Overkill
5Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
Unlocked: 21 Aug 2010 23:25:08
Score a Double Kill with a single spartan laser shot in a ranked free for all playlist (Online).
Unlocked: 21 Aug 2010 22:39:26
Kill 10 enemies without dying in any ranked free for all playlist (Online).
Unlocked: 21 Aug 2010 21:03:54
Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online).
Unlocked: 21 Aug 2010 21:01:44
Score a Triple Kill with the sword in a ranked free for all playlist (Online).
Unlocked: 21 Aug 2010 20:34:43
Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
Unlocked: 21 Aug 2010 20:34:42
Splatter an enemy with the mongoose in a ranked free for all playlist (Online).
Unlocked: 21 Aug 2010 20:00:52
Reclaimer
10Score over 15,000 points in the Campaign meta-game on the final mission.
Unlocked: 19 Aug 2010 18:11:31
Orpheus
10Score over 15,000 points in the Campaign meta-game on the eighth mission.
Unlocked: 19 Aug 2010 17:34:06
Vanguard
10Score over 50,000 points in the Campaign meta-game on the seventh mission.
Unlocked: 19 Aug 2010 17:07:22
Ranger
10Score over 50,000 points in the Campaign meta-game on the sixth mission.
Unlocked: 30 Jul 2010 20:43:46
Exterminator
10Score over 15,000 points in the Campaign meta-game on the fifth mission.
Unlocked: 09 Feb 2010 18:17:25
Askar
10Score over 15,000 points in the Campaign meta-game on the fourth mission.
Unlocked: 08 Feb 2010 22:10:03
Score 5 grenade sticks in any ranked free for all playlist (Online).
Unlocked: 06 Feb 2010 18:04:08
Demon
10Score over 15,000 points in the Campaign meta-game on the second mission.
Unlocked: 02 Feb 2010 19:18:02
Guerilla
10Score over 15,000 points in the Campaign meta-game on the first mission.
Unlocked: 02 Feb 2010 18:45:27
Advance to the Spartan Officer ranks (Online).
Unlocked: 02 Feb 2010 00:29:36
Kill 5 enemies by melee or assassination in a ranked free for all playlist (Online).
Unlocked: 08 Jul 2009 15:08:27
UNSC Spartan
15Earn your Sergeant rating to be recognized as a true Spartan (Online).
Unlocked: 08 Jul 2009 03:43:29
Marathon Man
40Locate and access all Terminals in the Campaign.
Unlocked: 04 Jul 2009 01:21:43
Finish the Campaign on Legendary (unlocks achievements for Normal and Heroic, if not earned).
Unlocked: 03 Jul 2009 19:10:43
MVP
5Earn the MVP in any ranked playlist (Online).
Unlocked: 06 Mar 2009 01:06:53
Graduate
10Earn 5 EXP or finish 10 games to complete the requirements for basic training (Online).
Unlocked: 06 Mar 2009 00:43:08
Landfall
20Finish the first mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Holdout
20Finish the second mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
The Road
20Finish the third mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Assault
30Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Cleansing
30Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Refuge
30Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Last Stand
40Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
The Key
40Finish the eighth mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Return
50Finish the final mission of the Campaign on Normal, Heroic, or Legendary.
Unlocked: Offline
Finish the Campaign on Normal.
Unlocked: Offline
Finish the Campaign on Heroic (unlocks achievement for Normal, if not earned).
Unlocked: Offline
Iron
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Black Eye
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Tough Luck
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Catch
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Fog
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Famine
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Thunderstorm
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Tilt
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Mythic
10Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Unlocked: Offline
Destroy an enemy banshee with the spartan laser or missile pod in a ranked playlist or in campaign.
Unlocked: Offline
Destroy an enemy vehicle with equipment in a ranked playlist or in campaign.
Unlocked: Offline
Kill 5 enemies with the needler in a ranked free for all playlist or in campaign.
Unlocked: Offline
Kill 10 enemies with headshots in a ranked free for all playlist or in campaign.
