- Askar
Score over 15,000 points in the Campaign meta-game on the fourth mission.
02 November 2007 - 4 guides
- Headshot Honcho
Kill 10 enemies with headshots in a ranked free for all playlist or in campaign.
30 October 2007 - 4 guides
- Spartan Officer
Advance to the Spartan Officer ranks (Online).
15 October 2007 - 7 guides
- Maybe Next Time Buddy
Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online).
09 October 2007 - 7 guides
- Mongoose Mowdown
Splatter an enemy with the mongoose in a ranked free for all playlist (Online).
09 October 2007 - 9 guides
- Two for One
Score a Double Kill with a single spartan laser shot in a ranked free for all playlist (Online).
09 October 2007 - 18 guides
- Guerilla
Score over 15,000 points in the Campaign meta-game on the first mission.
09 October 2007 - 5 guides
- Steppin' Razor
Score a Triple Kill with the sword in a ranked free for all playlist (Online).
08 October 2007 - 7 guides
- Overkill
Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
08 October 2007 - 9 guides
- Triple Kill
Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
08 October 2007 - 6 guides
- Campaign Complete: Legendary
Finish the Campaign on Legendary (unlocks achievements for Normal and Heroic, if not earned).
04 October 2007 - 17 guides
- Campaign Complete: Heroic
Finish the Campaign on Heroic (unlocks achievement for Normal, if not earned).
04 October 2007 - 2 guides
- UNSC Spartan
Earn your Sergeant rating to be recognized as a true Spartan (Online).
03 October 2007 - 2 guides
- Tilt
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
03 October 2007 - 4 guides
- Used Car Salesman
Destroy a vehicle that has three enemies in it in a ranked playlist or in campaign.
02 October 2007 - 7 guides
- Famine
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
02 October 2007 - 5 guides
- Fog
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
02 October 2007 - 4 guides
- Catch
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
02 October 2007 - 5 guides
- Tough Luck
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
02 October 2007 - 3 guides
- Iron
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
02 October 2007 - 3 guides
- MVP
Earn the MVP in any ranked playlist (Online).
01 October 2007 - 3 guides
- Killing Frenzy
Kill 10 enemies without dying in any ranked free for all playlist (Online).
01 October 2007 - 9 guides
- Lee R Wilson Memorial
Score 5 grenade sticks in any ranked free for all playlist (Online).
28 September 2007 - 8 guides
- Mythic
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
28 September 2007 - 3 guides
- Black Eye
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
28 September 2007 - 3 guides
- Graduate
Earn 5 EXP or finish 10 games to complete the requirements for basic training (Online).
27 September 2007 - 4 guides
- Up Close and Personal
Kill 5 enemies by melee or assassination in a ranked free for all playlist (Online).
27 September 2007 - 2 guides
- Campaign Complete: Normal
Finish the Campaign on Normal.
27 September 2007 - 1 guide
- Return
Finish the final mission of the Campaign on Normal, Heroic, or Legendary.
27 September 2007 - 1 guide
- The Key
Finish the eighth mission of the Campaign on Normal, Heroic, or Legendary.
27 September 2007 - 1 guide
- Last Stand
Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary.
26 September 2007 - 2 guides
- Thunderstorm
Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
26 September 2007 - 2 guides
- Fear the Pink Mist
Kill 5 enemies with the needler in a ranked free for all playlist or in campaign.
26 September 2007 - 6 guides
- Refuge
Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary.
26 September 2007 - 1 guide
- Cleansing
Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary.
26 September 2007 - 1 guide
- Assault
Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary.
25 September 2007 - 1 guide
- The Road
Finish the third mission of the Campaign on Normal, Heroic, or Legendary.
25 September 2007 - 1 guide
- Holdout
Finish the second mission of the Campaign on Normal, Heroic, or Legendary.
25 September 2007 - 1 guide
- Landfall
Finish the first mission of the Campaign on Normal, Heroic, or Legendary.
25 September 2007 - 1 guide
- Zombie Repeller
On a Mythic map, kill 2 Zombies during any ranked or social match.
23 September 2009 - 2 guides
- Delicious Brains
On a Mythic map, infect 2 humans during any ranked or social match.
23 September 2009 - 2 guides
- Tank Dropper
On any Mythic map, get a kill on another player while in monitor mode.
23 September 2009 - 13 guides
- … Get the Horns
On a Mythic map, get a Bulltrue medal during any ranked or social match.
23 September 2009 - 14 guides
- Have Fun Respawning
On a Mythic map, get an Extermination during any ranked or social match.
23 September 2009 - 6 guides
- Save This Film
On a Mythic map, get a Perfection medal during any ranked or social match.
23 September 2009 - 9 guides
- Awww, Too Bad
On a Mythic map, get a Killjoy medal during any ranked or social match.
23 September 2009 - 2 guides
- Hammer Time
On Assembly, get 5 Hammer kills during any ranked or social match.
23 September 2009 - 4 guides
- Killtacular
On a Mythic map, get a Killtacular during any ranked or social match.
22 September 2009 - 11 guides
- Sandbox Skull
On Sandbox, find the hidden skull.
22 September 2009 - 10 guides
- Orbital Skull
On Orbital, find the hidden skull.
22 September 2009 - 5 guides
- Assembly Skull
On Assembly, find the hidden skull.
22 September 2009 - 4 guides
- Post Mortem
On Orbital, get 2 Death From the Grave medals during any ranked or social match.
Locked - 10 guides