Care Package

The Care Package is a killstreak reward in Call of Duty: Modern Warfare 2, Call of Duty: Black Ops, Call of Duty: Modern Warfare 3, Call of Duty: Black Ops II and Call of Duty: Black Ops: Declassified, that will drop a random killstreak or ammo. In Call of Duty: Modern Warfare 3 and Call of Duty: Black Ops II, the Care Packages do not give ammo drops.

Description
This crate can contain a either a full ammo restock or a killstreak other than the Emergency Airdrop, Tactical Nuke or another Care Package. This helicopter can be shot down before dropping the care package, although it's relatively difficult to do so, causing the care package to drop instantly.

There were initially two major glitches with airdrop-based killstreak rewards. While holding the Care Package, players would receive a large increase in movement speed, as well as a 25% health boost, which was often combined with Marathon, Lightweight, and Commando for extremely fast knifing classes. The other glitch allowed players to have infinite Care Packages to continuously call in whichever Care Package based killstreak reward they had. A patch to fix the problems was finally released on PC and PS3 on January 29, and on Xbox 360 on February 12.

Content Probabilities
The probability of any given item is as follows:

Call of Duty: Black Ops
The Care Package returned in Call of Duty: Black Ops. It now requires a 5-killstreak (4 with Hardline) to obtain and is available to the player from the start along with the Spy Plane and Attack Helicopter. Care Packages are delivered by a CH-47 Chinook. The speed of the helicopter delivering the Care Package has been reduced from that of Call of Duty: Modern Warfare 2, and the helicopters can now be destroyed much more easily before the Care Package is delivered. If the helicopter delivering the package is destroyed before it drops the Care Package, the Care Package will be dropped from wherever the helicopter was shot down. 400 XP is awarded shooting down a care package helicopter. The Care Package this time is delivered by a blue smoke grenade instead of red.

As seen in the multiplayer reveal, the Care Package now gives the user high powered weapons in addition to Killstreaks, which could be a Grim Reaper (a launcher) or a Death Machine. Furthermore, with the effect of Hardline Pro, players have a chance to receive another randomized reward, if they are dissatisfied with the initial Care Package. However, the effects are pretty much 50/50: the player could get a worse reward the second time, or alternatively enemy players may have enough time to get to the players location and kill them before the Care Package arrives. Thus the enemy can possibly steal the contents.

As with all other helicopter-based killstreaks in Call of Duty: Black Ops, the CH-47's paint scheme will vary depending on whether it belongs to friendly or hostile forces. Friendly CH-47s are painted in the typical U.S. Military gray scheme, while enemies are painted with gray camouflage and red markings. The crates themselves also differ in appearance. Friendly crates appear green, enemy crates are red, and enemy crates that have been stolen and booby-trapped by a player with Hacker Pro will appear black with red skull and cross-bones markings to that player and any teammates. A useful strategy is to pair it with a Counter-Spy Plane, as it can protect it from the enemies who wish to steal the crate. An additional feature with the Care Package is that one can kill someone either with the flare itself, or with the falling care package, although it is very hard to do so.

Call of Duty: Modern Warfare 3
The Care Package appears in Call of Duty: Modern Warfare 3 as a 4-point Assault pointstreak. It is mostly unchanged from Call of Duty: Black Ops and Call of Duty: Modern Warfare 2, although there are no longer crates that contain ammo. A player cannot receive a Support pointstreak from a Care Package. Only Assault Pointstreaks are obtainable. It takes 10 seconds for the care package to arrive, so the player has to guard the place where they chose the care package to come in at.

It should be noted that Care Packages dropped from the Escort Airdrop are different from their Assault Strike Package counterparts. Escort Airdrop Care Packages will usually contain Support Strike Package pointstreaks, although it is possible for them to contain Assault Strike Package pointstreaks as well. When the helicopter is shot down, the care package will fall down from where it was shot down. Destroying the helicopter rewards 300 xp and one point on to the player's pointstreak.

Special Ops
They also appear in Special Ops. They appear in Special Ops Chaos, Survival Mode, Special Delivery, and Vertigo. The Survival Variant will contain a perk purchased by the player, the one(s) in Vertigo will contain parachutes, the ones in Chaos Mode will contain either a Combo Freeze, a Sentry Gun, a Self Revive, Bonus Points, or Extra Time, and the ones in Special Delivery will contain a Self Revive, a Sentry Gun, or an XM25.

Advantages
The Care Package will release a killstreak for the player's use, similar to any other definite reward, and shooting down the delivery copter will only serve to drop the contents immediately. A falling Care Package will kill any enemy, even if it has the Riot Shield or is using the Juggernaut suit.

