Elite

Ascetic Body: Accomplish the “Up Close and Personal” achievement.

Ascetic Head: Accomplish the “Steppin’ Razor” achievement.

Ascetic Shoulders: Accomplish the “Overkill” achievement.

Commando Body: Accomplish the “Triple Kill” achievement.

Commando Head: Accomplish the “Overkill” achievement.

Commando Shoulders: Accomplish the “Killing Frenzy” achievement.

Flight Body: Successfully complete the “Tsavo Highway” mission on the Heroic or Legendary difficulty setting.

Flight Head: Successfully complete Campaign mode on the Heroic difficulty setting.

Flight Shoulders: Successfully complete “The Ark” mission on the Heroic or higher difficulty setting.

Spartan

EOD Body: Successfully complete the “Tsavo Highway” mission on the Legendary difficulty setting.

EOD Head: Successfully complete Campaign mode on the Legendary difficulty setting.

EOD Shoulders: Successfully complete “The Ark” mission on the Legendary difficulty setting.

EVA Body: Successfully complete the “Tsavo Highway” mission on the Normal or higher difficulty setting.

EVA Head: Successfully complete Campaign mode on the Normal difficulty setting.

EVA Shoulders: Successfully complete “The Ark” mission on the Normal or higher difficulty setting.

Mark V Head: Accomplish the “UNSC Spartan” achievement.

ODST Head: Accomplish the “Spartan Graduate” achievement.

Rogue Head: Accomplish the “Spartan Officer” achievement.

Scout Body: Accomplish the “Too Close to the Sun” achievement.

Scout Head: Accomplish the “Used Car Salesman” achievement.

Scout Shoulders: Accomplish the “Mongoose Mowdown” achievement.

Security Head: Earn 1000 Gamerscore points.

Security Shoulders: Earn 800 Gamerscore points.

Hayabusa Chest: Collect 6 Skulls
Hayabusa Helmet: Collect 13 Skulls
Hayabusa Shoulders: Collect 9 Skulls

Black Eye Skull: At the start of the “Crow’s Nest” mission, without moving anything, you can see a huge pipe above you. Walk up the stairs, then up the next set. Turn to your left and jump up on the shelf unit. Jump to the red cross beam, then up onto the pipe. Then, just walk to the end. Walk over the Black Eye Skull to collect it. You do not have to pick this Skull up, it does it automatically. The Skull description reads “Bash your way to better health.” When this Skull is active, your shield will instantly charge when you use melee attacks, and will not auto-recharge anymore.

Blind Skull: In the “Sierra 117″ mission, when you get to the area where you see the Phantom overhead (one of the marines will point it out), jump over the rocks, and keep following the path on the right. When you get to the cliff, there will be a rock over the side. The Skull is on the end of the rock. The Skull description reads “Shoot from the hip.” Note: This Skull has to be activated before you start a campaign map.

Catch Skull: In “The Storm” mission, go to where the first anti-air Wraith tank is located. There is a large gray cylinder in the that area on the ground on the far side from where you enter. The Skull is on the top of the silo. To get up there, perform a grenade jump off a Warthog or use a vehicle to push a large crate to the side of it; jump on the crate, then the silo. Note: Do not destroy the Wraith near the door or the Skull will disappear. The Skull description reads “Pull pin. Count to three. Throw.” When this Skull is active, every NPC will carry two grenades and throws them often.

Cowbell Skull: In “The Ark” mission, pick up a Grav Lift from the small building near where you fight the Scarab. Then, proceed through the level until you reach the second sloping hallway (stairway). You should see some partitioned risers (platforms) halfway down. The Skull is on the top level. Throw the Grav Lift on the right side of the hall so it lands on the fourth little green dot from the door. Then, run, jump, and use the Grav Lift to propel you to the top. You should reach a checkpoint just as you enter the room, so if you miss you can try again. When this Skull is active, explosive force is increased.

Famine Skull: In “The Ark” mission, when you first go into the valley to the right after the wrecked Phantom, look to your left to see a huge boulder. Use a Ghost to get to the side of the boulder that is closest to the bridge overhead. It is easy to pilot the Ghost up the side of the wall using the thrust. To get the Skull, pilot two Ghosts up the wall to the top of the bridge and stack them on top of one another next to the beam where the Skull is placed. Then, jump from the top of the Ghosts towards the Skull and land on the beam. The Skull description reads “Trust us. Bring a magazine.” When this Skull is active, dropped weapons will have very little ammunition compared to normal.

