V.A.T.S.

One per a combat encounter may enter V.A.T.S. for a short moment. While in this state every attack you make adds triple their associated main skill rather than double and double your luck. Individual body parts of enemies or their weapons may be targeted along with multiple enemies. And you also add your perception to any rolls to resist damage as time seems to slow down while this is active. The amount of shots you can get depends on the weapon you use with the more powerful ones meaning you get less shots in V.A.T.S. Targets you can hit depend on your line of sight, the accuracy of which is affected by this along with other factors.