Perks

Perks are used in classes to give players a boost in some way or another. There are three different categories of perks: Perk 1, Perk 2 and Perk 3. If you use wildcards you can equip up to 6 perks. Here are all of the different Black Ops 2 perks:

PERK 1

Lightweight
This perk allows you to run faster and take no fall damage whatsoever.

Flak Jacket
Decreases explosive damage dealt on you, which means that, at full health, no explosives can kill you in 1 hit.

Blind Eye
This means that any Air Support Scorestreaks that aren't player-controlled can't detect you.

Hardline
This perk gives you bonus points for everything you do (e.g. capturing an enemy flag would normally get you 200, with Hardline it gets you 250)

Ghost
Enemy UAVs can't detect you whilst moving. However, if you stand still, you'll show up on the enemy UAV.
Ghost

PERK 2

Hard Wired
Makes you immune to Counter UAVs and EMP Systems. However, even though you are immune to EMPs, you still can't call in Scorestreaks.

Scavenger
For every enemy you kill (excluding with explosives), you will replenish ammo, equipment and grenades. Killed enemies leave behind Scavenger Bags which contain more equipment.

Cold Blooded
Makes you invisible to enemy targeting systems (Sensor Grenade, Dual Band etc.) and enemy air support Scorestreaks can't target you normally.

Fast Hands
Weapons can be switched quicker, you can throw grenades faster and you can throw enemy grenades back at them.

Toughness
This perk reduces your flinch when shot by an enemy.

PERK 3

Dexterity
Makes you climb ladders and jump over walls 50% faster. Also makes you heal faster when you've taken damage and you can aim faster after sprinting.

Engineer
Allows enemy equipment to glow red through walls. This perk also delays enemy explosives that were triggered by you. You can booby-trap Care Packages and re-roll Care Packages in hope of something better.