Cheats!!!!!!!!!!!!!!!!!

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SKULL: Blind! What does it do? Disables your heads-up display so you wont be able to veiw on-screen visuals such as your radar.
Where is it? This silver skull is found in mission 1: sierra 117. Near to the beginning of the mission, after the phantom has dropped off some troops, cross the stream and head to the rock face in front, then head left. You'll see the skull on an outcrop of a rock to get it.
Iron! What does it do? When you die you are returned to the begginning of the mission rather then the last checkpoint.
Where is it found? This gold skull is found in mission 1: sierra 117. its located right at the end of the mission, near to the building sarge has been imprisoned. Over on the right is a high ledge which you can reach by jumping onto some pipes. Once up follow the ledge to the far end and you'll find the skull hidden in the corner. 
Black Eye! What does it do? Your shield energy is recharged when you use melee attacks. forcing you to attack close up to survive!!!!!!
Where is it found? This gold skull is found in mission 2: Crows Nest. In the room whereyou begin the mission, look up and you'll see a metal pipe. jump up to this pipe using the racks and the red grider, then run along the pipe to find the skull. 
Grunt Birthday Party! What does it do?  Erm. Enemies explode into a shower of confetti and kids start cheering when you score a headshot. Biazarre!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Where is it found? This silver skull is found in mission 2: Crows Nest. Just before meeting the arbiter you must drop down a pipe. But instead of dropping all the way down, you stand at the end and look down- you'll see a secret passage running beneath the walkway you are standing on. Carefully drop into the passage which leads to the skull.  
 How to Unlock Landfall (20) Finish the first mission of the Campaign on Normal, Heroic, or Legendary. Holdout (20) Finish the second mission of the Campaign on Normal, Heroic, or Legendary. The Road (20) Finish the third mission of the Campaign on Normal, Heroic, or Legendary. Assault (30) Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary. Cleansing (30) Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary. Refuge (30) Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary. Last Stand (40) Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary. The Key (40) Finish the eigth mission of the Campaign on Normal, Heroic, or Legendary. Return (50) Finish the final mission of the Campaign on Normal, Heroic, or Legendary. Campaign Complete: Normal (125) Finish the Campaign on Normal. Campaign Complete: Heroic (125) Finish the Campaign on Heroic (normal is unlocked as well). Campaign Complete: Legendary (125) Finish the Campaign on Legendary (normal and heroic are unlocked as well). Iron (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Black Eye (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Tough Luck (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Catch (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Fog (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Famine (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Thunderstorm (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Tilt (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Mythic (10) Find and claim this skull when playing on Normal, Heroic or Legendary difficulty. Graduate (10) Earn 5 EXP or finish 10 games to complete the requirements for basic training (Online). UNSC Spartan (15) Earn your Sergeant rating to be recognized as a true Spartan (Online). Spartan Officer (25) Advance to the Spartan Officer ranks (Online). Two for One (5) Score a Double Kill with a single spartan laser shot in a ranked free for all playlist (Online). Too Close to the Sun (5) Destroy an enemy banshee with the spartan laser or missile pod in a ranked playlist or in campaign. Triple Kill (5) Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist (Online). Overkill (5) Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online). Lee R Wilson Memorial (5) Score 5 grenade sticks in any ranked free for all playlist (Online). We’re in for Some Chop (5) Destroy an enemy vehicle with equipment in a ranked playlist or in campaign. Killing Frenzy (5) Kill 10 enemies without dying in any ranked free for all playlist (Online). Steppin' Razor (5) Score a Triple Kill with the sword in a ranked free for all playlist (Online). Mongoose Mowdown (5) Splatter an enemy with the mongoose in a ranked free for all playlist (Online). Up Close and Personal (5) Kill 5 enemies by melee or assassination in a ranked free for all playlist (Online). Fear the Pink Mist (5) Kill 5 enemies with the needler in a ranked free for all playlist or in campaign. Headshot Honcho (5) Kill 10 enemies with headshots in a ranked free for all playlist or in campaign. Used Car Salesman (5) Destroy a vehicle that has three enemies in it in a ranked playlist or in campaign. Marathon Man (40) Locate and access all Terminals in the Campaign. MVP (5) Earn the MVP in any ranked playlist (Online). Maybe Next Time Buddy (5) Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online). Guerilla (10) Score over 15,000 points in the Campaign meta-game on the first mission. Demon (10) Score over 15,000 points in the Campaign meta-game on the second mission. Askar (10) Score over 15,000 points in the Campaign meta-game on the fourth mission. Exterminator (10) Score over 15,000 points in the Campaign meta-game on the fifth mission. Ranger (10) Score over 50,000 points in the Campaign meta-game on the sixth mission. Vanguard (10) Score over 50,000 points in the Campaign meta-game on the seventh mission. Orpheus (10) Score over 15,000 points in the Campaign meta-game on the eigth mission. Reclaimer (10) Score over 15,000 points in the Campaign meta-game on the final mission. Cavalier (10) Score over 15,000 points in the Campaign meta-game on the third mission. Armor Permutations Unlockables Body Pieces: Spartan marked with (S) and Elite marked with (E).

