With the Sniper perk, you can hold your breath longer while aiming. Higher ranks add a chance of knockdown with single-shot scoped weapons, and a bonus to headshots in V.A.T.S.”— Fallout 4 loading screen hints
All three ranks of this perk focus on improving long ranged combat with scoped rifles.
- Rank 1: Reduces sway when zoomed in and extends hold breath duration.
- Rank 2: Non-automatic, scoped rifles can knock down enemies.
- Rank 3: Increases head shot accuracy in V.A.T.S. by 25%.