Scorestreaks allow you to call in power support, ranging from simple UAV reconnaissance to highly destructive gunships and heavily armored robots. You can select up to three Scorestreaks and they won't reduce points from your class build, since they are separated from the Pick 10 system. Earning points in combat rewards you with your selected Scorestreaks.
You earn streak points by taking out other players, but it isn't the only way to earn them. Taking out enemy Killstreaks and completing objectives in different games modes also score you points. In Capture the Flag, for example, you're better rewarded for capturing the enemy flag than engaging enemies.
Your points are reset upon death. You can accelerate your earned score with Seraph's (Specialist) Combat Focus ability.
Remote-controlled Hover-Capable Explosive Device with a charge that can be detonated at any time. The HC-XD can perform a thrust-powered jump and drive on walls.
Unlocked at Rank 9
Unmanned Aerial Vehicle that periodically sweeps the radar and reveals enemy locations as dots. Can be shot down with normal weapons and launchers.
Unlocked at Rank 1
Airdrops a Care Package to the selected location. The package contains a random killstreak.
The Care Package can be hijacked and booby trapped by the enemy if left unattended.
Unlocked at Rank 12
The Counter-UAV jams the enemy radar and gives your team a slight information advantage. Can be shot down with normal weapons and launchers.
Unlocked at Rank 27
Anti-personnel drone equipped with three lock-on missiles. This is player controlled, unlike the AI controlled Hunter Killer killstreak from Black Ops 2.
Once you lock-on to an enemy player or Scorestreak, you can fire a missile that seeks out the target. The Dart can also dive bomb for an explosive blast.
Unlocked at Rank 18
The Guardian deploys a microwave dish that can stagger, stun, disorient, and eventually kill any enemy that comes into range of the microwave beam.
Unlocked at Rank 36
Launches a coordinated airstrike on three targets of your choice. You can do one UAV sweep to make your airstrike more accurate.
Unlocked at Rank 21
Remotely launched precision missile with booster rockets. Comes with a cluster bomb payload that can be deployed to strike a wider area. Hellstorm is ideal for hammering key objectives, like control points in Domination.
Unlocked at Rank 1
Deploys an automated Hardened Sentry that can also be remote-controlled.
Unlocked at Rank 45
Airdropped into the selected location where it will automatically patrol and engage enemies. Can be player controlled at will.
The Cerberus is equipped with a powerful machine gun and rockets.
Unlocked at Rank 30
Deploy a targeted explosive drone bomb strike.
Unlocked at Rank 42
AI or player controlled escort attack drone with a minigun.
Unlocked at Rank 1
Calls in a friendly attack craft with advanced stealth capabilities. The Wraith has a defensive flak drone to ward off incoming missiles.
Unlocked at Rank 39
Gives your team the perfect surveillance of the entire enemy team with their exact locations and the direction they are facing.
The H.A.T.R. isn't orbital, but it can only be shot down by launchers.
Unlocked at Rank 48
Airdrops multiple Robotic Anti-Personnel Sentry drones to the map that assault the enemy team like the K9 Unit killstreak from BO2.
Unlocked at Rank 15
Once the device has been deployed it disables enemy electronics and cripples their thruster-assisted movements. The Power Core can be destroyed.
Unlocked at Rank 33
Heavily armored Juggernaut robot with an LMG. Can be set to patrol mode where it will defend a designated area. You can also set it to guard mode where it will follow and protect you.
Unlocked at Rank 24
Powerful VTOL gunship with one primary and two secondary turrets. Delivers massive destruction with its powerful machine guns and rockets.
Teammates can join in and take control of the secondary turrets, as long as they haven't been destroyed. The Mothership can take a lot of damage before it goes out of commission.
Unlocked at Rank 51