Unlockable How to Unlock (S) EVA Body Complete Tsavo Highway on Normal or higher (S) EOD Body Complete Tsavo Highway on Legendary (S) Scout Body Unlock "Too Close to the Sun" Achievement (E) Flight Body Complete Tsavo Highway On Herioic or Legendary (E) Ascetic Body Unlock "Up Close and Personal" Achievement (E) Commando Body Unlock "Triple Kill" Achievement (S) EVA Shoulders Complete The Ark on Normal difficulty or higher. (S) EVA Head Complete Campaign mode on Normal (S) EOD Shoulders Complete The Ark on Legendary difficulty (S) EOD Head Complete Campaign mode on Legendary Difficulty (S) Security Head Earn 1000 Gamerscore points. (S) Scout Shoulders Unlock "Mongoose Mowdown" Achievement (S) Scout Head Unlock "Used Car Salesman" Achievement (S) Mark V Head Unlock "UNSC Spartan" Achievement (S) ODST Head Unlock "Spartan Graduate" Achievement (S) Rogue Head Unlock "Spartan Officer" Achievement (E) Flight Shoulders Complete The Ark on Heroic difficulty or higher. (E) Flight Head Complete Campaign mode on Heroic difficulty. (E) Ascetic Shoulders Unlock "Overkill" Achievement (E) Ascetic Head Unlock "Steppin' Razor" Achievement (E) Commando Head Unlock "Overkill" Achievement (S) Hayabusa Shoulders Collect 9 hidden skulls (S) Hayabusa Helmet Collect 13 hidden skulls (S) Hayabusa Chest Collect 5 hidden skulls (S) Katana Complete 49 Achievements for at least 1000 gamerscore Multiplayer Ranks A list of the Skill and Experience needed to advance in rank. Note: you can skip ranks once there is a set skill requirement. For example, many people go from Lieutenant Grade 2 (Skill:10 EXP:85) straight to Captain (Skill:20 EXP:100)

Unlockable How to Unlock 01 Recruit Skill Needed: 0 EXP:1 02 Apprentice Skill Needed: 0 EXP:2 03 Apprentice Grade 2 Skill Needed: 0 EXP:3 04 Private Skill Needed: 0 EXP:5 05 Private Grade 2 Skill Needed: 0 EXP:7 06 Corporal Skill Needed: 0 EXP:10 07 Corporal Grade 2 Skill Needed: 0 EXP:15 08 Sergeant Skill Needed: 0 EXP:20 09 Sergeant Grade 2 Skill Needed: 0 EXP:30 10 Sergeant Grade 3 Skill Needed: 0 EXP:40 11 Gunnery Sergeant Skill Needed: 0 EXP:50 12 Gunnery Sergeant Grade 2 Skill Needed: 0 EXP:60 13 Gunnery Sergeant Grade 3 Skill Needed: 0 EXP:150 14 Gunnery Sergeant Grade 4 Skill Needed: 0 EXP:300 15 Lieutenant Skill Needed: 10 EXP:70 16 Lieutenant Grade 2 Skill Needed: 10 EXP:85 17 Lieutenant Grade 3 Skill Needed: 10 EXP:200 18 Lieutenant Grade 4 Skill Needed: 10 EXP:400 19 Captain Skill Needed: 20 EXP:100 20 Captain Grade 2 Skill Needed: 20 EXP:150 21 Captain Grade 3 Skill Needed: 20 EXP:300 21 Captain Grade 4 Skill Needed: 20 EXP:600 22 Major Skill Needed: 30 EXP:200 23 Major Grade 2 Skill Needed: 30 EXP:300 24 Major Grade 3 Skill Needed: 30 EXP:600 25 Major Grade 4 Skill Needed: 30 EXP:1,200 26 Commander Skill Needed: 35 EXP:300 27 Commander Grade 2 Skill Needed: 35 EXP:450 28 Commander Grade 3 Skill Needed: 35 EXP:900 29 Commander Grade 4 Skill Needed: 35 EXP:1,800 30 Colonel Skill Needed: 40 EXP:400 31 Colonel Grade 2 Skill Needed: 40 EXP:600 32 Colonel Grade 3 Skill Needed: 40 EXP:1,200 33 Colonel Grade 4 Skill Needed: 40 EXP:1,800 34 Brigadier Skill Needed: 45 EXP:500 35 Brigadier Grade 2 Skill Needed: 45 EXP:1,000 36 Brigadier Grade 3 Skill Needed: 45 EXP:2,000 37 Brigadier Grade 4 Skill Needed: 45 EXP:4,000 38 General Skill Needed: 50 EXP:600 39 General Grade 2 Skill Needed: 50 EXP:1,200 40 General Grade 3 Skill Needed: 50 EXP:2,500 41 General Grade 4 Skill Needed: 50 EXP:5,000 Multiplayer Medals If you do the following things you will get the medal while playing multiplayer. When you do the task usually it will show you by a little icon of the said medal appearing in the corner of the screen. Also at the end of each match you can check what medals you got. You can also check your overall medal count on bungie's official website. A very small amount of these are secret medals in that they don't tell you right when you get them but they will appear in your medal history. (One example of such a medal is the Steaktacular! Medal)

