XBOX 360-Halo 3

Lower weapon
During a local match or replay, click Left Analog-stick + LB+ RB + A + Down for approximately three seconds. If done correctly, your weapon will not be visible on your screen. When you shoot, your weapon will be raised again. -From: Dirttbagg and darthvader302
Show coordinates
During a local match or replay, click Left Analog-stick + click Right Analog-stick + LB + RB + Down/Right.
Toggle panning camera
During a local match or replay, click Left Analog-stick + click Right Analog-stick + LB + RB + Up/Left.
Infinite Spartan laser in Halo mission
Use the following trick to get a Spartan laser with unlimited ammunition in the "Halo" mission. Play through the level until you meet up with Sergeant Johnson. Shoot him until he falls down and drops the Spartan laser. Quickly pick it up, and shoot it at him. Keep shooting him until he kills you. When you respawn, knock him down again, and pick up his laser. He should get back up with another laser on his back. When he does, shoot him down again, and pick up the new gun he drops. This laser should now have unlimited Spartan ammunition. This makes it easier to destroy the Guilty Spark 343. -From: Camuel
Katana
Successfully complete all achievements (1000/1000) and find all Skulls to unlock the Katana.
Recon armor (Mythic Map Pack DLC)
Get the three "Vid Master Challenge" achievements in the "Mythic Map Pack" bonus downloadable content to unlock the Recon armor.
Bonus downloadable content
Successfully complete the game on the Legendary difficulty to get bonus pictures and a "Making of" video from Xbox Live.
Alternate endings
There are three endings. The first ending is shown when the game is successfully completed on the Easy, Normal, or Heroic difficulty setting. The second ending is shown when the game is successfully completed on the Legendary difficulty setting. The third ending is shown when the game is successfully completed on the Legendary difficulty setting with all Skulls activated.
Easier Legendary mode
If you are playing alone on the Legendary difficulty setting, turn on an idle second player to stay behind. If you die, you will respawn instead of restarting.
Super fast Spartan laser fire
In Forge mode, get a Spartan laser. Charge it until it is almost about to fire. Before you fire, turn into the Monitor. Fly around until you find a target. Before you turn back into a human, hold RT to fire the Spartan laser almost instantly (if done correctly). You can use the Monitor's aimer to aim the laser.
Smarter respawning
When playing in Co-op mode on the Legendary difficulty setting, it is best to have one player keep their distance from the enemy at all times. By doing this, if the rest of the players die, they will respawn around the player that is farther back, rather than having to restart at the checkpoint.
Preventing lag
To clear the hard drive cache and prevent lag in Solo and Multiplayer mode, when starting the game, hold A + Up. Select "Yes" when you are asked if you want to clear the cache.
Easy experience in Multiplayer mode
Note: This trick requires four active accounts on your console that are all able to play on Xbox Live. Enter the matchmaking lobby, and choose "Social", then "Rumble Pit". Sign all four of your accounts in the lobby. In free for all modes, you have to be in the top three to earn experience points. Start matchmaking, and it should find two additional players. Once the game begins, you can simply do nothing. Once the game ends, all four of your accounts will tie for third place, giving all of them easy experience points. -From: Brandon Adkins
Getting in the same ranked Lone Wolves game
Go to the Xbox 360 Dashboard. Change your language to the second option from the bottom, then start Halo 3. Invite four other friends that are about the same rank as you, and have them change their language to the same one as you. Get everyone in the same party; everyone must search at the same time. Everyone must then make a game in Lone Wolves. Before you go to start the countdown, press X to change the search options to the bottom one, which is to search for the same language. If done correctly, you should be in the same ranked Lone Wolves game as your friends. You can now get achievements or level someone up.
Extra grenades
In Multiplayer or System Link mode, when you kill someone, slash their dead body with the Energy Sword for more grenades come out of it.
Armor permutations
Successfully complete the indicated task in Campaign mode to unlock the corresponding armor part in Multiplayer mode:
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: Accomplish the "Marathon Man" achievement in the Campaign Meta-game.
