Banshee In The Control Room - To get a Banshee inside the room where you fight Tartarus first get a Banshee. After the Scarab destroys the front door fly inside and go straight up as soon as you enter. It's easy to navigate to the next door, get out of your Banshee and make the door open, then get back in your Banshee and fly through. Once the Brutes come through the next door you can kill them or fly past them, but it is important that you are not in your Banshee when the cut scene starts to make sure it is there when you walk back.
Get a Scarab Gun - This is done on the level Metropolis and is easiest when done on Co-op. When you start out, cross the bridge. Take out every enemy and even your marines. When you're near the end, Cortana will say something about a "Welcome Party". Three Banshees and a few ghosts will appear. Take them all out. Then 2 Wraiths and 2 Banshees will appear. Take out both Wraiths, and only one Banshee. Have Player 1 continue through the tunnel, but have Player 2 stay outside and distract the Banshee. Once Player 1 reaches the area with the circular opening (a Jackal with a Beam rifle is present), take out the Jackal and head back to where Player 2 is. Here is the hard part. Get the Banshee to follow both players into the tunnel. Do not board it yet! The first few times it will come at you and fly back out, but stay where you are. It should come back after you. (If it doesn't, go back outside and try again). Eventually, you'll have to get it over two road blocks. Once it is past the second one, have both players stand near the entrance of the room where Player 1 took out the Jackal. It should fly at you and get stuck. Shoot off both of its wings so it can fit through. Have Player 1 walk slowly in front of the Banshee, making it follow him. Player 2 should be behind it, gently pushing it. Take it to the left and get ready to board it. As soon as you hit the checkpoint, the Elite in the Banshee will disappear. You only have about a second to get in before the Banshee also disappears. Both players should press X quickly. If done right, one of the players will be driving the Banshee! Take it outside and directly up. Very high in the sky are two skyscrapers with two bridges connecting them. In the middle of the bridge closest to you, there is something that looks like a plasma rifle. It's actually a Scarab gun! It has infinite ammo, so have fun. Just don't aim at the ground.....
Skip Banshee Flight in the level Arbitor - When you first get to fly the banshee, zoom towards the tower to your right. When you get closer, a nav-point will appear. Go to it and the game will automatically advance to that spot in the story. By doing this, you've skipped the grueling 20 minute-long Banshee flight. On the downside, however, you don't have much of a chance to grab a Fuel Rod Cannon.
Skip fight around the Delta Halo Tower - After the cutscene with the hologram Regret telling you how he will start the ring in Delta Halo, continue until you see a crate. Then jump on it, then onto the ledge. Walk around until it loads the checkpoint. You will have skipped the battle.
Skip Half of Outskirts - (From the beginning of the level where Master Chief is a little dazed). Go straight out the door in front of you that leads to the street. kill the grunts and take out the shield-bearing jackels. Head down the street towards the two dead ends. Look on your right and you will see two alleyways that will connect to each other in this little sort of "room" in the alley. Go into that room and look back towards the street. You will see a dirt mound that is in one of the corners. Get on the dirt mound and grenade jump up to the next ledge. Look left you will see another ledge (top of a building) you should be able to jump right up to the ledge, but probably not on the first try. When you are on the building you can continue jumping from building to building all of the way through sniper alley. Once you reach the building that says "Zanzibar" on it is the point were you cannot get any farther using this way. Once you are on the first building walk over to the edge of the building that faces the street. Look right and jump onto the building next to you. Keep working your way back and try to stay as close as you can to that side. You will eventually come to the free part of the level where if you look right you will see a Pelican come. If you had to look fight to see the pelican you are on the left side of the freeway. if you had to look left to see the pelican you are on the right side of the freeway. If you are on the left side of the free way go left until you see a street (on your right side) that is torn up and the end it looks like. Jump off of the freeway into that street and you can walk over the damaged part of the street ( a hillish type thing) And that will put you at the building that says "Zanzibar" on it. If you were on the side of the right side of the freeway then crouch jump onto the buildings in front of you. Look on your right you will see a place were the height of the roofs drop and a certain roof is orange and red. If you don't see it go right and a little bit forward until you find it. jump straight on to the roof. If you jump onto the slanted part an invisible barrier will block you from going up. once you are on the building go up the little slanted area (make sure it is the up hill one) You will see two air vent/air conditioning unit things on the roof jump on one of them and onto the next building. Head straight and you will see the building that says "Zanzibar" on it. It is a good idea to kill the Covenant unit below before jumping down. Then it is back to the normal level.