Unlockable How to Unlock Assassin! Hit and kill an opponent with a melee attack from behind. Killing Spree! Kill 5 opponents in a row without dying. Killing Frenzy! Kill 10 opponents in a row without dying. Running Riot Kill 15 opponents in a row without dying. Death from the Grave! Kill an opponent after you have died. Laser Kill! Kill an opponent by using the Spartan Laser. Grenade Stick! Kill an opponent by sticking him/her with a Plasma Grenade or a Spike Grenade. Incineration! Kill an opponent by using the Flamethrower. Killjoy! End an opponent's killing spree—any spree. Steaktacular! Beat the opposing team by over 20 kills; (Luke owes you a steak dinner) (Secret Medal) Beat Down! Hit and kill an opponent with a melee attack. Extermination! Get an overkill on the opposing team, wiping out all of the members. Bulltrue! Kill an opponent who is in the act of a sword lunge. Rampage! Kill 20 opponents in a row without dying. Untouchable! Kill 25 opponents in a row without dying. Invincible! Kill 30 opponents in a row without dying. Double Kill! Kill 2 opponents within 4 seconds of each other. Triple Kill! Kill 3 opponents within 4 seconds of each other. Overkill! Kill 4 opponents within 4 seconds of each other. Killtacular! Kill 5 opponents within 4 seconds of each other. Killtrocity! Kill 6 opponents within 4 seconds of each other. Killimanjaro! Kill 7 opponents within 4 seconds of each other. Killtastrophe! Kill 8 opponents within 4 seconds of each other. Killapocalypse! Kill 9 opponents within 4 seconds of each other. Killionaire! Kill 10 opponents within 4 seconds of each other. Sniper Kill! Kill an opponent with a headshot by using a sniping weapon. Sniper Spree! Snipe 5 opponents in a row without dying. Sharpshooter! Snipe 10 opponents in a row without dying. Shotgun Spree! Gun down 5 opponents with a Shotgun in a row without dying. Open Season! Gun down 10 opponents with a Shotgun in a row without dying. Sword Spree! Cut down 5 opponents with the Plasma Sword in a row without dying. Slice 'N Dice! Cut down 10 opponents with the Plasma Sword in a row without dying. Splatter! Hit and kill an opponent with a vehicle. Splatter Spree! Splatter 5 opponents in a row without dying. Vehicular Manslaughter! Splatter 10 opponents in a row without dying. Wheelman! Be the driver of a vehicle when a passenger kills an opponent. Highjacker! Board an enemy ground vehicle. Skyjacker! Board an enemy aircraft. Killed VIP! Kill the opposing VIP in a VIP Gametype. Bomb Planted! Plant the bomb in a Assault Gametype. Killed Bomb Carrier! Kill the opposing bomb carrier in a Assault Gamtype. Flag Score! Capture the opposing team's flag in a CTF gametype. Hell's Janitor! Kill 10 zombies in a row as a human without dying in an Infection gametype. Zombie Killing Spree! Kill 5 zombies in a row as a human without dying in an Infection gametype. Mmmm Brains! Kill 10 humans in a row as a zombie without dying in an Infection gametype. Infection Spree! Kill 5 humans in a row as a zombie without dying in an Infection gametype. Last Man Standing! Be the last human of the game in an Infection gametype. Unstoppable! Kill 10 consecutive opponents in a single run as the Juggernaut in a Juggernaut gametype. Juggernaut Spree! Kill 5 consecutive opponents in a single run as the Juggernaut in a Juggernaut