Unlock New End Movie
Beat the game on the Legendary setting to unlock a longer, different final movie.

Alternate ending sequence
Successfully complete the last level of the game in campaign mode under the 
legendary difficulty setting. The new ending features a human and alien fighting 
hand to hand. The human will say "Its over", and then they hug because they 
know the explosion will kill them both.

Defeating Flugs
In the later levels of the game you will encounter new enemies called Flugs. These 
enemies will be small at first, but they will attack and control anything alive. Use a 
shotgun on these baby Flug as they tend to group in large numbers. By using the 
shotgun it will send a storm of bullets and kill most of them that are around. Use a 
shotgun on the possessed Flug, and it will kill most of them in one shot. This is 
made easier by the fact that most of them carry shotguns.

Defeating Grunts
When the Grunts are sleeping you can beat them to death with the butt of your 
gun without waking up any of the other Grunts. You can usually kill a four to seven 
of them before an alien spots you. They start sleeping in level 5, Assault on the 
Control Room. Just remember not to shoot or they will wake up.

Defeating Jackels
Use a photon weapon to destroy a Jackel's shield quickly. When you encounter a 
Jackel, run up and hit it with your weapon or get out a gun that uses bullets, not 
energy.

Covenant dropship
When Covenant dropship is getting ready to unload a group of Covenants, throw a 
grenade into the door as it opens. The blast will kill several of the enemies since 
they are all in one area.

Assault On The Control Room: Spinning ring
At the Halo start up screen, choose multiplayer mode. Choose cooperative play at 
the next screen, then choose your profiles at the next. Choose the level where in 
the beginning it says, "I would have been your daddy" (Assault On The Control 
Room). On the difficulty screen, choose legendary. When the level starts after the 
introduction sequence, have one of the players quickly press X when the "Press X 
to get on the Pelican" message appears. That player will re-board the ship and 
start flying with it down the hole. The other player will quickly die because of the 
aliens, and will be respawned on the spinning ring. Make sure to jump where there 
are gaps. If you are good enough, you can even jump to a nearby ledge. 
Additionally, once you are respawned on the ring, quickly jump off and fall to your 
death. Sometimes you will be respawned on the lowest ledge in all the blue haze, 
and a "Press X to flip the Pelican" will appear that the top of the screen very briefly.

Unlock New Guns
To unlock two new guns, first beat the game on the easiest setting (Easy), and 
then on the hardest setting (Legendary) in under 3 hours.

Fireworks
Through one plasma grenade in a wide open spot, then stick another directly on 
top of it if you do this fast enough the first gernade will launch the second and 
vuaola fireworks.

Your in My Seat
When one of your computer controlled buddies is in a vehicle spot/seat you want 
simply go over to that spot and press X. They will graciously move.

Infinite Grenades
To get infinite grenades, scorpion, and ghost in multiplayer- Go to the multiplayer 
screen: go to edit game types: In that menu you will have the option to make up 
your own game type.

Shortcut
Play "Assault on the Control Room". It doesn't matter what difficulty setting or if 
you are playing 1 or 2 player mode. Get to "If I only had a super weapon". Rush 
right ahead and ignore the Jackals and the first Elite. Instead, kill the second one 
as he is somind over the hill. Then run to the next one who is coming around the 
banshee. If you kill them both, the two banshees will be yours for the taking. I 
would suggest using the Plasma Rifle for killing them, as it stuns. You can use the 
2 banshees for a banshee fight with a friend, too. Anyways. Ignore the enemies 
and do not go to the end of the bridge. Instead, go to the top of the hill that leads 
to the Control Room. There will be no Hunters, or aliens on the way up the hill! 
There will be the enemies that come out of the big door, though, but this shave's 
precious time off the level.

How to get a Banshee sooner than the bridge
Assault on the control room: How to get a Banshee sooner than the bridge, 1 
player. 

