Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Completed Episode 1 (10 points): Complete Episode 1: Iraq.
Completed Episode 2 (10 points): Complete Episode 2: Quarantine.
Completed Episode 3 (10 points): Complete Episode 3: Rachel.
Completed Episode 4 (10 points): Complete Episode 4: Counter Insurgency.
Completed Episode 5 (10 points): Complete Episode 5: Topside.
Completed Episode 6 (10 points): Complete Episode 6: Wrecked.
Threat Level Yellow (25 points): Complete all episodes on Yellow (easy) difficulty.
Threat Level Orange (35 points): Complete all episodes on Orange (medium) difficulty.
Threat Level Red (50 points): Complete all episodes on Red (hard) difficulty.
The Downward Spore (10 points): Bring down a Spore Tower.
I said Drop and Roll! (10 points): Bring down a Fire Brute.
Beware! Octopus Dog! (10 points): Kill more than 25 Drudge using only melee.
Rapture (20 points): Kill more than 250 Reborn.
Researcher (10 points): Collect a Dossier.
Master Delegator (20 points): Get the squad to help you get more than 250 Focus Fire Kills.
Professional Motivator (20 points): Get the squad to High Morale more than 20 times.
Investigator (50 points): Collect all Dossiers.
Hunter (20 points): Collect 25 Dossiers.
Small but mighty (10 points): Get more than 10 head shot kills with the pistol in Campaign.
Magic Bullets (10 points): Get 10 kills while the M4 is equipped in Campaign.
Long distance charges may apply (10 points): Get 5 kills while the Sniper Rifle is equipped in Campaign.
Meatseeker (10 points): Get more than 10 kills using the Antitank Launcher's target-lock in Campaign.
Geometry Kills (10 points): Get 5 kills with the Scatter Gun’s bouncing projectiles in Campaign.
Dodge This! (10 points): Get more than 10 kills by detonating the Plasma Rifle's projectile in Campaign.
Going for the Gusto! (25 points): Get more than 100 kills with each weapon.
The instrument of your doom! (50 points): Get more than 200 kills with each weapon.
Look upon my works and despair! (100 points): Get more than 400 kills with each weapon.
Home Field Advantage (10 points): Host an Xbox LIVE game of Blacksite versus (any game type).
Boot Camp (10 points): Compete in an Xbox LIVE game of Blacksite.
I Fear The Reaper (10 points): Complete a ranked match of Deathmatch.
We Fear The Reaper (10 points): Complete a ranked match of Team Deathmatch.
Probed (10 points): Complete a ranked match of Abduction.
...And Justice For All (10 points): Complete a ranked match of Capture The Flag.
Around The Block (10 points): Complete a round of every Xbox LIVE Ranked Match game type.
King Of The Block (25 points): Win a round of every Xbox LIVE Ranked Match game type.
Flag Feeler (10 points): Capture your first flag.
Flag Stealer (25 points): Capture more than 25 flags.
Flag Dealer (50 points): Capture more than 50 flags.
Always Remember Your First (10 points): Win your first ranked match.
Spoils of War (30 points): Win more than 25 ranked matches.
Vae Victus (55 points): Win more than 50 ranked matches!.
The Skulls Of The Vanquished (50 points): Get over 20 kills without dying in a single Versus match!.
Exposed (49 points): Play in a game with a Blacksite Virus Carrier.
Blacksite Virus Carrier (51 points): Finish first in a ranked match containing a Blacksite Virus Carrier.