Hayabusa armor
Collect the indicated number of Skulls to unlock the corresponding piece of Hayabusa armor:
Hayabusa Chest: Collect 6 Skulls
Hayabusa Helmet: Collect 13 Skulls
Hayabusa Shoulders: Collect 9 Skulls
Skull locations
You can only collect Skulls on the Normal, Heroic, and Legendary difficulty setting. You must start from the beginning of the mission. You will not be able to see the Skulls if you load from a checkpoint, unless doing so after dieing. In Co-op mode, as soon as one player picks the Skull up, all players will receive the achievement if there is one. Not all Skulls earn an achievement; only nine of them do. To use Skulls, press X at the lobby screen. This will give you a bonus multiplier for Co-op mode and go towards earning the Guerrilla, Demon, etc. achievements.
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.
Alternately, take a Warthog, and park the front of it next to the cylinder. Take out a grenade (plasma recommended), and throw it at the front of the Warthog. Jump at the correct moment (usually as soon as you throw it) to get a little extra boost to your jump to get to the top to reach the Skull. This may require a few attempts.
Alternately, play in Co-op mode. Have a partner stand beside the building the Skull is on. Jump on top of them, then have them jump. At the peak of their jump, jump off of them. You will land next to the Skull. Collect it, then drop down to allow everyone else to get it.
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.
Use the following trick instead of trying to get a Ghost to the Famine Skull or risking your life with a grenade. Instead of going straight to it, go the way you do later in the level with the tank. Kill all the enemies or until one drops a deployable cover. Go the way you would have. When you get over the hill, destroy the Ghosts. Go under the bridge. You will see a big rock with a pathway leading up. Follow it. When you get to the top, turn to your right. It will not have a dirt ramp, but a wall. Walk up to it. Notice the small ledge. Jump up, and walk all the way to the right. Deploy the cover so that it lands about halfway down to where the bridge slopes. Do not throw too far or it go over the ledge. Jump on top of the cover. Jump up to the narrow ledge to get the Skull. Note: There is more than one way to jump from cover to ledge; try a few if you miss.
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 following Skulls require the "Mythic Map Pack" bonus downloadable content:
Assembly Skull: Located on the central tower in Forge.
Orbital Skull: Go to where there are two roadblocks where you have to jump. The Skull is on top of the structure on the right.
Sandbox Skull: Fly towards the sunset, and turn around to find the Skull.
Terminal locations
The following is a list of all seven Terminal locations. To accomplish the "Marathon Man" achievement, when you find each Terminal, press RB to view the journal. The screen will eventually start to turn red. Wait until it turns blue again and a new entry will appear. You need to view both entries in all Terminals for it to count towards the "Marathon Man" achievement. -From: Jared
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.
Multiplayer medals
Successfully complete the indicated task in Multiplayer mode to unlock the corresponding medal. Once you unlock most medals, they will be displayed in the corner of the screen and at the end of the match. You can view all earned medals on Bungie's official website. Note: There are two medals (Linktacular and Steaktacular) which will not display a confirmation once you unlock them, but they will still appear in your medal history.
Assassin: Hit and kill an opponent with a melee attack from behind.
Beat Down: Hit and kill an opponent with a melee attack.
Bomb Planted: Plant the bomb in an Assault game type.
Bulltrue: Kill an opponent who is in the act of a sword lunge.
Death from the Grave: Kill an opponent after you have died.
Double Kill: Kill 2 opponents within 4 seconds of each other.
Extermination: Get an overkill on the opposing team, wiping out all of the members.
Flag Kill: Get a melee kill with the flag in a CTF game type.
Flag Score: Capture the opposing team's flag in a CTF game type.
Grenade Stick: Kill an opponent by sticking him/her with a Plasma Grenade or a Spike Grenade.
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 game type.
Hell's Janitor: Kill 10 zombies in a row as a human without dying in an Infection game type.
Highjacker: Board an enemy ground vehicle.
Incineration: Kill an opponent by using the Flamethrower.
Infection Spree: Kill 5 humans in a row as a zombie without dying in an Infection game type.