Skip Sniper Alley - On Outskirts, once you have killed The first hunter pair at the start of the level walk through the hole in the wall they created. Walk through and look around. There should a destroyed wall to the left of you. Jump on to it and make your way upward by carrying on jumping upwards, crouch jumping when necessary. You should eventually reach the roof tops (it may take a while to find and/or reach). From here, head toward the left hand side part of the roof tops. you should see part of the destroyed highway that the first Pelican flies along once it has picked up the Sgt. Jump onto this highway and walk across it. At the other side you should see a slope and in the distance the hotel where the next group of marines are pinned down. Jump off the hight way and walk up this slope to reach the hotel skipping the sniper alley.
Two hidden swords on Halo Delta and a Fight to Skip - On Halo Delta, get to the structure where you can't go any farther with the tank. As you enter into the area, go left up the ramp and then up the little ramp until you come to the large block butted up against the wall. This is where you jump up to get to the Envy Skull (consult for more detail). There is a secret entrance behind this large cube. I found the easiest way to move it was with the tank, although grenades do the trick just as well. You can drive the tank up there with a little patience. Aim at the WALL to the left of the stone, The explosion with slowly move the stone out of the way. Once the path is clear, walk up the dark ramp and there will be two dead grunts and two swords. There is also a high ledge in the next room that you can grenade jump up to, and then frag grenade jump up one more level—allowing you to skip the fight inside the structure.
"Why am I here?" Message in Beaver Creek - This easter egg is very simple. Go to Beaver Creek. Run to where the sniper rifle spawns. Jump up on to the ledge in front of you and push all of the rocks down. When you push the big rock down look at the wall that was behind of it. If you look carefully, you should see "Why am I here?" Scratched in to the wall. (Note: if you can not see it then back away from the wall some and it should look much clearer.)
Angry Mode - When you are the Master Chief trying to recover the index from the Prophet of Truth on the Covenant Holy City go until you reach the first outdoor area with dirt and vegetation. Take a right as you enter this room and run up to the wall past the gravity lift that leads up to the sniper point. Get on top of the wall by going up the dirt mound on your left. Follow the wall until you reach the floating skull called "Angry". This skull makes enemies fire at a faster rate.
Blind Mode - At the beginning of Outskirts jump on top of the light on top of the door with a crouch jump, then jump to the left platform. Turn to your left and go down the long dark corridor and pick up the skull; it will say blind and your screen will flash black for a while. In this mode you can not see your weapon, body, shields, ammo, or radar. To get rid of this feature use the following method: 1. Turn off your Xbox or Save and Quit. 2. Go to Campaign and select level and choose Cairo Station. 3. Skip the cinematics and then Save and Quit. 4. Go to Outskirts and your HUD is back.
Assassins Mode - A skull similar to the one that activates blind mode can be found if you Start on "Regret". After the first lift ride (before the first underwater elevator), grenade jump from the front awning of the lift to the ledge in front of you (the one with two turrets). Grenade jump AGAIN onto the next ledge. Make your way to the back of the building. On Easy, you'll only find the skull. On Legendary, however, 2 invisible Elites carrying swords just shake their heads wildly, ignoring you completely.
Envy Mode - On the level "Delta Halo" on Legendary Difficulty, Progress until you reach the area during the "Push through the covenant held ruins" where you have to clear a Landing Zone for the Pelican to drop weapons. You will know you are in the right area when Cortana says "they're pouring out of the center building". That area has Plasma turrets along its borders. A little bit after the left side turret you will see the outline of a door in a wall, but the door has a solid rock slab in it and a rock in front of it. Jump on the rock then jump to the ledge above the door then jump on the ledge to the left. Now jump onto the building with the sealed door using grenades. Atop the building you will find two dancing elites and the "Envy Skull". Pick up the envy skull and you will be able to use Active Camouflage like the Arbiter.
