Gamerscore

A Gamerpoint is an award given in a numerical value shown on your gamertag. You attain gamerpoints after completing special tasks in a game, otherwise known as achievements. In some games, gaining a certain amount of gamerpoints unlocks something in the game, such as armor or new weapons, or gaining a certain number of gamerpoints can also gain achievements in some games. While most games have 1000 gamerpoints in total, some games (eg. Xbox Live Arcade games) have far less than 1000 gamerpoints. Also, some games are not shipped with 1000 gamerpoints, but offer achievements as downloadable content. It is also called a "Gamerscore" by most people. Normally a game has 1000 gamerpoints but if an expansion pack is released more can be added on.

Note: These are not to be confused with "Microsoft Points", a stored-value system used for purchasing content on Xbox Live.

Achievments and Gamerpoints
Landfall - 20 points. Finish the first mission of the Campaign on Normal, Heroic, or Legendary.

Holdout - 20 points. Finish the second mission of the Campaign on Normal, Heroic, or Legendary.

The Road - 20 points. Finish the third mission of the Campaign on Normal, Heroic, or Legendary.

Assault - 30 points. Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary.

Cleansing - 30 points. Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary.

Refuge - 30 points. Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary.

Last Stand- 40 points. Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary.

The Key - 40 points. Finish the eighth mission of the Campaign on Normal, Heroic, or Legendary.

Return - 50 points. Finish the final mission of the Campaign on Normal, Heroic, or Legendary.

Campaign Complete: Normal- 125 points. Finish the Campaign on Normal.

Campaign Complete: Heroic- 125 points. Finish the Campaign on Heroic [unlocks achievement for Normal, if not earned].

Campaign Complete: Legendary - 125 points. Finish the Campaign on Legendary [unlocks achievements for Normal and Heroic, if not earned].

Iron - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Black Eye - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Tough Luck - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Catch - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Fog - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Famine - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Thunderstorm - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Tilt - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Mythic - 10 points. Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.

Spartan Program Recruit - 10 points. Win your first game in matchmaking to sign up for the Spartan Program Online.

UNSC Spartan - 15 points. Earn your Sergeant rating to be recognized as a true Spartan Online.

Spartan Officer - 25 points. Advance to the Spartan Officer ranks Online.

Two for One - 5 points. Score a Double Kill with a single spartan laser shot in a ranked free for all playlist Online.

Too Close to the Sun - 5 points. Destroy an enemy banshee with the spartan laser or missile pod in a ranked playlist or in campaign.

Triple Kill- 5 points. Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist Online.

Overkill - 5 points. Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist Online.

Lee R Wilson Memorial- 5 points. Score 5 grenade sticks in any ranked free for all playlist Online.

We’re in for some Chop- 5 points. Destroy an enemy vehicle with equipment in a ranked playlist or in campaign.

Killing Frenzy- 5 points. Kill 10 enemies without dying in any ranked free for all playlist Online.

Steppin' Razor - 5 points. Score a Triple Kill with the sword in a ranked free for all playlist Online.

Mongoose Mowdown - 5 points. Splatter an enemy with the mongoose in a ranked free for all playlist Online.

Up Close and Personal- 5 points. Kill 5 enemies by melee or assassination in a ranked free for all playlist Online.

Fear the Pink Mist- 5 points. Kill 5 enemies with the needler in a ranked free for all playlist or in campaign.

Headshot Honcho - 5 points. Kill 10 enemies with headshots in a ranked free for all playlist or in campaign.

Used Car Salesman - 5 points. Destroy a vehicle that has three enemies in it in a ranked playlist or in campaign.

Marathon Man - 40 points. Locate and access all Terminals in the Campaign.

MVP - 5 points. Earn the MVP in any ranked playlist Online.

Maybe Next Time Buddy- 5 points. Board the same vehicle within 10 seconds after being boarded in any free for all playlist Online.

Guerilla - 10 points. Score over [15,000] points in the Campaign meta-game on the first mission.

Demon - 10 points. Score over [15,000???] points in the Campaign meta-game on the second mission.

Cavalier - 10 points. Score over [15,000] points in the Campaign meta-game on the third mission.

Askar - 10 points. Score over [15,000] points in the Campaign meta-game on the fourth mission.

Exterminator - 10 points. Score over [15,000] points in the Campaign meta-game on the fifth mission.

Ranger - 10 points. Score over [15,000] points in the Campaign meta-game on the sixth mission.

Vanguard - 10 points. Score over [15,000] points in the Campaign meta-game on the seventh mission.

Orpheus - 10 points. Score over [15,000] points in the Campaign meta-game on eighth mission.

Reclaimer - 10 points. Score over [15,000] points in the Campaign meta-game on the final mission