Fight your way through the level to the first snowy open area, kill the enemy tank 
and all the rest of your enemies then hop into the Warthog. Make sure you get the 
Rocket Launcher and the Sniper Rifle. The next open area has a battle raging and 
an empty Scorpion, hop into the Scorpion and waste all the Covenant with the 
cannon. To the left is tunnel, to the right is the obvious way to the next open area, 
go to the right and clear the enemies around the corner. Stop (If you kill all the 
enemies in the next open area an Elite will get the Banshee before you do and use 
it to attack you. You'll know you're in the right place if there's another enemy tank 
in the area.) Now, jump out of the Scorpion and stay to the Left edge of the valley. 
Look up, you should see a Ledge above you with some lights on the underside. 
The Banshee is on that ledge so get underneath it and shoot some rockets up to 
knock it off. Remember to move something forward with concussion weapons you 
have to shoot behind it, so use you brain. If done correctly off will tumble the 
Banshee, if done incorrectly it will be pushed farther in. As an added bonus the last 
few sections of the level will have no enemies due to the fact you've skipped so 
much.

Plasma Grenade
If your going to use a plasma grenade, try throwing the grenade on the alien 
where it sticks onto them. It will blow up on them making sure it will kill the alien. 
Also the aliens can do this to you if you don't move.

Name in Blood
In the very last level of the game, as you're driving the Warthog out of the Pillar of 
Autumn, on the second jump, do not go all the way across. Then back into the 
room thats behind you and get out. if you look on the wall the name REX will be in 
blood on the wall.

Hungry Grunt
In the very last level of the game, as you're driving the Warthog out of the Pillar of 
Autumn, get out at the 2 tunnel off of the main one and there will be a grunt at the 
end of it. he should say something like " I can't wait to get back to the ship and eat 
some grub!"

Good tactic for legendary
Here's a good way of killing elites or hunters in legendary. get a needler and some 
ammo and just unload it on an elite and watch the show --NOTE-- You have to get 
in close enough for the needles to find their mark, and the delay until they explode 
leaves you wide open for their plasma rifle, so bring a backup weapon. 

For the hunters, unload an entire clip at their backs so the shot doesn't reflect off 
their shield and start shooting at them with another weapon while waiting for the 
needles to explode (or just sneak up on one and smack him in the back, and if you 
cant to that...a well placed plasma grenade to the head should weaken it, but it will 
most likely just piss it off.)

Silent Level shortcut
This will help if your annoyed by always having to go back because the yellow 
dude locks the door. First find a warthhog and get some people inside. Go where 
the place where there are lots of guys and where kortana says the covenant are 
putting up a real fight. Go down completely with your warthhog and go at full 
speed directly where the yellow dude is. If you did it right then your warthhog will 
be half way through. Press forward and get out. Then pass the level like you 
usually do and come back where the warthog is stuck. You may think it is 
impossible to get out but just press back and then get out. You will be in back of it 
and now you're done the hard part!

Elite Kill Trick
In the levels where you must face the Covenant there are certain aliens called 
Elites. They are the big ones which are usually blue, red, or sometimes yellow. If 
you have a gun with a scope ie; pistol or sniper rifle,try to get behind an elite 
without being seen by it. Next, Zoom in at the back of it, you will see yellow spots 
on his back or his head. If you shoot them a yellow liquid sprays out and they die 
instantly. This cheat helps because you only need to use 1 bullet and you do not 
have to get in close to kill it. It also looks cool when the yellow stuff sprays out.

Kill Master Chief in Cinematic
This is only possible to do in co-op mode, so get a friend to help out. 

Near the end of "Assault on the Control Room", at the base of the big pyramid-
type building, rush over and steal a Ghost from the two parked ones. 

Get the Ghost (in one piece) to the top of the pyramid (Get your friend to do the 
fighting while you take care of the Ghost). Open the large blast doors, kill 
whatever is in your way, and keep going down the hallway. 