Fog Skull: In the “Floodgate” mission, as you are walking down from the anti-air gun you destroyed in the previous mission, there will be a ramp (next to a missile launcher). Around this ramp, there is a checkpoint. At this point, you should also hear a marine yelling, “There! Over There!”. Look up and to the right, directly at the roof of the building next to the missile launcher. There is a Flood form (not to be mistaken with the two other Flood forms jumping in front of you), which is holding the Skull. Kill him before he jumps, and he will drop the Skull down to the ground where you can retrieve it. Note: Correct timing is required because if you kill him too early, the Skull will get stuck on the roof. The Skull description reads “You’ll miss those eyes in the back of your head.” When this Skull is active, your motion sensor disappears.

Grunt Birthday Party Skull: In the “Crow’s Nest” mission, immediately after the first objective, while en route to the barracks, you will fall down to a pipe. Go to the end of that pipe, then look over the edge to find a small space a few feet below. Drop over, then quickly pull back to land under the floor you dropped from. The Skull is at the end of this area. When this Skull is active, it makes Grunts explode in confetti when they are headshot. There will also be some cheering, like a birthday party.

Iron Skull: In the “Sierra 117″ mission, after freeing Johnson and killing all the Covenant that come in the Phantoms, walk to the Pelican that arrives to pick you up. Face the cargo bay, but instead of going in, turn left and follow the path. Once you hit the wall, jump up to your right to eventually reach a walkway. Walk all the way to the end. Take a left, then a right. At the end of this, a little bit to the right is a dark corner. Press Up to turn your light on and you should see the Skull. If you cannot see it, you are probably standing on it. The Skull description reads “Death carries a heavy price…”. When this Skull is active, instead of losing 25 points when you die, you will lose 75.

IWHBYD Skull: In “The Covenant” mission, go to the last tower. Before you get to the Prophet of Truth, there are a series of bridges with Halos. Do not jump through any yet. First, kill the Prophet of Truth, and defeat the bridges of enemies. Then, jump through the Halos in this order, with “1″ being at the entrance and “7″ being the end near where the Prophet of Truth was located: 4, 6, 5, 4, 5, 3, 4. Alternately, jump through the Halos in the following order: 4, 5, 6, 5, 7, 6, 5, 4, 1, 2, 3, 2, 7, 2, 1, 3, 4, 6, 7, 5, 4, 5, 3, 4. This is much easier in Co-op mode with three or four people. This is the Halo theme if it was played on a phone by dialing the numbers. If done correctly, the Halos will start flashing, and the Skull will appear near the Prophet’s ramp. If the Halos do not flash, try again. The Skull description reads “But the dog beat me over the fence.” When this Skull is active, there is bonus dialogue throughout the game. IWHBYD stands for “I Would Have Been Your Daddy”, which is a level chapter from the original Halo. -From: crimsontwist

Mythic Skull: In the “Halo” mission, follow the normal path until you reach a cave. Follow the right wall until it branches off into a small path. At the end of this path is some rubble, and in front is the Skull. The Skull description reads “Coverage under the Covenant health plan.” When this Skull is active, you will get a 3x score multiplier for all kills.

Thunderstorm Skull: In “The Covenant” mission, after you shut down the first tower and get access to the Hornet, fly to the second tower (the one the Arbiter shut down). While walking up the stairs, go to the middle part that connects both, and there should be stairs leading up to a platform where the Skull is. The Skull description reads “Field promotions for everyone!” When this Skull is active, enemies will be much stronger.

Tilt Skull: In the “Cortana” mission, when in the circular type room with all the Flood, look for a small structure piece next to two archways. Jump on top if it, then go up on the rocks to the top left. Turn left and jump up again, then turn 180 degrees and jump to the rocks across from you. Then, follow the rock sticking out and leading up on top of the original circular room. The Skull is in a pool of blood. The Skull description reads “What was once resistant is now immunity.” When this Skull is active, enemies will have different body parts that are resistance to certain bullet types.

Tough Luck Skull: In the “Tsavo Highway” mission, once you get past the part where you are forced to leave your vehicle, you will go through a tunnel and onto an open freeway. Immediately after coming out of the tunnel, you will see a huge pipe with two yellow ladders. Climb the second ladder. You should see a Regenerator power-up. Proceed to your right onto a small platform ledge where the yellow chain link fence is located. Jump onto that ledge, crossing over the fence. Directly behind you should be a large column that is holding up the giant pipe you were just on. Below that is a walkway. Fall off the ledge onto the walkway. Walk to the end of that. You should see a hidden ledge with the Skull on it. A few attempts may be requires to jump across. The Skull description reads “Your foes always make every saving throw.”

The Ark

1. Start the mission, then once you enter the first building, go left into another door. You should now be in a curved corridor. On the inside is a Terminal.

2. After activating the bridge to let your comrades across the gap, turn 180 degrees, and you should see a Terminal (it does not open until you activate the bridge).

3. In the third building after defeating the Scarab, kill the group of sleeping Covenant, then follow the corridor downwards. Once you reach a door in front that is locked, immediately on the left there is an open door. Go through and walk straight off, then turn 180 degrees to find a secret room with a Terminal.