Famine Skull - After you get off of the slowly descending elevator in "The Oracle", you will come to a hallway where you see a handful of dead bodies. Continue into the next room, and you will be on the second floor of a room that has windows. When you enter this room, look to the right, and find the third pane of glass. It should be to the right of a wall that has some flood guts splattered on it. Shoot out this window, and either window directly across the room. If you look below you will see a platform that has four tall posts. On the far side of the room there is a column that is right in between the two windows, on the far side of the room. Turn on your active camo, and jump to the center platform. Jump on either of the posts on the far side of the platform and jump to the column between the windows. Make another jump through the window you shot out and make a left. Walk all the way to the end and you'll find four flood elites convulsing on the floor, with the Famine skull in the middle of them. When you have this skull all weapons will have less ammo.
Giant Soccer Ball - It's on the level "Metropolis" on any difficulty I do believe. Use the same method to get a Banshee through the tunnels as you would if you were getting the Scarab Gun (More info later). Now take your Banshee away from that half-dome thing and fly through the level using the same path you would as if you were walking. Once you get to the highway where the Warthogs are fighting the Ghosts, keep flying straight toward the half-demolished building. Fly into it and go to the bottom level. Behold! A giant soccer ball! It's great fun to mess around with, especially if you have the Scarab gun.
Grunts Birthday Party Mode - In the level Arbiter on Legendary. Once you get to the first banshee section, fly immediately straight down all the way to the bottom of the map. In one of the cracks where the large cylinders connect to the station. There will be a circle of grunts dancing around a skull. When you pick up the skull; it will say Grunt Birthday Party on the screen. Now when you kill an enemy with a headshot, they will blow up like a plasma grenade was stuck to them. To get rid of this feature use the same method as the blind mode.
Iron Mode - On the last Master Chief Level, on Legendary Difficulty, when you enter the final Gravity Lift, look up. A skull will pass through you extremely quickly so you must start holding X a bit before you actually pass it to grab hold of it. Once you grab the Iron Skull, Iron Mode will be activated. This skull causes you to go back to the last checkpoint when you die in co-op mode.
Messages on the Bomb - If you play multiplayer and hide with the bomb, then you probably have noticed this already. If you stand somewhere long enough, Master Chief will start to toss the bomb up and catch it. Eventually he will examine the bomb, and you can read what it says on the bottom. One message is "goodbye" and another is "xoxoxoxo".
Midship Bunny - On the level Midship, go to the top where the sword spawns. Now walk to the doorway which doesn't have a big roof. Look up and you should see an outline of a bunny!
Mythic Mode - In "Sacred Icon" there is a semi outdoor area which has the same type of area right next to it. There is a large sentinel in front of each one. Go past this area and down the piston and you'll be in a vary dark and dank flood infested area. There's a stack of 6 or 7 boxes as you enter the room. Use them to jump up to the landing above. There are a handful of alcoves on your right hand side. The skull is in the third alcove, floating above a dead human flood.
Posters at the Old Mambassa Crash Landing - After you crash land on Old Mambassa, you can see posters all around with the Master Chief from the demo and some grunt posters.
Rex (In Outskirts) - First start going towards the blind skull way but when you go up there take a left instead of a right and jump on the ledge, then crouch jump on top of another ledge (which would be right above the wreckage) then jump on the ledge across the wreckage then continue walking along the pathway until you reach the area with the sword sticking out of the ground (It's inside a broken rooftop), right next to it is a rock with the word REX written on it.
Sign on Zanzibar - On the beach on Zanzibar, you will see signs that say NO SWIMMING. Well, go to your Xbox dashboard, go to the Settings, Clock, and change every number you can to 7, then pop Halo 2 back into your Xbox and load it up. WARNING: Do not sign into Xbox Live, it resets your clock. Now go to Split-Screen and start a game on Zanzibar. Go to the beach and look at the sign, it will mention something is missing, and there is a bloody dog's head.
