EMP

The EMP (ElectroMagnetic Pulse) is an unlockable killstreak reward in Call of Duty: Modern Warfare 2. Requiring a killstreak of 15, the EMP disables all enemy electronics. Hostile players will have no HUD, and electronic scopes (such as the Red Dot Sight) will be disabled. Their vision will also be slightly fuzzy. Any enemy sentry guns will be destroyed and all hostile aircraft will crash. Enemy players will be unable to activate their own killstreaks while they are affected by an EMP. The EMP effects last for 60 seconds, but does not affect friendlies.

An EMP is featured in the single-player missions Contingency and Second Sun, halting the Russian advance in the Russo-American War.

Weapon Attachments

 * Red Dot Sight - "Red dot" disappears (exceptions - the F2000)
 * Holographic Sight - Targeting reticle disappears.
 * ACOG Scope - Red cross hairs disappear, but the black cross hairs remain.
 * Thermal Scope - Thermal vision is disabled, but crosshairs remain, essentially becomes a standard sniper scope.
 * Heartbeat Sensor - Inoperative, static fills the screen.

Weapons

 * Stinger - Unable to lock on to targets. (Unable to fire.)
 * Javelin - Unable to lock onto enemies or vehicles. (Unable to fire.)
 * AT4 - Unable to lock on to enemy vehicles, though still able to fire in free aim.

Killstreaks

 * All killstreak rewards will be destroyed if they are active at that moment, but the Emergency Airdrop cargo plane will be unaffected and still proceed to drop its load.
 * No killstreak rewards can be activated during the duration in which the EMP is active.
 * The Tactical Nuke is a unique case. While EMP is active, the nuke cannot be activated. However, if the nuke has already been launched, the EMP will not disable it, and the countdown will continue until endgame, presumably because the nuke has already been launched, so nothing much can stop it.

Equipment

 * Claymore - Will not detonate if tripped, but the trip lasers remain active.
 * C4 - Remote detonator is disabled, but can be shot to explode.
 * Throwing Knife - Will fall to the ground.

HUD

 * Everything on the HUD will be gone, and will also show a static overlay on the screen. The only thing that will still appear is the kill broadcaster (bottom left), callsigns and the experience points that pop up once you kill an enemy.
 * The team that uses the EMP will momentarily be blinded by the initial blast of the EMP, as if they were hit by a flashbang, but only for about 2 seconds and their HUD will not be affected by the natural effects of the EMP.

Trivia

 * An EMP should realistically not have any effect on ACOG scopes. This is because they are illuminated by tritium, a radioactive isotope of hydrogen, and contain no electronics like the other optics in the game.
 * An EMP does not affect the digital wrist watches worn by some of the forces like the Rangers.
 * If the player looks outside the map immediately after an EMP is deployed (by either team), they can see a nuclear explosion identical to the one seen in Second Sun in the distant sky.
 * It is odd that setting off an EMP does not affect Semtex grenades as they are detonated electronically.
 * In reality, an EMP blast would not disable electronic devices that are insensitive to excess voltage.
 * The handguns' sights will not have the 3 dots on them once an EMP is detonated; this is not accurate as the dots are painted or tritium-illuminated.
 * Strangely enough, the EMP sometimes affects the televisions in Terminal, but not all the time.
 * The EMP in Modern Warfare 2 is classified as the E1 component of an EMP, as the E2 component is more lightning-like, and the E3 component has a much slower pulse.
 * The EMP is the highest killstreak available in a Care Package. However, the EMP is unobtainable from the Emergency Airdrop
 * The title obtained when completing "Blackout: II" is called "Starfish Prime," which was a high-altitude nuclear test that caused a resulting EMP to affect most of Hawaii.
 * Using two EMPs will complete the Blackout I challenge, unlocking the callsign "Chick Magnet."
 * It is strange that the Throwing Knife is affected by an EMP, since it isn't an electronic device. Meanwhile, the knife used to melee still works.
 * If an AC-130 is being used by a player at the time of the EMP detonation, the player is forced to stop controlling the plane and will come back to their body. The AC-130, however, will remain above.
 * This is one of the 3 killstreaks that cannot be used to kill enemy players. The others are the UAV and Counter-UAV.
 * A friendly EMP used in conjunction with a Chopper Gunner or AC-130 is a deadly combination, as enemies won't be able to use lock-on missiles to shoot down the gunships. A good strategy for obtaining a Tactical Nuke is to try and get 4 more kills and call in an EMP before using your gunship, as you only need 10 more kills once you've got the EMP, and your gunship is unlikely to get shot down.
 * An EMP can be used as a good anti-air support killstreak instead of a launcher. This will benefit your team further in team games as well.
 * The EMP is probably it's most useful in long objective based team games such as Sabotage, Domination, Demolition and Headquarters where the enemy will use killstreak rewards to support their team and help them obtain the objective. The EMP will cancel their killstreaks out and prevent them from using anymore for a considerable period of time whilst your team can freely use your own killstreaks which is brilliant for your team and can turn the tide of a game. The enemy will find it much harder to defend against your team's killstreaks as lock on missiles will prove ineffective. They will also find it more difficult to spot harriers, helicopters, predator missiles etc because the radar is temporalily disabled.