Treyarch is looking to mix things even further than what Infinity Ward did with Modern Warfare with its new Score Streaks system. Players will earn points towards the "Score Streak Meter" for kills and "Scoring Events", such as capturing a flag or enemy location. Once that meter fills up your score streak will be active, giving you access to one of the 22 score streaks available in the game. You'll need to play rather skillfully and strategically to unlock all 22.
The difference from Modern Warfare 3's pointstreak system is that it's possible to unlock two score streaks at once: for example, you might manage to grab a flag, kill an enemy and eventually capture the flag, which would give you 400 score streak points and unlock two score streaks at once.
Ideally, Treyarch is creating an environment that rewards team play just as much as individual play, something Infinity Ward tried with Modern Warfare 3 to modest success: people still play Domination for the kills. Once you unlock a score streak you'll have access to many devastating rewards, like the Guardian, a turret that sends out explosive player-stunning waves of energy. Then there's the AI-controlled tank that can also be controlled with a hold of the X button.
RC-XD
Unlocked At: 325 Pts
The RC-XD was also available as a Killstreak in Black Ops. This time round it's the lowest scorestreak available, and at 325 points to unlock, seems to be the equivilant of a 3-killstreak as in the original Black Ops.
As its name suggests -- XD stands for "Explosive Device" -- the RC-XD can be used to take out enemies as you control it to within proximity of an opponent for the explosive kill/s.
UAV
Unlocked at: 375 Pts
The UAV has been a Call of Duty staple since the good ol' days of CoD4. It's interesting that this score streak cames after the RC-XD, as any kill rewards are normally reserved for post-UAV streaks.
It's an especially useful weapon for team-based modes like Domination and Search & Destroy, and is a must-use technique for any players focused on big scores and not necessarily big kills.
It is somewhat vulnurable, however: enemies can shoot it down reletively easy using anti-air weaponry.
The Hunter Killer
Unlocked at: 400 Pts
The Hunter Killer appears to be Black Op 2's Predator Missile-equivilant. The main difference is that unlike the aforementioned you aren't sitting vulnurable while you guide it towards an enemy.
The Hunter Killer must be deployed from a location, at which it will seak out an enemy on its own and crash down onto them. This will probably be best used while a UAV is active so that you can deploy it while close to enemies.
Care Package
Unlocked at: 400 Pts
The care package first appeared in Modern Warfare 2 and was a staple in Modern Warfare 3. Players need to drop a marker for the package to be delivered to, and accessing the package leave you vulnurable on the ground. However, the occassional powerful reward more than makes it a worthy reward for hard work. Just be careful as to whether you call and access it.
Counter-UAV
Unlocked at: 475 Pts
This effective and useful reward allows you to jam enemy radar for 30 seconds. Most effective when an UAV or Advanced-UAV is in action for the enemy.
Just like the UAV, Counter-UAV can be shot down by anti-air weaponry.
Guardian
Unlocked at: 500 Pts
Official description from Treyarch's design director, David Vonderhaar:
"Suppress enemy movement with the brand new Guardian, a high-powered microwave dish that stuns and impairs enemies."
Seems like an ultra-powerful stun-like reward.
Hellstorm Missile
Unlocked at: 525 Pts
The Hellstorm Missile can be used one of two ways:
1. You can use it like a Predator Missile and take out one or multiple targets by guiding it to a specific area.
2. Split the missile up into a cluster of bombs, losing guidance of the missile but potentially earning yourself extra kills in the process.
Lightening Strike
Unlocked at: 550 Pts
This is a very similar reward to the Mortar Strike in the original Black Ops games.
The Strike will allow you to target three locations on the map, although little more else is known about this reward at this point. How the "strike" will actually come down onto enemies is unknown, but we can only assume it will be like a, erm, lightening strike.
Death Machine
Unlocked at: 600 Pts
This is returning from the original Black Ops. Here's an explanation from Black Ops 2 design director, David Vonderhaar.