Invincible: Kill 30 opponents in a row without dying.
Juggernaut Spree: Kill 5 consecutive opponents in a single run as the Juggernaut in a Juggernaut game type.
Killapocalypse: Kill 9 opponents within 4 seconds of each other.
Killed Bomb Carrier: Kill the opposing bomb carrier in a Assault Gamtype.
Killed Flag Carrier: Kill the opposing flag carrier in a CTF game type.
Killed Juggernaut: Kill the Juggernaut in a Juggernaut game type.
Killed VIP: Kill the opposing VIP in a VIP game type.
Killimanjaro: Kill 7 opponents within 4 seconds of each other.
Killing Frenzy: Kill 10 opponents in a row without dying.
Killing Spree: Kill 5 opponents in a row without dying.
Killionaire: Kill 10 opponents within 4 seconds of each other.
Killjoy: End an opponent's killing spree -- any spree.
Killtacular: Kill 5 opponents within 4 seconds of each other.
Killtastrophe: Kill 8 opponents within 4 seconds of each other.
Killtrocity: Kill 6 opponents within 4 seconds of each other.
Laser Kill: Kill an opponent by using the Spartan Laser.
Last Man Standing: Be the last human of the game in an Infection game type.
Linktacular (secret medal): Play in a matchmade game comprised of all Bungie.net users.
Mmmm Brains: Kill 10 humans in a row as a zombie without dying in an Infection game type.
Oddball Kill: Get a melee kill when holding the ball in an Oddball game type.
Open Season: Gun down 10 opponents with a Shotgun in a row without dying.
Overkill: Kill 4 opponents within 4 seconds of each other.
Perfection: Win a slayer game with 15+ kills without dying.
Rampage: Kill 20 opponents in a row without dying.
Running Riot Kill 15 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.
Skyjacker: Board an enemy aircraft.
Slice 'N Dice: Cut down 10 opponents with the Plasma Sword in a row without dying.
Sniper Kill: Kill an opponent by using a sniping weapon.
Sniper Spree: Snipe 5 opponents in a row without dying.
Splatter: Hit and kill an opponent with a vehicle.
Splatter Spree: Splatter 5 opponents in a row without dying.
Steaktacular (secret medal): Beat the opposing team by over 20 kills.
Sword Spree: Cut down 5 opponents with the Plasma Sword in a row without dying.
Triple Kill: Kill 3 opponents within 4 seconds of each other.
Unstoppable: Kill 10 consecutive opponents in a single run as the Juggernaut in a Juggernaut game type.
Untouchable: Kill 25 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.
Zombie Killing Spree: Kill 5 zombies in a row as a human without dying in an Infection game type.
Multiplayer ranks
Get the indicated number of skill and experience points to advance to the corresponding rank. Note: You can skip ranks once there is a set skill requirement. For example, you can go from Lieutenant Grade 2 (Skill: 10, EXP: 85) straight to Captain (Skill: 20, EXP: 100)
1. Recruit: Skill: 0, EXP: 1
2. Apprentice: Skill: 0, EXP: 2
3. Apprentice Grade 2: Skill: 0, EXP: 3
4. Private: Skill: 0, EXP: 5
5. Private Grade 2: Skill: 0, EXP: 7
6. Corporal: Skill: 0, EXP: 10
7. Corporal Grade 2: Skill: 0, EXP: 15
8. Sergeant: Skill: 0, EXP: 20
9. Sergeant Grade 2: Skill: 0, EXP: 30
10. Sergeant Grade 3: Skill: 0, EXP: 40
11. Gunnery Sergeant: Skill: 0, EXP: 50
12. Gunnery Sergeant Grade 2: Skill: 0, EXP: 60
13. Gunnery Sergeant Grade 3: Skill: 0, EXP: 150
14. Gunnery Sergeant Grade 4: Skill: 0, EXP: 300
15. Lieutenant: Skill: 10, EXP: 70
16. Lieutenant Grade 2: Skill: 10, EXP: 85
17. Lieutenant Grade 3: Skill: 10, EXP: 200
18. Lieutenant Grade 4: Skill: 10, EXP: 400
19. Captain: Skill: 20, EXP: 100
20. Captain Grade 2: Skill: 20, EXP: 150
21. Captain Grade 3: Skill: 20, EXP: 300
21. Captain Grade 4: Skill: 20, EXP: 600
22. Major: Skill: 30, EXP: 200
23. Major Grade 2: Skill: 30, EXP: 300
