Defiant: Was the last surviving uninfected player in a matchmade Infection game.
Anniversary: Infected 3 players in a single round in a matchmade Infection game.
Defiant: Prevented the attacking team from touching the flag in a matchmade 1-Flag CTF game.
Defiant: Assassinated a player that just exited Armor-Lock in a matchmade game.
Anniversary: Captured 10 skulls at once in a matchmade Headhunter game.
Anniversary: Killed the flag carrier with a Plasma Grenade in a matchmade game.
Anniversary: Performed a Beat Down on an enemy while using the Jetpack during a matchmade game.
Anniversary: Killed an enemy with their own grenade that was stuck to you in a matchmade game.
Anniversary: Earned 3 headshots in a row in a matchmade game.
Anniversary: Ran over 5 people with a vehicle in a matchmade game.
Defiant: Killed 3 players with the Oddball in a matchmade Oddball game.
Defiant: Captured two flags from an enemy capture zone in a matchmade Stockpile game.
Defiant: Returned two flags in a matchmade CTF game.
Purchased an item from the Armory that required the rank of Lt. Colonel.
Completed every mission in Halo: Reach alone, on Legendary.
Completed the Campaign on Legendary difficulty.
Reached the rank of Captain in the UNSC.
Noble 1: Killed a player at long range with the DMR in a matchmade Slayer game.
Advanced a Commendation to a Silver state.
Noble 1: Your team blew up the research facility in a matchmade Invasion game on Breakpoint.
Noble 1: Destroyed a vehicle using Armor Lock in a matchmade game.
Noble 1: Earned a Double Kill from the Grave in multiplayer Matchmaking.
Noble 1: Your team collected all of the flags in a matchmade Stockpile game.
Noble 1: Earned a Double Kill with the shotgun in multiplayer Matchmaking.
Noble 1: Earned a kill in a matchmade Rocket Race game.
Won a game of Invasion in the 1st phase.
Finished the 9th mission on Legendary with the Scorpion intact.
Hijacked a Banshee during the Reach Campaign.
Performed an Assassination against an Elite to survive a fall that would've been fatal.
Completed a Weekly Challenge.
Killed 2 vehicles at once with the Target Locator during the 3rd mission.
Killed 10 enemies in Firefight or Campaign with a supercombine explosion.
Scored 1,000,000 points in a Firefight game.
Completed a Firefight set on Legendary without dying.
Scored 200,000 points in a Firefight game.
Scored 50,000 points in a Firefight game.
Completed all of the Daily Challenges in a given day.
Completed the 10th mission on Normal or harder.
Completed the Campaign on Heroic difficulty.
Completed the Campaign on Normal difficulty.
Completed the 9th mission on Normal or harder.
Killed 3 of the anti-aircraft batteries during the 8th mission.
Earned a Killionaire medal in Firefight.
Earned a Triple Kill while Jetpacking in Campaign, Firefight or Matchmaking.
Cleared the 2nd mission without setting foot in a drivable vehicle.
Killed 7 Moa during the 2nd mission of the Campaign.
Completed the 8th mission on Normal or harder.
Completed the 7th mission on Normal or harder.
Killed 10 enemies in a Firefight or Campaign session with the M6G pistol.
Completed the 6th mission on Normal or harder.
Destroyed the Corvette's engines & escort in under 3 minutes in the 6th mission on Heroic or harder.
Scored 15,000 points in Score Attack Firefight Matchmaking.
Completed the 5th mission on Normal or harder.
Killed the Elite Zealot before he escaped during the 5th mission.
Performed an Assassination on an enemy.
Earned a First Strike Medal in a Matchmaking game.
Used the File Browser to upload a file to your File Share.
As an Elite, killed 5 Spartan players in Matchmaking.
Let a teammate spawn on you 5 times in an Invasion Matchmaking game.
Reached the rank of Corporal in the UNSC.
Earned a Killing Spree in multiplayer Matchmaking.
Completed the 4th mission on Normal or harder.
Completed the 3rd mission on Normal or harder.
Traded weapons with an AI ally in Campaign.
Completed the 2nd mission on Normal or harder.
Killed 10 enemies in a Firefight or Campaign session with the DMR.
Used a Health Pack to replenish life after taking body damage.
Recommended a file to someone.
Purchased an item from the Armory.