Unlocked: Offline
Destroy a vehicle that has three enemies in it in a ranked playlist or in campaign.
Unlocked: Offline
Cavalier
10Score over 15,000 points in the Campaign meta-game on the third mission.
Unlocked: Offline
On a Legendary map, get 3 Oddball melee kills during any ranked or social match.
Unlocked: 22 Aug 2010 13:47:46
Flag Dropped
25On a Legendary map, get 2 flag carrier kills during any ranked or social match.
Unlocked: 21 Aug 2010 21:53:05
Defend This
50On a Legendary map, get a flag melee kill during any ranked or social match.
Unlocked: 21 Aug 2010 21:47:48
Road Rage
25On a Legendary map, get 5 Warthog chaingun kills during any ranked or social match.
Unlocked: 21 Aug 2010 17:07:18
On a Legendary map, get a Splatter Spree during any ranked or social match.
Unlocked: 25 Sep 2009 21:02:45
On a Legendary map, get two Double Kills during any ranked or social match.
Unlocked: 25 Sep 2009 20:13:20
On a Legendary map, get 3 assassinations during any ranked or social match.
Unlocked: 25 Sep 2009 20:11:57
Post Mortem
25On Orbital, get 2 Death From the Grave medals during any ranked or social match.
Unlocked: 23 Aug 2010 19:18:37
Hammer Time
25On Assembly, get 5 Hammer kills during any ranked or social match.
Unlocked: 23 Aug 2010 15:11:37
On a Mythic map, infect 2 humans during any ranked or social match.
Unlocked: 22 Aug 2010 13:19:00
On a Mythic map, kill 2 Zombies during any ranked or social match.
Unlocked: 22 Aug 2010 13:14:20
Killtacular
25On a Mythic map, get a Killtacular during any ranked or social match.
Unlocked: 30 Jan 2010 19:17:24
Tank Dropper
25On any Mythic map, get a kill on another player while in monitor mode.
Unlocked: 03 Oct 2009 19:24:49
On a Mythic map, get a Perfection medal during any ranked or social match.
Unlocked: 25 Sep 2009 20:50:43
On a Mythic map, get an Extermination during any ranked or social match.
Unlocked: 25 Sep 2009 20:08:35
On a Mythic map, get a Bulltrue medal during any ranked or social match.
Unlocked: 07 Jul 2009 16:16:32
On a Mythic map, get a Killjoy medal during any ranked or social match.
Unlocked: 07 Jul 2009 16:09:51
On Sandbox, find the hidden skull.
Unlocked: 02 Jul 2009 19:51:40
On Assembly, find the hidden skull.
Unlocked: 02 Jul 2009 18:54:24
On Orbital, find the hidden skull.
Unlocked: 02 Jul 2009 18:50:50
Ghost Patrol
25On Longshore, get 3 kills with a Ghost during any ranked or social match.
Unlocked: 25 Sep 2009 20:59:53
Pull
25On Citadel, get a Shotgun Spree during any ranked or social match.
Unlocked: 25 Sep 2009 20:18:34
On Heretic, get a Sword Spree during any ranked or social match.
Unlocked: 25 Sep 2009 20:08:57
On Citadel, find the hidden skull.
Unlocked: 25 Sep 2009 19:50:06
On Heretic, find the hidden skull.
Unlocked: 24 Sep 2009 14:28:19
On Longshore, find the hidden skull.
Unlocked: 24 Sep 2009 14:25:08
After 9/25/08, complete Halo on 4-player Legendary LIVE co-op, with Iron, and everyone in Ghosts.
Unlocked: 11 Jun 2011 13:31:03
Get to the rank of Lieutenant in any playlist in the new EXP progression system.
Unlocked: 02 Feb 2010 00:29:36
Find all the hidden skulls on the Mythic maps.
Unlocked: 25 Sep 2009 19:50:07
Enter into any ranked or social playlist with 7 EXP on the 7th of the month.
Unlocked: 07 Jul 2009 14:30:18