24. Major Grade 3: Skill: 30, EXP: 600
25. Major Grade 4: Skill: 30, EXP: 1,200
26. Commander: Skill: 35, EXP: 300
27. Commander Grade 2: Skill: 35, EXP: 450
28. Commander Grade 3: Skill: 35, EXP: 900
29. Commander Grade 4: Skill: 35, EXP: 1,800
30. Colonel: Skill: 40, EXP: 400
31. Colonel Grade 2: Skill: 40, EXP: 600
32. Colonel Grade 3: Skill: 40, EXP: 1,200
33. Colonel Grade 4: Skill: 40, EXP: 1,800
34. Brigadier: Skill: 45, EXP: 500
35. Brigadier Grade 2: Skill: 45, EXP: 1,000
36. Brigadier Grade 3: Skill: 45, EXP: 2,000
37. Brigadier Grade 4: Skill: 45, EXP: 4,000
38. General: Skill: 50, EXP: 600
39. General Grade 2: Skill: 50, EXP: 1,200
40. General Grade 3: Skill: 50, EXP: 2,500
41. General Grade 4: Skill: 50, EXP: 5,000
Weapon descriptions
Assault rifle: This is a very handy weapon to fight all enemies with, but not vehicles. It is useful against both Covenant and Flood and is available throughout the game.
Pistol/Magnum: This is a very powerful dual-wielding gun that has high firing power. The new pistol no longer has a small zoom and has very little bullets. It is useful against both Covenant and Flood.
SMG: This is as powerful as in Halo 2. It has been upgraded with higher firing power and has a recoil. It is useful against both Covenant and Flood but can be difficult to find. It can be dual wielded.
Battle rifle: This is a powerful burst-firing rifle that has high damage and high accuracy. It is better against Covenant than Flood. It is useful for sniping.
Shotgun: This is a low ranged but powerful weapon. It can hold small amount of ammunition but can fire in mid-reload. It is useful against both Covenant and Flood but is far more efficient when used on the Flood.
Sniper rifle: This is an extremely long-ranged rifle that can fire four shots in one round. This is the main weapon for sniping and usually takes two shots to kill in the torso.
Rocket launcher: This is an extremely high damage weapon that is good for taking out powerful opponents and vehicles. It is also useful against groups of enemies. It has splash damage. Be careful as it can also be hazardous to yourself.
Spartan laser: This is the most powerful weapon in the game but requires a long charged wait. It is useful for killing vehicles and powerful enemies. It is vital to kill the Monitor.
Plasma rifle: This is a powerful weapon that is great against the Flood. You can dual-wield them, but they will overheat if fired for too long.
Plasma pistol: One fully powered shot can take out your shield. A powerful but difficult weapon to use. It can be dual-wielded. It is useful because of its high range and high attack speed. It is better against Covenant.
Brute spiker: This is a Brute weapon that is commonly used throughout the game. It has a medium-sized clip and can be dual-wielded. It is more powerful against Covenant.
Needler: This can no longer be dual-wielded but is much more powerful. It can now explode with four needles. It is useful against a group and powerful opponents.
Carbine: This is a Covenant version of a battle rifle. It is very useful for sniping and in close combat. It fires single shots and has an average round. It is commonly used by Jackals.
Brute shot: This is a less powerful splash weapon that is useful for taking out groups or vehicles. It has a high range and is very common throughout the game.
Beam rifle: This is a Covenant sniper-rifle. It does not require clips but cannot be fired repeatedly due to overheating. It has high range and is powerful against Brutes.
Energy sword: This is a melee weapon that is extremely powerful against one opponent, usually resulting in a one-hit kill. It is useful against both Covenant and Flood. It has a small rush towards the target before striking.