When you reach the VERY LAST door (ie. The one that triggers the cinematic), 
stop. Line the Ghost up with the centre of the door as best as you can, and back it 
up about one or two Ghost-lengths away. Have your friend hit the switch to open 
the door, wait a half-second or so, and then gun it towards the door. 

If your timing was right, the Ghost should JUST fit between the doors, and during 
the cinematic the Ghost (now without a pilot) will mow down Master Chief from 
behind, killing him. The cinematic will go on as normal, except for the absence of 
Master Chief (you will still hear his voice, though). Also, in certain camera angles, 
you will see Master Chief's corpse in different poses, such as tilting 45 degrees to 
the left with his gun stuck in the ground. 

It will work more than once (I've done it three times so far), and it just looks 
damn funny to see Master Chief get run down by his own Ghost. Props to The 
Fiend for co-piloting.

The Yeti
This isn't so much a code. It's just something that shouldn't be where it is. In the 
level "Guilty Spark 343", there is a crashed Covenant dropship just around one of 
the corners you must turn (the second or third, I believe). Up above this dropship 
is a tree jutting out over a ledge. On this object is a Flood-infested Elite (the 
bulkier Flood ones that don't pop). It appears as you come around the corner and 
runs back along the log after a few seconds then disappears. It is named 'The Yeti' 
because it diappears whenever seen. This is really weird because the Flood have 
yet to be introduced at this point. Also, the Yeti is invincible. You can sneak up on 
it from behind (which is too long and tedious a subject to go into), but don't have 
your co-op partner go around the partner until you're in position. It can withstand 
a pistol whip to the back of the head and a plasma grednade, so we just gave up. 
It's really fun, though. I suggest you try it.

Faster reloading
To reload most weapons faster, press X, then shortly after that 
press B to melee. Note: For the shotgun this will cause you to stop 
reloading all together.
  
Extra shotgun ammunition
Take a shotgun that has 12 shots and 0 clips. After you shoot it 
a few times, you should be able to reload manually. You can do this 
about ten to twenty times.
 
Faster Warthog weapon use
This trick works best in multi-player mode. Drive the warthog in 
a straight line. When you see an enemy, jump out of the Warthog. 
Tap X repeatedly and sidestep to the right. If you are quick enough, 
you will exit the Warthog and jump on the LAAG gun without stopping, 
while the Warthog slows down. This also works well on ice, because 
you keep sliding.
  
  
Defeating Flood types
Do not try to take out any Flood types with a sniper rifle. It will 
simply go through their bodies without killing them. The weapon 
of choice is the shotgun. You can take them down with one shot. 
Remember, the closer they are, the faster they fall. On the small 
crawling Flood, use your assault rifle in short controlled bursts. 
Once one pops, it will also pop the ones nearby. Save shotgun and 
pistol ammunition for the working class Flood to drop them fast. 
It is also a good idea to hit them with your gun after they fall 
to make sure they are dead. On the fat Flood, use the shotgun to 
pop them, then clean up with rifle. When you first meet the Flood, 
they will outnumber you in groups. For the large Flood, use a shotgun, 
rocket launcher, or most importantly, a fragmentation grenade. Do 
not use a plasma grenade because they will run towards you and kill 
you. When you get attacked by the Flood, after you make them fall 
down the first time, shoot their head off while they are on the 
ground. They will not get back up.

Defeating Hunters
Normally Hunters are the hardest Covenant to kill, due to their 
powerful armor and shields. However, even the strongest armor has 
weak spots. If you look at their necks or backs, you can see an 
orange spot. Aim for it. One shot with any gun will kill them if 
you hit them there. The best way to kill a hunter is to use a sniper 
rifle to zoom in on the orange spot. If you are being chased by 
a Hunter or an alien with a sword, run backwards while facing the 
alien. Jump when they try to slash you. Throw a plasma grenade at 
the alien and it will stick to him. Turn around and run in a zig-zag 
pattern to make sure he does not catch you in the explosion. If 
you are playing cooperative multi-player mode, have player two run 
in front of the Hunter until his back is turned to player one. While 
the Hunter is trying to turn player two into mush, have player one 
run up to the Hunter's back and melee attack the orange spot. The 
Hunter should die with one hit. You can kill the Hunters in a head-on 
assault. Get in close and use the pistol or shotgun. Aim for the 
head holding down the trigger. Your first shot(s) will knock back 
the head, exposing the unarmored neck. One shot in the neck and 
they will die.

