Awareness (Fallout Supplement)
From D&D Wiki
You are more likely to notice details about people. Awareness will give more detailed information about them when you succeed a Spot check.
Prerequisite: Level 6, 4 ranks in Spot
Benefit: You know the HP, Defense, Equipped Weapon, and Ammunition Count of any characters, creatures and robots when you succeed a Spot check(DC=20). For combat purposes only.