The Blast Shield is an equipment item in Call of Duty: Modern Warfare 2. The Blast Shield provides a 0.65x damage reduction against explosives as well as immunity to Stun Grenade, but not Flash Grenades. It is similar to the perk Flak Jacket from Call of Duty: World at War and Call of Duty: Black Ops. Pressing the Use Equipment button toggles the mask on or off. While wearing the Blast Shield, the mini-map is lost and the far edges of a player's screen are blacked out. It is not to be confused with the Riot Shield, which is a Primary Weapon rather than equipment. However, if used in conjunction, the Blast Shield and the Riot Shield can reduce the fatality risk from Semtex and other explosives unless the enemy is using Danger Close, mainly because the two cancel each other out, much like Stopping Power and Juggernaut from Call of Duty 4: Modern Warfare and Call of Duty: World At War.
This equipment is most useful when the player must remain stationary in one place, either while camping an upper floor sniper position or during objective game modes such as Headquarters or Domination when the player is constantly being bombarded with grenades. It is also a useful option while aggressively clearing rooms and areas, this way the player is less likely to be killed from an explosive and cannot fall victim to Stun Grenades. When used with a Riot Shield, a player stuck with a Semtex can equip their Blast Shield and charge at the enemy who threw it, forcing them to suicide. You die when you're stuck with Semtex regardless of blast shield and riot shield combined. Having either Lightweight or Marathon perks in this situation is recommended, as otherwise the target may reach a survivable distance or escape.
The Blast Shield can also be extremely useful while using launchers that do not have a minimum detonation distance, mainly the AT4 and the RPG-7, as this allows the player to use said explosives at shorter ranges without committing suicide. Additionally, in these situations where the player finds it useful to use explosives, the enemy is more likely to be using explosives, thus protecting the player from them as well. With Blast Shield equipped, a shot from the AT4 can land at a player's feet and not kill them, assuming they were not very badly injured prior to the blast.
In Hardcore modes, wearing the Blast Shield constantly is not a problem as the mini-map is off by default unless a UAV is airborne. However, due to the low health in Hardcore modes, its use is questionable, as even reduced explosive weapon damage can kill the user. For example, with RPG and AT-4 rockets (Damage 160-30), the rockets must hit the player at a distance much more than half of the explosion's range for the player to survive, whereas in core, the explosion can occur at a maximum of around 3 feet for the player to survive. In core modes, the mask can very quickly be flipped on when a grenade indicator appears. This technique will not work against Stun grenades, grenade launchers, or rocket launchers which explode instantly, although with quick reflexes the shield can be put on while said projectiles are still in the air.
One task the Blast Shield excels at is protection for the player while defusing a bomb. In Sabotage, Search and Destroy, and Demolition, defuses are often cut short by Frag or Semtex grenades. With the Blast Shield, both types of grenades must be practically on top of a player to kill, giving the defuser a lot of protection against random grenades. Although it is rarely used competitively, the Blast Shield has potential to be useful in competitive matches.
- When a grenade or any other explosive is used against a Blast Shield user when he has it equipped, the regular hit marker plus a mini blast shield icon is shown when he is hit.
- The Blast Shield does not counter the Predator Missile, although the player who used the Predator Missile will still see a Blast Shield hit marker.
- The Blast Shield is a sort of fusion of the Flak Jacket and Gas Mask perks of Call of Duty: World at War, reducing explosive damage and stun grenades' effects (or Tabun Gas in Call of Duty: World at War). However, as an equipment, it is not passive like the two perks; it must be activated.
- The Blast Shield's challenges might be the easiest of all equipment challenges to complete as any sort of explosion will count for the challenge. This includes surviving explosions from flammable barrels and vehicles. One can easily survive up to 10 explosions in one round on a map with numerous flammable barrels such as Highrise or Quarry.
- The user's own explosions can count towards the challenge.
- At full health, a Riot Shield user with a Blast Shield equipped will survive a Semtex stuck on the Riot Shield, unless the thrower is using Danger Close.
- The Blast Shield icon in Create-A-Class will always have a Bronze Digital Camouflage.
- The Blast Shield used to be extremely overpowered as even an RPG-7 couldn't kill an enemy player with one on. But it was patched in an update.