Hunter easy kill
Hunters are actually pretty easy to kill, the trick is to be in close combat. Just jump 
to the side when they try to hit you and shoot them in the back. They have no 
armor on their back so 5-10 shots with the pistol takes them out pretty easy.

Higher Jump
This is not much of a cheat rather then something I discovered. You have to do 
this in co-op mode. First go to any level if one of you dies (this has to be done in a 
building) back up into a corner and sometimes that person will be reborn on your 
thus making that person able to jump higher.

Can't kill Flood
This isn't a cheat but it can be annoying. If you have a sniper rifle and you use the 
shot on a Flood the shot will go right through it which is just plain weird.

More Power to Plasma Pistol
To do this you must have a plasma pistol, when you do hold down the trigger until 
the gun is shaking rapidly. That makes it more powerfull.

Second Bridge
On the second level when you are getting out of the ship. To your left there is a 
bridge and below it is another. Go to the right of it and there should be a crack. 
Slide down it slowly. It is just for fun.

Cheap way to kill a freind on co-op
You must do this on co-op. When you get in a Banche fly around and kill your 
partner. When he/she is dead. Fly into a wall or tree if done right your partner will 
fall to his/her death. it is pertty mean but fun.

Magical Flood

Play through the level: Two Betrayls, until you get to the part where it says: "Final 
run" at the bottom of the screen. Instead of going straight forward to the battle 
where the Flood and the Covenant are fighting, look to the left and you will see a 
small hill with a large tree and a few small rocks to the left of it. Go towards the 
hill and jump over the rocks and go to the left of the tree that will be right in front 
of you. Ahead you will see a small tunnel. Get close enough to the tunnel that you 
are inside it a little. If done correctly, Flood will appear out of nowhere and attack 
you. This is suicide, because some of the Flood members that appear have Rocket 
Launchers.

Frozen Marines

On the level: Assault On The Control Room, take any vehicle and move through 
the level until you get to the part where at the bottom of the screen it 
says: "Rolling Thunder". Instead of going forward and look back at the Marines (if 
you helped them survive through the level until this part) that were chasing after 
you on foot. They will be frozen in running position. This happens because you 
took a vehicle through the checkpoint. I recommend not killing them, because if 
you go through the level normally and come back, they will be unfrozen.

Kill The Captain

If you are in a happy and silly mood try this: at the first level when the captain 
gives you a pistol, get out of the room to the place where you see the first grunts. 
kill them and go back to the captain's room and kill him. Its so funny. Cortana will 
say, " WHAT THE HELL ARE YOU DOING? Security to the bridge. The master chief 
has gone crazy". Then you will get locked inside and the troops get invincible and 
come and attack you because they think you are a traitor. (if you are playing 2 
player mode and one of you kills the captain, the other player poofs to the 
captain's room and gets locked too)

Easy way to beat levels:
Play levels your stuck on in co-op and have one player always hang back in a safe 
place. This way the other player keeps charging in and killing things. Because one 
player is far back you'll be able to respawn unlimited times and take out large 
armies bit by bit.

Beat the Truth and Reconsiliation:
In the very begging I sugest you use 3 main snipe points. 1st is at the top of the 
hill near the pelicans landing spot. You'll see two rocks jutting up and one 
inbetween them. You can duck behin it then waste everyone insight. Next is a rock 
closer to the edge of the hill if you go forward. Then finally go behind the large 
wall like thing and come out to waste the rest of them.