"The Death Machine may be a little harder to earn this time around, but players now get to keep the devastating mini-gun for the duration of its massive ammunition supply."
Sentry Gun
Unlocked at: 650 Pts
An at-times devastating but easily destroyed reward, the Sentry Gun has become a CoD staple. It will work a little differently this time round, though: you'll be able to control the Sentry remotely if you wish, or leave it to do the work for you.
Either way, it's still a powerful and useful tool on the battlefield.
War Machine
Unlocked at: 700 Pts
This seemingly overpowered and devastating killstreak gives players access to a grenade launching beast that shoots out explosive round at a rapid, semi-automatic pace.
Dragonfire
Unlocked at: 725 Pts
The Dragonfire is a fully-controllable quad-rotor air drone that can fire down on enemies while hovering from above. It is vulnurable to anti-air weaponry.
AGR
Unlocked at: 800 Pts
The Autonomous Ground Robot (AGR) is similar to the Assault Drone from Modern Warfare 3.
Treyarch's description:
"When the Autonomous Ground Robot (A.G.R.) is brought into play, it breaks out of its airdrop container and instantly goes to work against the enemy. But at any time during its life, the owner can take over and remotely pilot this drone towards opposing troops."
Stealth Chopper
Unlocked at: 850 Pts
The Stealth Chopper has an advantage in Black Ops 2 in that it can't be seen on enemy radar, unlike in other Call of Duty games that feature a chopper killstreak.
It's unsure yet whether the stealth aspect will make it harder to take down, or whether it only makes it invisible on radar, but either way it will certainly be devastating.
Orbital VSAT
Unlocked at: 900 Pts
This reward is similar to the Advanced UAV in giving you an upgraded, more detailed version of the UAV.
It also cannot be shown down using anti-air weaponry. It will offer more locational and directional radar of enemies on the map.
Escort Drone
Unlocked at: 1000 Pts
This appears to be a lot like the AH-6 Overwatch killstreak that is a popular weapon in Modern Warfare 3. The Escort Drone will follow you around the map and take out nearby enemies.
Game designer, David Vonderhaar:
"One of my favorite AI-controlled Score Streaks is the escort drone – when you call it in, you hear it overhead, going to work for you and talking to you. You hear it target and eliminate targets, confirming it for you as it happens."
Warthog
Unlocked at: 1025 Pts
No, this is NOT a Halo 4 reference. The Warthog acts as heavy air support, acting as a gunship that includes both close air support for you and your team, as well as the occassional strafe run.
EMP
Unlocked at: 1050 Pts
After appearing in Modern Warfare 3, the powerful EMP returns to annoy opposing gamers everywhere. When deployed, the EMP disables all enemy electronics, including attachments like the Red Dot Sight, and any streak that might be active. Opposing players will be unable to deploy any streaks while the EMP fallout is still active.
Lodestar
Unlocked at: 1150 Pts
This devastating killstreak is new to the Call of Duty series, and will allow gamers to beam a laser target down onto the ground from above. It's unsure how many enemies at once you'll be able to target, how long this reward lasts for, or if it can easily be taken out with anti-air weaponry.
VTOL Warship
Unlocked at: 1150 Pts
This massive air ship can destroy enemies from above. It appears to be similar to the gunship killstreak in the first Black Ops. It will feature both guns and rockets.
Game designer, David Vonderhaar:
"And don’t even get me started about the VTOL aircraft – you literally rain steel on your enemies from above."
Canine Unit
Unlocked at: 1275 Pts
As was seen in World at War and Black Ops, the Canine Unit can be called in to unleash a bunch of murderous ravaging dogs on the enemy. Considering the high amount of points needed to unlock this Score Streak, we can assume that it will be far more effective in taking out enemies than it was in previous Call of Duty games.
Swarm
Unlocked at: 1400 Pts
This score streak is actually a swarm of Hunter Kill Drones. These drones swarm down onto enemies from above, taking them out in the process and acting as a devastating and rewarding killstreak.
Which Score Streaks are you most excited about?