Aimed Shot

An aimed shot, or targeted shot, allows the shooter to aim at a specific part of a target's body during combat. The accuracy of these shots depends on the targeted area - the torso and limbs are easy to hit, while the eyes and head are harder. Using an aimed shot instead of a regular one increases the chance of a Critical Hit by the exact same amount as the aiming penalty for the targeted area. The bonus effects of aimed shots can only be activated during a critical hit. Aimed shot is selected by right-clicking the weapon display or hitting the N key until a 'crosshair' shows.

With the Fast Shot trait, aimed shots cannot be done.

Use
Usually it is best to target areas with the most associated aiming penalty but still have high to-hit chance (90-95%) - this nets the highest possible critical chance, while not compromising on the accuracy. Different tactical situations may call for different aimed shots:

In a first-strike situation, it is usually best to strike the deadliest blow possible:
 * Eyes &mdash; Has the highest critical hit potential: highest damage multiplier, often ignores armor and can blind, reducing opponent's accuracy
 * Head &mdash; Has a bit less critical hit potential and damage than eye shots: but still often ignores armor and can knock targets out
 * Groin &mdash; Less critical hit potential and damage than head shots: but can sometimes ignore armor and often knock down/out targets

In a defensive situation, it may be worth it to try to disarm or disable the enemy. In such situations the areas to target would be:
 * Arms &mdash; Crippling one arm will prevent an opponent from using a two-handed or heavy weapon. Crippling both will prevent any ability to attack.
 * Legs &mdash; Knockdowns. Crippled legs severely reduce opponent's movement
 * The downside to these areas is that they imply lower critical hit chance than Eyes/Head, therefore earn critical hits less often.

Gallery
Fallout and Fallout 2 have a couple of targeting renders for the Pip-Boy 2000. Fallout Tactics has a slightly different renders because of using a 2000 B.E.