Halo 3 Xbox 360 Unlockables

Finish the first mission of the Campaign on Normal, Heroic, or Legendary.

Finish the second mission of the Campaign on Normal, Heroic, or Legendary.

Finish the third mission of the Campaign on Normal, Heroic, or Legendary.

Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary.

Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary.

Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary.

Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary.

Finish the eigth mission of the Campaign on Normal, Heroic, or Legendary.

Finish the final mission of the Campaign on Normal, Heroic, or Legendary.

Finish the Campaign on Normal.

Finish the Campaign on Heroic (normal is unlocked as well).

Finish the Campaign on Legendary (normal and heroic are unlocked as well).

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.

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.

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.

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.

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

Earn 5 EXP or finish 10 games to complete the requirements for basic training (Online).

Earn your Sergeant rating to be recognized as a true Spartan (Online).

Advance to the Spartan Officer ranks (Online).

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

Destroy an enemy banshee with the spartan laser or missile pod in a ranked playlist or in campaign.

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

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

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

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

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

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

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

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

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

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

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

Locate and access all Terminals in the Campaign.

Earn the MVP in any ranked playlist (Online).

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

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

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 fourth mission.

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

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

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

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

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

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

Complete Tsavo Highway on Normal or higher

Complete Tsavo Highway on Legendary

Unlock "Too Close to the Sun" Achievement

Complete Tsavo Highway On Herioic or Legendary

Unlock "Up Close and Personal" Achievement

Unlock "Triple Kill" Achievement

Complete The Ark on Normal difficulty or higher.

Complete Campaign mode on Normal

Complete The Ark on Legendary difficulty

Complete Campaign mode on Legendary Difficulty

Earn 1000 Gamerscore points.

Unlock "Mongoose Mowdown" Achievement

Unlock "Used Car Salesman" Achievement

Unlock "UNSC Spartan" Achievement

Unlock "Spartan Graduate" Achievement

Unlock "Spartan Officer" Achievement

Complete The Ark on Heroic difficulty or higher.

Complete Campaign mode on Heroic difficulty.

Unlock "Overkill" Achievement

Unlock "Steppin' Razor" Achievement

Unlock "Overkill" Achievement

Collect 9 hidden skulls

Collect 13 hidden skulls

Collect 5 hidden skulls

Complete 49 Achievements for at least 1000 gamerscore

Get all the Vidmaster Achievements on Halo 3 and Halo 3: ODST

Get all the Vidmaster Achievements on Halo 3 and Halo 3: ODST

Get all the Vidmaster Achievements on Halo 3 and Halo 3: ODST

Hit and kill an opponent with a melee attack from behind.

Kill 5 opponents in a row without dying.

Kill 10 opponents in a row without dying.

Kill 15 opponents in a row without dying.

Kill an opponent after you have died.

Kill an opponent by using the Spartan Laser.

Kill an opponent by sticking him/her with a Plasma Grenade or a Spike Grenade.

Kill an opponent by using the Flamethrower.

End an opponent's killing spree’any spree.

Beat the opposing team by over 20 kills; (Luke owes you a steak dinner) (Secret Medal)

Hit and kill an opponent with a melee attack.

Get an overkill on the opposing team, wiping out all of the members.

Kill an opponent who is in the act of a sword lunge.

Kill 20 opponents in a row without dying.

Kill 25 opponents in a row without dying.

Kill 30 opponents in a row without dying.

Kill 2 opponents within 4 seconds of each other.

Kill 3 opponents within 4 seconds of each other.

Kill 4 opponents within 4 seconds of each other.

Kill 5 opponents within 4 seconds of each other.

Kill 6 opponents within 4 seconds of each other.

Kill 7 opponents within 4 seconds of each other.

Kill 8 opponents within 4 seconds of each other.

Kill 9 opponents within 4 seconds of each other.

Kill 10 opponents within 4 seconds of each other.

Kill an opponent with a headshot by using a sniping weapon.

Snipe 5 opponents in a row without dying.

Snipe 10 opponents in a row without dying.

Gun down 5 opponents with a Shotgun in a row without dying.

Gun down 10 opponents with a Shotgun in a row without dying.

Cut down 5 opponents with the Plasma Sword in a row without dying.

Cut down 10 opponents with the Plasma Sword in a row without dying.

Hit and kill an opponent with a vehicle.

Splatter 5 opponents in a row without dying.

Splatter 10 opponents in a row without dying.

Be the driver of a vehicle when a passenger kills an opponent.

Board an enemy ground vehicle.

Board an enemy aircraft.

Kill the opposing VIP in a VIP Gametype.

Plant the bomb in a Assault Gametype.

Kill the opposing bomb carrier in a Assault Gamtype.

Capture the opposing team's flag in a CTF gametype.

Kill 10 zombies in a row as a human without dying in an Infection gametype.

Kill 5 zombies in a row as a human without dying in an Infection gametype.

Kill 10 humans in a row as a zombie without dying in an Infection gametype.

Kill 5 humans in a row as a zombie without dying in an Infection gametype.

Be the last human of the game in an Infection gametype.

Kill 10 consecutive opponents in a single run as the Juggernaut in a Juggernaut gametype.

Kill 5 consecutive opponents in a single run as the Juggernaut in a Juggernaut gametype.

Kill the Juggernaut in a Juggernaut gametype.

Win a slayer game with 15+ kills without dying.

Get a melee kill when holding the ball in a Oddball gametype.

Kill 5 consecutive opponents in a single life from inside the hill before it moves in a King of the Hill gametype.

Get a melee kill with the flag in a CTF gametype.

Kill the opposing flag carrier in a CTF gametype.

Play in a matchmade game comprised of all Bungie.net users. (Secret Medal)

Skill Needed: 0 EXP:1

Skill Needed: 0 EXP:2

Skill Needed: 0 EXP:3

Skill Needed: 0 EXP:5

Skill Needed: 0 EXP:7

Skill Needed: 0 EXP:10

Skill Needed: 0 EXP:15

Skill Needed: 0 EXP:20

Skill Needed: 0 EXP:30

Skill Needed: 0 EXP:40

Skill Needed: 0 EXP:50

Skill Needed: 0 EXP:60

Skill Needed: 0 EXP:150

Skill Needed: 0 EXP:300

Skill Needed: 10 EXP:70

Skill Needed: 10 EXP:85

Skill Needed: 10 EXP:200

Skill Needed: 10 EXP:400

Skill Needed: 20 EXP:100

Skill Needed: 20 EXP:150

Skill Needed: 20 EXP:300

Skill Needed: 20 EXP:600

Skill Needed: 30 EXP:200

Skill Needed: 30 EXP:300

Skill Needed: 30 EXP:600

Skill Needed: 30 EXP:1,200

Skill Needed: 35 EXP:300

Skill Needed: 35 EXP:450

Skill Needed: 35 EXP:900

Skill Needed: 35 EXP:1,800

Skill Needed: 40 EXP:400

Skill Needed: 40 EXP:600

Skill Needed: 40 EXP:1,200

Skill Needed: 40 EXP:1,800

Skill Needed: 45 EXP:500

Skill Needed: 45 EXP:1,000

Skill Needed: 45 EXP:2,000

Skill Needed: 45 EXP:4,000

Skill Needed: 50 EXP:600

Skill Needed: 50 EXP:1,200

Skill Needed: 50 EXP:2,500

Skill Needed: 50 EXP:5,000

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.