified by perks. It should be noted that AP gained through perks do NOT count towards regeneration rate. Therefore a player with 115 AP, 30 of which were gained through Action Boy perks, would actually take over 23 seconds to fully recover their AP bar. Furthermore, the perk Nerves of Steel decreases this regeneration period by 20%, to a potential minimum recovery period of 13.33 seconds.

The exact recovery time can be derived from the GECK variable fActionPointsRestoreRate, which in Fallout New Vegas is the inverse of the number of seconds required to fully restore the AP bar. The default value is 0.06 (1/0.06 =16.66 seconds).

Fallout 4
In Fallout 4, action Points function similarly to Fallout 3 and Fallout: New Vegas; however, Agility is multiplied by 10 instead of 2 or 3 to calculate total AP.


 * $$\text{Initial level}=60+(10\times\text{Agility})$$

Example: Starting base Agility of 5.


 * $$60+(10\times5)=110\text{ Action points}$$

Base action points regeneration rate is 6.0% per second or 16.66 seconds (100/6.0) from 0% to 100%.

Action Points are also used when sprinting. The rate at which action points deplete in sprint relies on Endurance.

Fallout 76
Action Points in Fallout 76 function near exactly the same as in Fallout 4; starting at 60 AP and increasing by 10 for every level in Agility.


 * $$60+(10\times\text{Agility})$$

Base action point regeneration rate is 6.0 per second or 16.66 seconds (100/6.0) from 0 to 100%.

Action points are also be used to jump and sprint. The rate at which they deplete while jumping or in sprint relies on Endurance, the Agility perk card Marathoner and being overencumbered. Action points are also spent when attempting to enter VATS while no VATS targets are visible. The cost of this is 5 action points per attempt. No action points are spent when successfully targeting.

Hunger and Thirst also directly affect the number of action points a player has, as well as the regeneration rate. So staying full and hydrated is recommended to be in top shape.