Gravity hammer: This is a rare and powerful melee weapon. It is only used by extremely powerful Brutes. It can take out groups and can push opponents away. It has a tiny rush when attacking.
Frag grenade: This is a powerful and dangerous grenade that has the highest kill-radius. It has a bounce that can make killing opponents difficult.
Plasma grenade: This is a weaker grenade that can stick to opponents and detonate, killing those around it. It sticks only to opponents.
Spike grenade: This is a less powerful but lethal version of the plasma grenade. When detonating, it sends spikes shooting in all directions. It can stick to both opponents and vehicles.
Firebomb grenade: This explodes on impact spreading flames around the area. It has a burning effect that is good against Flood more than Covenant but can spread.
Recharge shields quicker
If your shields are down in Forge mode, press Up and they will recharge.
Reload quicker
If you are a Spartan or Elite and your ammunition is low, press Up again while reloading to instantly reload.
Melee faster
To melee quicker, press B, then press Y(2), B rapidly.
Stay zoomed in
If you are zoomed in as a Spartan or Elite and turn into the Monitor, press Up to turn back into your character and still be zoomed.
Crouching
To crouch, click and hold the Left Analog-stick. While crouched, you will not appear on motion-sensors. This is helpful in Multiplayer mode when you do not want the other team to find out where you are.
Play as the Oracle
At the Forge lobby, press Up to turn into the Oracle. You can pick up items by pressing A when you see a green hand.
Exploding grenades
Throw a grenade in the air, and shoot it with a sniper rifle.
Defeating Flood
When you kill any Flood that can come back to life by the infection forms, hit the body and it should break apart. This saves ammunition.
Defeating Wraiths
To easily kill a Wraith and save time and ammunition, aim at the little circle on its back. It only takes approximately five to ten shots to kill it this way.
Illegal service tags
If you go to "Appearance" and try to change your service tag to "I17" (Master Chief's number is 117), the game will not allow it. It will say that the tag is reserved for use by the UNSC.
If you try to use "A55" as your service tag, you will be told that it cannot be used under UNCS regulations and rules.
Driving vehicles through invisible walls
In certain levels in Campaign mode, you may want to take your vehicle through most of the level. However, there are invisible walls that keep the vehicle from moving past where it is needed. To pass through this, drive your vehicle through the doorway, gate, tunnel, etc. where the invisible wall is located. Just before you go through it, jump out and let the vehicle pass through the wall. This allows you to take the vehicle through the rest of the level if desired.
Go under map in Construct multiplayer map
To do this trick, you must be in Forge mode. Make sure you sell a respawn point before doing this glitch. Start out as the Oracle. Go down the pink Grav Lift by using your boost (press LT). There should be a few holes. You cannot fit down these as the Oracle. Start boosting into one of the holes that is not a closed circle. The Oracle should go slightly lower into this hole. Make sure you keep holding boost, then turn into either Spartan or Elite. You should fall underneath the level. Make sure you drop a respawn maker on a place where you can stand so you can get back whenever desired. To confirm you are under the level, try to fly up without going through the Grav Lift. There is an invisible wall just like in the "Foundation" level in Halo 2, except on the bottom. Note: This may require a few attempts.
Dribble Skull in Crow's Nest mission
At the beginning of the mission, grab the Skull on top of the large pipe near the ceiling before you pick up any weapons. This is easier in Co-op mode. Press RT repeatedly. This will cause Master Chief to drop the Skull, but because he has no weapons, he will immediately pick it back up, making it appear as though he is dribbling the Skull like a basketball.
Red vs. Blue reference in Crow's Nest mission
When you begin the mission, you will find a large roadway with many Covenant forces. You are supposed to fight your way to a door that will lead you to a room with two turbine-like objects. Instead of going through this door, follow the road all the way to the end, killing all the Covenant on the way. Once you reach the end, there will be a Marine knocking on a door wanting to get in. If you listen closely, you can hear that it is actually an excerpt from Red vs. Blue where Simmons is talking to Griff trying to get into the base. Note: There is a different message for each difficulty setting:
Easy: None
Normal: Two Marines copying Red vs. Blue.
