Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online).

Splatter an enemy with the mongoose in a ranked free for all playlist (Online).

True veteran of many battles, you are a Spartan Officer.

Score a Triple Kill with the sword in a ranked free for all playlist (Online).

Score a Double Kill with a single spartan laser shot in a ranked free for all playlist (Online).

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

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

Destroyed a vehicle that has three enemies in it in a ranked playlist or in campaign.

Score over 15,000 points in the Campaign meta-game on the second mission.

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

Score over 50,000 points in the Campaign meta-game on the seventh mission.

Score over 50,000 points in the Campaign meta-game on the sixth mission.

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

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

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

Destroy an enemy vehicle with equipment in a ranked playlist or in campaign.

Finish the Campaign on Legendary (unlocks achievements for Normal and Heroic, if not earned).

Completed the Campaign on Heroic difficulty.

Completed the Campaign on Normal difficulty.

Completed the final mission of the Campaign.

Locate and access all Terminals in the Campaign.

Claimed Mythic skull.

Completed the eighth mission of the Campaign.

Claimed Tilt skull.

Completed the seventh mission of the Campaign.

Claimed Thunderstorm skull.

Completed the sixth mission of the Campaign.

Claimed Famine skull.

Completed the fifth mission of the Campaign.

Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.

Completed the fourth mission of the Campaign.

Destroyed a banshee with the spartan laser or missile pod in a ranked playlist or in campaign.

Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.

Completed the third mission of the Campaign.

Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.

Kill 10 enemies without dying in any ranked free for all playlist (Online).

Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online).

Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.

Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.

Kill 10 enemies with headshots in a ranked free for all playlist or in campaign.

Promoted to Sergeant. Proven in combat, you are a Spartan.

Score 5 grenade sticks in any ranked free for all playlist (Online).

Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist (Online).

Completed the second mission of the Campaign.

Completed the first mission of the Campaign.

Kill 5 enemies with the needler in a ranked free for all playlist or in campaign.

Earned the MVP in a ranked playlist.

Graduated from basic training. Stick with it to earn your Spartan Insignia.

Kill 5 enemies by melee or assassination in a ranked free for all playlist (Online).

After 9/25/08, complete Halo on 4-player Legendary LIVE co-op, with Iron, and everyone in Ghosts.

On a Legendary map, get two Double Kills during any ranked or social match.

On a Legendary map, get 3 Oddball melee kills during any ranked or social match.

On a Legendary map, get 3 assassinations during any ranked or social match.

On a Legendary map, get a flag melee kill during any ranked or social match.

On a Legendary map, get 2 flag carrier kills during any ranked or social match.

On a Legendary map, get 5 Warthog chaingun kills during any ranked or social match.

On a Legendary map, get a Splatter Spree during any ranked or social match.

On Assembly, get 5 Hammer kills during any ranked or social match.

On Citadel, get a Shotgun Spree during any ranked or social match.

On Heretic, get a Sword Spree during any ranked or social match.

On Longshore, get 3 kills with a Ghost during any ranked or social match.

On Orbital, get 2 Death From the Grave medals during any ranked or social match.

On a Mythic map, get a Bulltrue medal during any ranked or social match.

On a Mythic map, get a Killjoy medal during any ranked or social match.

On a Mythic map, get a Killtacular during any ranked or social match.

On a Mythic map, get an Extermination during any ranked or social match.

On a Mythic map, get a Perfection medal during any ranked or social match.

On a Mythic map, infect 2 humans during any ranked or social match.

On a Mythic map, kill 2 Zombies during any ranked or social match.

On any Mythic map, get a kill on another player while in monitor mode.

On Assembly, find the hidden skull.

On Citadel, find the hidden skull.

On Heretic, find the hidden skull.

On Longshore, find the hidden skull.

On Orbital, find the hidden skull.

On Sandbox, find the hidden skull.

Find all the hidden skulls on the Mythic maps.

Get to the rank of Lieutenant in any playlist in the new EXP progression system.

Enter into any ranked or social playlist with 7 EXP on the 7th of the month.