Limitations
Because the Care Package essentially contains a 'random' reward, players are basically gambling with their chances, and 'low end' killstreaks are a lot more common than 'high end' items. The very act of throwing an air support marker will alert wary enemies due to the smoke, allowing them to close the distance and eliminate the player with the drop grenade. Players are also vulnerable to being attacked when waiting for a package thus enemies can 'steal' one's reward.

Furthermore, the Care Package can give one 'any' item, so players must use it carefully if the specific reward does not complement the game mode and/ or map. No ammo is replenished, requiring Scavenger if one is running low on bullets. Players from the same team can be killed, with a dropping crate, effectively giving the enemy free points; and the item, when acquired, will not chain kills together for the next reward.

Call of Duty: Black Ops: Declassified
The Care Package appears in Call of Duty: Black Ops: Declassified in both multiplayer and Hostiles.

Call of Duty: Black Ops II
The Care Package returns in Call of Duty: Black Ops II and functions similarly to previous titles but, similar to its Modern Warfare 3 counterpart, will not yield ammunition. The Care Package requires a scorestreak of 550. It can be hacked with the Black Hat PDA by the user - to capture it from a distance, by your own team - to capture it in the same fashion (although slower), or by the opponent - to booby trap it (the scorestreak rerolls, however when opened by the team whose carepackage it originally was it will explode). The kills a player gains from the contents of a  dropped care package do not count towards challenges of those particular scorestreaks (unless the player using the scoresteak has unlocked and equipped that particular scorestreak). When equipped, the Engineer perk allows players to change the care package contents 1 time per care package.

General

 * Friendly care packages in Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3 can kill teammates, while in Call of Duty: Black Ops and Call of Duty: Black Ops II they cannot.
 * If a Care Package falls on a player, it naturally kills said player and grants the kill to the one who placed the package. Thus, it is possible to win a match by killing someone with a falling Care Package.
 * In Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3, the smoke from the Care Package marker is red, while in Call of Duty: Black Ops and Call of Duty: Black Ops II, it is blue.
 * The icon of the Care Package shows it with a parachute, though in-game it does not drop with one.

Call of Duty: Modern Warfare 2

 * The smoke coming from the smoke grenade always goes north.
 * When obtained, the multiplayer announcer will call it a Care Package, but the text alerting the player to the killstreak will say "Airdrop". In game files, sounds for Airdrop killstreak can be found.
 * Prior to a patch, the player's sprint distance was increased when holding a Care Package Marker.
 * If the Care Package falls on a player during a host migration (during which the player is invincible), the player gets stuck in the Care Package until the package is 'opened', as showcased in this video. Said player can, however, collect the Care Package.
 * The radius from which players can open a care package actually forms a sphere, allowing some lucky players to capture a care package from underneath it. This can commonly be done in maps like Favela, where Care Packages can land on roofs or other structures.
 * The red smoke from the smoke grenade used to call in a Care Package does not appear in the Game Winning Killcam.

Call of Duty: Black Ops

 * Test dummies in Combat Training will commonly attempt to take the player's care packages.
 * Test dummies in Combat Training can booby trap Care Packages. If Hardline Pro is obtained, they can even change what is inside the care packages.
 * Up to three Care Packages can be called in at a time if there are no other aircraft present.
 * If two or three Care Packages are called in on the same location, the helicopters will pass right through each other.
 * One can be pushed out of a map by a Care Package in, however, they need to be in a very tight and condense spot.
 * Prior to a patch, players could re-roll Sam Turret crates and Valkyrie Rockets crates with Hardline Pro. This was later patched to Care Package only.
 * If one gets killed near a booby-trapped care package then the Kill-Cam will show the black package, rather than the green package it would normally show.

Call of Duty: Modern Warfare 3

 * In Survival Mode, perk Care Packages are instantly collected. Also, its collecting radius is smaller than in multiplayer. If another player attempts to collect the "perk care package" they will too collect it instantly.
 * If the player is hit by the falling care package in Survival Mode, it will not kill the player, nor deal any damage, unlike in multiplayer.
 * Perk Care Packages in Survival mode have the Task Force 141 logo on them.
 * A Trophy System can destroy a Care Package marker and will not grant the player the desired streak.
 * Unlike previous games, the Care Packages no longer supplies ammo in multiplayer mode.
 * The Special Ops mission Vertigo is the first Spec Ops mission to have Care Packages. Second is Special Delivery.
 * The old icon for the care package states that ammo can be replenished but was cut for unknown reasons.
 * The carepackage grenade has "JU57T1C3" written on it which is similar to "JUSTICE"