The Covenant

4. When in the first tower standing on the lift, face the access panel and turn left. Jump over to find a Terminal.

5. Land your Hornet on the second tower, walk towards the entrance, but when you see the locked door, turn 180 degrees. A Terminal should be right in front of you.

6. When in the third tower standing on the lift, face the access panel and turn right. Jump over to find a Terminal.

Halo

7. After reaching the end of the first cave, follow the right wall, and you will see a building. Jump up on the walkway, then go left once inside to find a Terminal.

Get two Elephants to collide into each other. Have one flip the other over. When one is flipped over and you get close, the message “Hold RB to flip… wait, what? How did you do that?” will appear.

Drive the Elephant on a hill so it stays on it. Put exploding crates around the hanger. Blow up the crates with a plasma grenade. When it is flipped over and you get close, the message “Hold RB to flip… wait, what? How did you do that?” will appear. You can keep flipping it back and forth.

Landfall (20 points): Finish the first mission of the Campaign on Normal, Heroic, or Legendary.
Holdout (20 points): Finish the second mission of the Campaign on Normal, Heroic, or Legendary.
The Road (20 points): Finish the third mission of the Campaign on Normal, Heroic, or Legendary.
Assault (30 points): Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary.
Cleansing (30 points): Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary.
Refuge (30 points): Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary.
Last Stand (40 points): Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary.
The Key (40 points): Finish the eighth mission of the Campaign on Normal, Heroic, or Legendary.
Return (50 points): Finish the final mission of the Campaign on Normal, Heroic, or Legendary.
Campaign Complete: Normal (125 points): Finish the Campaign on Normal.
Campaign Complete: Heroic (125 points): Finish the Campaign on Heroic (unlocks achievement for Normal, if not earned).
Campaign Complete: Legendary (125 points): Finish the Campaign on Legendary (unlocks achievements for Normal and Heroic, if not earned).
Iron (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Black Eye (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Tough Luck (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Catch (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Fog (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Famine (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Thunderstorm (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Tilt (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Mythic (10 points): Find and claim this skull when playing on Normal, Heroic or Legendary difficulty.
Graduate (10 points): Earn 5 EXP or finish 10 games to complete the requirements for basic training (Online).
UNSC Spartan (15 points): Earn your Sergeant rating to be recognized as a true Spartan (Online).
Spartan Officer (25 points): Advance to the Spartan Officer ranks (Online).
Two for One (5 points): Score a Double Kill with a single Spartan laser shot in a ranked free for all playlist (Online).
Too Close to the Sun (5 points): Destroy an enemy Banshee with the Spartan laser or missile pod in a ranked playlist or in campaign.
Triple Kill (5 points): Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
Overkill (5 points): Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online).
Lee R Wilson Memorial (5 points): Score 5 grenade sticks in any ranked free for all playlist (Online).
We’re in for some Chop (5 points): Destroy an enemy vehicle with equipment in a ranked playlist or in campaign.
Killing Frenzy (5 points): Kill 10 enemies without dying in any ranked free for all playlist (Online).
Steppin’ Razor (5 points): Score a Triple Kill with the sword in a ranked free for all playlist (Online).
Mongoose Mowdown (5 points): Splatter an enemy with the mongoose in a ranked free for all playlist (Online).
Up Close and Personal (5 points): Kill 5 enemies by melee or assassination in a ranked free for all playlist (Online).
Fear the Pink Mist (5 points): Kill 5 enemies with the needler in a ranked free for all playlist or in campaign.
Headshot Honcho (5 points): Kill 10 enemies with headshots in a ranked free for all playlist or in campaign.
Used Car Salesman (5 points): Destroy a vehicle that has three enemies in it in a ranked playlist or in campaign.
Marathon Man (40 points): Locate and access all Terminals in the Campaign.
MVP (5 points): Earn the MVP in any ranked playlist (Online).
Maybe Next Time Buddy (5 points): Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online).
Guerilla (10 points): Score over 15,000 points in the Campaign meta-game on the first mission.
Demon (10 points): Score over 15,000 points in the Campaign meta-game on the second mission.
Cavalier (10 points): Score over 15,000 points in the Campaign meta-game on the third mission.
Askar (10 points): Score over 15,000 points in the Campaign meta-game on the fourth mission.
Exterminator (10 points): Score over 15,000 points in the Campaign meta-game on the fifth mission.
Ranger (10 points): Score over 50,000 points in the Campaign meta-game on the sixth mission.
Vanguard (10 points): Score over 50,000 points in the Campaign meta-game on the seventh mission.
Orpheus (10 points): Score over 15,000 points in the Campaign meta-game on the eighth mission.
Reclaimer (10 points): Score over 15,000 points in the Campaign meta-game on the final mission.