gametype. Killed Juggernaut! Kill the Juggernaut in a Juggernaut gametype. Perfection! Win a slayer game with 15+ kills without dying. Oddball Kill! Get a melee kill when holding the ball in a Oddball gametype. Hail to the King! Kill 5 consecutive opponents in a single life from inside the hill before it moves in a King of the Hill gametype. Flag Kill! Get a melee kill with the flag in a CTF gametype. Killed Flag Carrier! Kill the opposing flag carrier in a CTF gametype. Linktacular! Play in a matchmade game comprised of all Bungie.net users. (Secret Medal) New Achievements As Of 9/23/08 Complete each achievement to get the allotted gamerscore. These Are The NEW Halo 3 Updated Achievements, Now You Can Get 1750G From Halo 3, Provided You Have The Legendary Map Pack.

Unlockable How to Unlock Vidmaster Challenge: Annual (0) After 9/25/08, complete Halo on 4-player Legendary LIVE co-op, with Iron, and everyone in Ghosts. Double Double (25) On a Legendary map, get two Double Kills during any ranked or social match. Alas, Poor Yorick (25) On a Legendary map, get 3 Oddball melee kills during any ranked or social match. Came… From… Behind (50) On a Legendary map, get 3 assassinations during any ranked or social match. Defend This (50) On a Legendary map, get a flag melee kill during any ranked or social match. Flag Dropped (25) On a Legendary map, get 2 flag carrier kills during any ranked or social match. Road Rage (25) On a Legendary map, get 5 Warthog chaingun kills during any ranked or social match. Look Both Ways (50) On a Legendary map, get a Splatter Spree during any ranked or social match. Hammer Time (25) On Assembly, get 5 Hammer kills during any ranked or social match. Pull (25) On Citadel, get a Shotgun Spree during any ranked or social match. Blades of Fury (25) On Heretic, get a Sword Spree during any ranked or social match. Ghost Patrol (25) On Longshore, get 3 kills with a Ghost during any ranked or social match. Post Mortem (25) On Orbital, get 2 Death From the Grave medals during any ranked or social match. … Get the Horns (25) On a Mythic map, get a Bulltrue medal during any ranked or social match. Awww Too Bad (25) On a Mythic map, get a Killjoy medal during any ranked or social match. Killtacular (25) On a Mythic map, get a Killtacular during any ranked or social match. Have Fun Respawning (25) On a Mythic map, get an Extermination during any ranked or social match. Save This Film (25) On a Mythic map, get a Perfection medal during any ranked or social match. Delicious Brains (25) On a Mythic map, infect 2 humans during any ranked or social match. Zombie Repeller (25) On a Mythic map, kill 2 Zombies during any ranked or social match. Tank Dropper (25) On any Mythic map, get a kill on another player while in monitor mode. Assembly Skull (25) On Assembly, find the hidden skull. Citadel Skull (25) On Citadel, find the hidden skull. Heretic Skull (25) On Heretic, find the hidden skull. Logshore Skull (25) On Longshore, find the hidden skull. Orbital Skull (25) On Orbital, find the hidden skull. Sandbox Skull (25) On Sandbox, find the hidden skull. Vidmaster Challenge: Brainpan (25) Find all the hidden skulls on the Mythic maps. Vidmaster Challenge: Lightswitch (0) Get to the rank of Lieutenant in any playlist in the new EXP progression system. Vidmaster Challenge: 7 on 7 (0) Enter into any ranked or social playlist with 7 EXP on the 7th of the month. How to get Recon Armor in Halo 3 To get Recon Armor (the whole set) you have to get the Vidmaster Achievements in Halo 3 and Halo 3: ODST. This includes for Halo 3 Annual, Brainpan, Lightswitch, and 7 on 7. For Halo 3: ODST they are Classic, Deja Vu, and Endure.