Clear Alien Drop Parties :
When facing a drop ship, aim at the hatch that the enemies will come out of while 
the ship is descending. Your crosshair will turn red when you target an enemy 
(inside the dropship). This means you can shoot the enemies in the ship while it is 
still trying to land. You can get rid of a lot of enemies before the dropship deposits 
its soldiers, making the fight easier later on! 

Easter Egg: Rex 
On the last level the Maw, on the last checkpoint, when you go off the big jump 
onto the small bridge, drive the warthog so a quarter of it is off the bridge. Jump 
on top of the warthog and jump on top of the wall on either side (the one closest to 
you) and follow it up to an upper, smaller bridge. There are two hall ways and go 
in the one with blood in it. Look to the right and you will find the name Rex written 
in blood. 

Accurate Assault Rifle 
When playing with the Assault Rifle, the most accurate way to kill a enemy is with 
the three-round burst. To do this, just repeaditly tap the fire button. It should give 
a series of short blasts that come in handy when low on ammo, and offer more 
accurracy compared to just holding the fire trigger. 

Always Have Ghost in Assault on the Control Room 
Right after you have to abondon the tank, take a Ghost and go next to the door 
that you need to in order to finish the level. You'll find that the door won't open 
while on the Ghost, so get off your Ghost and the door will open. Before it closes 
again, get back on your Ghost and go through. 

Falling without losing life :
When falling from high distances your shield or is depleted when you hit the 
ground. If you hold the crouch button shortly before you hit the ground, you will 
not be affected in any way. This is very helpful when playing in multiplayer on 
levels like Hang 'em High or Prisoner. It has to be timed right though.  

More Guns On The Pillar of Autumn :
On the level "The Pillar of Autumn" on Easy difficulty, get to Captain Keyes as 
quickly as possible. When he hands you his pistol run out to the bridge and down 
the corridor where you load the pistol. If the glitch is done correctly, you shouldn't 
load the pistol, and the 3 Grunts shouldn't be at the end of the corridor. 

Continue and pick up the Assault Rifle from the dead marine's body lying in the 
doorway then kill the Elites and Grunts and pick up a Plasma Pistol or Plasma Rifle. 
Go back to the corridor where you were supposed to load the pistol and keep back-
tracking. Eventually, you should load the pistol and the 3 Grunts at the end of the 
corridor should appear. You will now have the pistol, the Assault Rifle and the 
Plasma Pistol/Rifle. 

On Top Of The World 
On the Silent Cartographer level, go anywhere where there is an overshield, and 
bring a warthog with you. It's best to do this in co-op because it's easier to collect 
the grenades and "initiate launch-off". Get as many grenades as you can, and 
have your partner kill you, and vice-versa to get the grenades into one big pile. 
(Make sure this is *near* an overshield.) Drive the warthog onto the grenades and 
try to position it to where it would fly up on top of the level. Before you do 
anything else, make sure you get a checkpoint. Have your buddy pick up a 
grenade and toss it under the warthog, and RIGHT as he throws it, pick up the 
overshield and get into the warthog quick. If you get into the warthog while the 
overshield is charging, you should get blasted upward unharmed. You should reach 
the top of the level. If not, reposition the warthog, or get more grenades. When 
you're up there, kill your friend with the plasma pistol from long range, and he 
should appear up there with you. Have fun! 

One Hit Elite Death 
Have you ever wondered if it is possible to kill an Elite easily? When you come to 
an Elite pacing around the room, time how fast he paces by hiding behind a shield 
or a glass window, stay at a safe distance, or just hide behind a corner. Once you 
are sure you know when he will turn around, run up behind him and use the melee 
attack to bash the Elite on the back, instantly klling him (note that if you did not do 
it correctly, it will turn around and attack you). This comes in handy alot on "Attack 
on the Control Room" and on Legendary Difficulty. 

