VATS

The Vault-Tec Assisted Targeting System, or V.A.T.S. is the real time with pause combat system in Fallout 3, inspired partly by the ability to target specific body parts in the turn-based combat system of Fallout and Fallout 2. While using V.A.T.S., the otherwise real-time combat is paused. Various actions cost action points, and both the player and enemies can target specific body areas for attacks, inflicting specific injuries.

When using V.A.T.S. against a humanoid enemy, there is generally seven different points you can target; the head, torso, left arm, right arm, currently held weapon, left leg and right leg. However, there may be other points available when facing off non-humanoid creatures. When targeting a part, the screen shows a percentage of how likely the attack will hit the targeted area. Unlike previous Fallout games, it is not possible to target the eyes or groin nor target any individual body parts in melee and unarmed combat (In the case of Melee and Unarmed, the VATS only targets the enemy's head).

As seen from the demo at e3 2008 and PAX 2008, the player character first learns to use V.A.T.S. on his 10th birthday in the vault when he receives a BB gun.