Sputnik Mode - At the start of "Quarantine Zone" on Legendary difficulty turn directly around, and you should see a tunnel. Head down the tunnel and go straight until you exit it. Go straight across the open area, and you'll come across a broken pipe tunnel on your right. Straight in front of you is a small ledge running across the wall, above the green pit. Carefully get onto that small ledge and walk all the way to the end of the ledge to find the Sputnik skull. In this mode explosion force and melee force is greater.
The Face of Chris - On the map Containment, get a sniper rifle and go anywhere where you can see the part of the Halo in the sky that's closest to the Sun Base (the base with orange-yellow glowing buildings). Zoom in with the sniper on the part of the halo that's just below where it begins to get dark. In the clouds you should be able to see the face of Chris Carney (one of Bungie's developers) grinning happily.
Thunderstorm Mode - On the level "Cario Station" on legendary, make your way to the "Priority Shift" checkpoint. Progress until the room with mounted plasma turrets, right after the armory with the Elites. Clear out this room, and get on the raised area with the plasma turret that is on the side of the wall where the window curves. Look for two parallel beams on the ledge above. Climb up the supports for these beams and crouch jump up onto the upper ledge, then onto the beams themselves. Walk in the direction you came from and there will be a small ledge sticking out to the left, jump on it and pick up the Thunderstorm Skull from inside the trash container. This turns all Covenants into their spec ops rank.
Unnamed Skull - At the beginning of Armory, wait in the room until the Sarge starts telling you to get into the elevator. You MUST wait for him to say "Would it help if I said please?" When he says this, get into the elevator and go down to the tram. Get on the tram and face towards the INSIDE of the building. Press up against the glass doors towards the inside of the building. You should hold 'X' down, and you should pick up the skull. It's on a stack of green crates, near the end of the tram ride. Enemies will then target you over your allies (covenant or marine) and chase after you if you flee or take cover.
Weird Window Reflections on Headlong - In Headlong, grab a banshee and fly to the part of the level with water. On the same side as the Warthogs spawn, almost at the end of the level itself, there are some windows. Look closely at them, they aren't reflecting the other side of the level, but showing concept art for Halo 2. (A would-be human city at night)
Zanzibar Computer Screen - On Zanzibar, after you open the gate the computer screen (used to open the gate) changes. When you zoom in on the words you can read how to fix your computer and some other gags.
Big MC - This is a glitch only performable in the multiplayer level Burial Grounds. You have to have at least 2 people (At least one of them being a spartan) and a Wraith. Have one person (spartan) stand over the position where the Plasma Pistol (or other weapon according to weapon set) and make sure they are all the way up against the burning pillar. Have the other person get in the Wraith tank. Get the person in the Wraith tank to boost into the person in front of the pillar. If done correctly the person that was rammed will fall under the pillar. Then if you look up a giant sized MC in the colors of the rammed person will appear out of the sky. The weapons they were carrying will also appear occasionally.
Hold 3 Pistols - First Go to a level that you can get three pistols on, such as Outskirts. Go pick up a pistol. Then switch to your second weapon and pick up dual weapon, such as two SMG's. Go to another pistol and press X to pick it up. Now you have a pistol in you secondary and first slots. Now you can go pick up a third pistol and set it to your left hand (Press Y to do this). You can get up to 144 ammo: 96 ammo in the two and 49 in one.
Infinte Camo - After getting the envy skull go through a checkpoint while in active camo mode. To be safe use "reset to last checkpoint" so you can check if you did it right. Save and quit; then turn off the Xbox to remove the envy mode. When you reload your file you will find yourself with unlimited camo.
Skip Brute battle before the end boss - When you are flying around in the Banshee during the final level when you are giving support to your ally. You can skip directly to the final boss sequence if you are still in the Banshee after the door gets blown open. Fly to the right of the control centre building and aim towards the bottom right and if you fly close enough you should get a white screen indicating that you have started the cutscene. When it's over you will be at the final boss without fighting your way to him.
Unlimited Sword Ammo - You can do this in any two-part Campaign missions (i.e. Outskirts and Metropolis). If you finish the first level of the two-part mission with a sword with no ammo, you'll start the next level with a sword that has unlimited ammo. Though the sword doesn't show up when you arm it, it still makes all of the sound effects and acts exactly like a normal sword.