Flak Jacket

Flak Jacket is a Tier 2 perk featured in Call of Duty: World at War and a Tier 1 perk featured in Call of Duty: Black Ops. It reduces damage to the player by explosives. It is similar to the Perk-a-Cola PhD Flopper in the Nazi Zombies game mode, as they both reduce explosive damage.

Call of Duty: World at War
In Call of Duty: World at War, it is unlocked at rank one in the "Heavy Gunner" class.

Flak Jacket decreases all explosive damage taken by 25%, and caps the maximum damage taken from any one explosive (excluding a direct hit from a grenade launcher, Bazooka or a tank shell) to 75. In effect, this allows the player to survive any single indirect explosive attack. Players who find themselves constantly killed by Grenades, Bouncing Betties, Tanks, Satchels, Artillery Strikes or M9A1 Bazooka will find this perk to be very useful. This perk has very little effect in Hardcore, due to decreasing HP of players, since the 75 damage cap is far above the maximum health level. Getting stuck with a Sticky Grenade with the Flak Jacket equipped will still always result in a death.

Call of Duty: Black Ops
Flak Jacket returns as a Tier 1 perk in Call of Duty: Black Ops.

Overview
Flak Jacket reduces all incoming explosive damage to 35% of its original value (9% in hardcore game modes). Flak Jacket Pro reduces all fire damage to 5% of its original damage, making the Flamethrower and Napalm Strike nearly useless against the player. As an added effect, any thrown grenade picked up by the player will have its fuse reset to 2.5 seconds, allowing safe grenade returns and therefore fulfilling the same role of Toss Back from Call of Duty: World at War.

General Outfit
When the Flak Jacket is equipped it will give the character model extra heavy armor pads on his body resembling that of a Juggernaut. This will count towards all factions besides colors, faces and small details like a helmet. However, it should be noted that Flak Jacket does not make a player a larger target or any slower.

Pro Challenges

 * Protected – Survive 10 explosions while using Flak Jacket.
 * Demolished – Plant or defuse 10 bombs in Demolition, Sabotage, or Search & Destroy.
 * Throwbacks – Throw back 5 enemy frag grenades.

Trivia

 * The Pro effect of Flak Jacket in Call of Duty: Black Ops is the same as the effects of the Call of Duty: World at War perks Toss Back and Fireproof.
 * The Demolished portion of the Flak Jacket Pro challenge is not featured in Combat Training due to there only being Team Deathmatch and Free-For-All gametypes.
 * The throwback challenge cannot be obtained by throwing one's own grenades on the ground, and then throwing them to a safe distance away. However, it can be obtained by picking up an enemy frag just as it is blowing up, even if the player would not have the time to throw it away, thus dying from the explosion.
 * If the player with Flak Jacket is near a teammate that got stuck by a Semtex or a explosive tip arrow and it blows up, the player will still die even though they have Flak Jacket on.
 * The Arctic Spetsnaz model with Flak Jacket is wearing spiked shoes. It is the only model to have this feature.
 * All Flak Jacket models have a patch of the flag of their country on their left arm.
 * The Flak Jacket perk also reduces damage done by the Chopper Gunner and Gunship as they count as explosive rounds. This only appears if there is no direct impact.
 * The Flak Jacket perk for Arctic Spetsnaz shares the same face model as the Spetsnaz Operative.
 * The model in the perks picture is an Op 40 with Flak Jacket.
 * The player cannot get the "Protected" challenge by surviving their own explosions.
 * The Arctic Black Ops and Spetnaz Flak Jacket model was originally going to wear a balaclava, but it was cut in the final version.