Heroic: Simmons and Griff from Red vs. Blue.
Legendary: Church and Caboose doing a "remake" of Simmons and Griff.
Leave level boundary in Highground multiplayer map
Go down to the beach area in Forge mode, and get in a Mongoose. Have the person in the Mongoose accelerate at the barrier. Afterwards, have the Wraith boost at the back of the Mongoose from a short distance. For a brief moment the Mongoose will be past the barrier. When this happens, get out. You will then be outside of Highground. This trick works in all ocean maps.
Evil duck in Isolation multiplayer map
In the "Isolation" multiplayer map, go to the Flood cave where the Ghost is located. Go in front of the Ghost, look up, and walk a short distance slowly. You will see a big smudge on its face, but look carefully for the duck's body. You can partly see its face and the horns on its head. This is related to the picture in Zanzibar in Halo 2.
Leave level boundary in Isolation multiplayer map
While in Forge mode, get as high as possible as the Monitor. Spawn a teleporter on the ground. Then, hug any wall while still being as high as possible, and spawn another teleporter. If the teleporter beneath you is lit up as it should be, turn back into a Spartan or Elite, then go through the it. You should now be outside the level boundary.
Stretchy Master Chief in Last Resort multiplayer map
While in Forge mode, move to the two Mongooses next to the building on the far side of the map from the beach. Change into the Monitor, and place six or more Fusion Coils near the side of the bridge coming out of the building. Change back to Master Chief, and stand on top of the coils. Position yourself so that when they detonate you will fly into the side of the bridge. This may require a few attempts. Then, end the game. Go to the theater and watch the movie. Play the explosion slowly by tapping A quickly to pause and restart the movie. If done correctly, upon impact Master Chief will stretch out.
Flipped Elephant message in Sandtrap multiplayer map
Note: This trick is best done with two players. In the "Sandtrap" multiplayer map in Forge mode, first try to get as many pre-placed Fusion Coils and Plasma Batteries before starting. Place as many Fusion Coils and Plasma Batteries as possible in front of an Elephant, then drive into the pile. Then, shoot at the pile until it explodes. It will either just jump a little, stand up on the rear, or turn all the way around. When you get close, the message "Hold RB to flip... wait, what? How did you do that?" will appear. -From: Matthew Garriga
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.
Breathing under water in Sierra 117 mission
At the end of the level, when the Pelican arrives after you have rescued Johnson, it destroys the two Covenant ships, one being above the water just outside of where Johnson is held. The other one is above the water in the place just before the Pelican lands. You can climb in. Once the Covenant ship is destroyed on the side where it picks you up, the debris that remains will float on the water. Jump onto it, and let it sink. After that, all you can do is just jump from one piece of debris to the other. If you touch the ground, you will die.
Monkeys with teddy bear in Sierra 117 mission
After you come into contact with the snipers in the woods, follow the left rock path to find a strange family of monkeys holding a teddy bear.
Hidden area in Tsavo Highway mission
After the part where you exit your Warthog, jump across the bridge, and kill the Brute and two Grunts that are attacking your men. Turn directly around, facing toward where you came from. Look to your left, and you will see a structure. Go up to the wall on the structure, and look to your right. There should be a pathway. Follow the path until you get on top of a bridge-like structure. There should be some dead UNSC Marines, a sniper rifle, and some other ammunition.
Crossing broken bridge with vehicles in Tsavo Highway mission
When you reach the bridge with a Warthog or other vehicle with barriers, normally you cannot cross this area. However, back in one of the buildings before the bridge is a Grav Lift. Get it, and throw it a bit before the break in the bridge, then run the Warthog or any other vehicle over it. This will make the next area much easier, especially on the Legendary difficulty setting.
