Perk slot 1:
Lightweight - Allows you to move quicker
Scavenger - Resupply ammo off the dead.
Ghost - Basically like Cold Blooded from MW2, invisible on radar unless you shoot without a silencer.
Flak Jacket - Ability to survive explosives close range.
Perk slot 2:
Hardened - Increased bullet damage
Scout - Increases the time to steady weapons with scopes. Good for snipers.
Steady Aim - Speaks for itself, increases hip fire accuracy.
Sleight of Hand - Cuts the reload time in half. Quick reloads.
Warlord - Gives you the ability to make 2 attachments to primary weapon.
Perk slot 3:
Marathon - Another returning perk, increased speed while sprinting.
Ninja - Gives you stealthy advantage when approaching enemies.
Second Chance - Go on the ground with your pistol after being gunned down. You survive for 10 seconds, or whenever you are hit.
Hacker - Ability to detect enemy explosives and tactical insertions. Highlights them red.
Tactical Mask - Resistant to flash bangs and gases.