More than one "Yeti":
On the level 343Guilty Spark, go through the level normally. When you get to the 
wooden bridge where there are a couple of Jakals, kill them, but don't go onto the 
bridge until you do. After you kill all of them, go onto the bridge. As described in 
the "Yeti" cheat, if you look to your right, you will see two Flood. But if you don't 
look to your right and hurry across the bridge instead, straight ahead next to a 
bush up on a hill, a Flood will run out from the bush and run down the other side of 
the hill. Once you see it, watch it run away and immediatley pause the game. Click 
on "Revert to Saved". Then you should start back at a checkpoint after you killed 
the Jackals, but before you ran onto the bridge. Run accross the bridge, but keep 
an eye on your radar. As soon as you see allies on it, quickly jump off the left side 
of the bridge. You may loose some of your shield, but who cares!? After you jump 
off the bridge, run straight ahead. If you go fast enough, you should see a Flood 
run in between a couple trees and a bush. Keep going and pass through the trees. 
If you timed it correctly, just as you pass the trees, a Flood will run a few feet in 
front of you. You can try shooting it, but as soon as you kill it, it gets back up and 
becomes invincible. Then it runs forward, and disappears.

Friendly Monitor:
In Halo, I was trying to do another cheat and it didnt work but i found something 
else: On the last level (the Maw), you start out in a life pod launching area. It is 
tunnel like and small. Walk out of it and turn to your left into the other life pod 
launch area. After, go back into the area where you start out in and look out of the 
edge. You will see the monitor's machines that shoot orange lasers at you come up 
(and their wings are closed ) and they will come into the launch pad where you are 
but they wont shoot. You can either watch them fly by you or blow them up 
because they are defenseless. Note: They will turn around and shoot you when 
they get to the end of the tunnel.

Messed up Gun:
In the level assault on the control room you can get your sniper rifle to have an 
assault rifle body. When you have a sniper rifle go through a checkpoint. Then you 
switch it for an assault rifle and as it switching save and quit. If done properly 
you'll be able to use a sniper only it will have the body of an assault rifle and beats 
like an assault rifle.

Plan B shortcut:
On the level Assault on the control room,where it says "if i only had a super 
weapon", there are two ways to skip part of the level. The first way is to try and 
get the banshees using the Sortcut technique. The second way is to fall onto the 
pirimid structure that slopes from the end of the level down. It is best to have full 
shields while attempting this trick so you don't die. You must aim yourself in the 
middle of the structure as best as you can. Fall, do not jump, onto the sructure. 
Right before you hit, crouch to prevent damage. Follow the structure to the bottom 
into a pit. The pit should contain a rocket launcher and a sniper rifle if you choose 
to use them. Continue to the top of the structure on foot or with a bonus. The end 
of the level will still have no enemies. It is harder to do this than it is to get the 
banshees, that is why it is plan B.

Dead Man Walking...:
On the first level, when you meet the captain and he gives you a pistol, go up to 
the point where you have ammo for your pistol. As soon as you have ammo for it, 
turn around and go back to the captain. Kill him with your pistol and then you will 
here Cortana say "What the hell do you think you are doing?! Attention Marines, 
the Master Chief has gone rampant, let's bring him down boys." Then, swarms of 
marines will come after you trying to kill you. You can use this to practise your 
skills if you wish as no matter how many marines you kill, they just keep coming.

Lower Difficulty Level In Game:
In order to lower the difficulty level form legendary to heroic, heroic to normal, 
and normal to easy while playing, hold down back, then press left and right trigers 
at the same time, then press Y-A-X-B. All of this must be done VERY QUICKLY. No 
message will appear to show that the cheat has worked, but you will notice that 
the game is a lot easier.

Easier Way To Kill Hunters:
When you run into a hunter, pull out the human pistol. As it charges at you, it will 
lift its gun arm, revieling a spot of orange flesh. Shoot there. This Also works in 
the centre of the back and in the back and side of the neck. All these places will 
kill the hunter in one shot.