Leave level boundary in Valhalla multiplayer map
Go to the ocean barrier (the side with the ocean). Then, you and another player must get a Mongoose and Wraith. Have one player drive the Mongoose into the barrier. Keep accelerating, and have the other player get into the Wraith. Drive behind the Mongoose inside the Wraith, and use the boost. You must be close for the Mongoose to go through. Once you hit it, the other player must jump out once he or she is pass the barrier.
Easy "Used Car Salesman" achievement
Go to the beginning of "The Ark" mission. Make sure you have a guest or a friend to help. Continue the mission until you reach where the crashed Pelican is found (after the first terminal). Kill the blue Brute, and grab the rocket launcher under the crashed Pelican. Continue to where the choppers are located. As you are moving, a Prowler will drive by. Ignore it because it will soon stop and abandon the Prowler leading to failure of the achievement. Another Prowler will follow. Have your guest or friend shoot it twice with a Brute Shot, then shoot at it with your rockets to get the achievement. Note: If you are by yourself, do the same thing, but instead of using a Brute Shot, throw a grenade in front of it. Then, shoot it with the rockets.
Achievements
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:
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.
Additionally, the following achievements are available on games patched after September 25, 2008:
Vidmaster Challenge: Annual (0 points): After 9/25/08, complete Halo on 4-player Legendary LIVE co-op, with Iron, and everyone in Ghosts.
Pull (25 points): On Citadel, get a Shotgun Spree during any ranked or social match.
Blades of Fury (25 points): On Heretic, get a Sword Spree during any ranked or social match.
Ghost Patrol (25 points): On Longshore, get 3 kills with a Ghost during any ranked or social match.
Citadel Skull (25 points): On Citadel, find the hidden skull.
Heretic Skull (25 points): On Heretic, find the hidden skull.
Longshore Skull (25 points): On Longshore, find the hidden skull.
The following achievements require the "Legendary Map Pack" bonus downloadable content:
Double Double (25 points): On a Legendary map, get two Double Kills during any ranked or social match.
Alas, Poor Yorick (25 points): On a Legendary map, get 3 Oddball melee kills during any ranked or social match.
Came... From... Behind (50 points): On a Legendary map, get 3 assassinations during any ranked or social match.
Defend This (50 points): On a Legendary map, get a flag melee kill during any ranked or social match.
Flag Dropped (25 points): On a Legendary map, get 2 flag carrier kills during any ranked or social match.
Road Rage (25 points): On a Legendary map, get 5 Warthog chaingun kills during any ranked or social match.
Look Both Ways (50 points): On a Legendary map, get a Splatter Spree during any ranked or social match.
The following achievements require the "Mythic Map Pack" bonus downloadable content:
Hammer Time (25 points): On Assembly, get 5 Hammer kills during any ranked or social match.
Post Mortem (25 points): On Orbital, get 2 Death From the Grave medals during any ranked or social match.
...Get the Horns (25 points): On a Mythic map, get a Bulltrue medal during any ranked or social match.
Awww, Too Bad (25 points): On a Mythic map, get a Killjoy medal during any ranked or social match.
Killtacular (25 points): On a Mythic map, get a Killtacular during any ranked or social match.
Have Fun Respawning (25 points): On a Mythic map, get an Extermination during any ranked or social match.
Save This Film (25 points): On a Mythic map, get a Perfection medal during any ranked or social match.
Delicious Brains (25 points): On a Mythic map, infect 2 humans during any ranked or social match.
Zombie Repeller (25 points): On a Mythic map, kill 2 Zombies during any ranked or social match.
Tank Dropper (25 points): On any Mythic map, get a kill on another player while in monitor mode.
Assembly Skull (25 points): On Assembly, find the hidden skull.
Orbital Skull (25 points): On Orbital, find the hidden skull.
Sandbox Skull (25 points): On Sandbox, find the hidden skull.
Vidmaster Challenge: Brainpan (25 points): Find all the hidden skulls on the Mythic maps.
Vidmaster Challenge: Lightswitch (0 points): Get to the rank of Lieutenant in any playlist in the new EXP progression system.
Vidmaster Challenge: 7 on 7 (0 points): Enter into any ranked or social playlist with 7 EXP on the 7th of the month.