Browse Cheat Codes by Game Title
Video Game Cheats, Codes, Walk-Throughs, and Hints/Guides for Halo
| Platform: XBox
||User rating: 5
||Page visits: 971
Unlock New End MovieBeat the game on the Legendary setting to unlock a longer, different final movie.
Alternate ending sequenceSuccessfully 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 FlugsIn 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 GruntsWhen 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 JackelsUse 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 dropshipWhen 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 ringAt 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.
FireworksThrough 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 SeatWhen 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 GrenadesTo 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.
ShortcutPlay "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 bridgeAssault 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 GrenadeIf 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 BloodIn 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 GruntIn 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 legendaryHere'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 shortcutThis 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 TrickIn 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 CinematicThis 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 YetiThis 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.
Easy Flood and Covenant KillThis one works with all of the flood exept the little spider ones. Grab plasma weapons exept for the needlers. Shoot the plasma weapons at them and the flood will fall down and keep shooting them until there is blood all around them. For the covenant, shoot the plasma weapons at them. If you shoot elites, it only should take a few shots to wear down their energy shield with Plasma weapons, then shoot them 3 more times and they'll die. It should only take 2 shots at the most for grunts. The jackals have sheild but you can wear them down with plasma weapons and 2 shots to kill them. You have to switch excessively because the battery runs low. Finding plasma weapons shouldn't be a problem because the Flood and the Covenant carry them all throughout the game.
Defeating the Second LevelTo defeat the second level on Halo easily, the one where you have to kill all the aliens and rescue the survivors, kill the survivors instead. It's much easier and quicker then.
Kill The CaptainIf 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)
Glitch on the last levelThis isn't really a cheat just something to fool around with because i have gone through the game looking for fun errors (and found lots). On the last level (the maw, chapter: .....and the horse you road in on) i was messing about and found this, when you start the level your inside one of the escape pod bays (a small tunnel like thing), walk out of this one and to your left there should be another, walk in here and walk directly down the middle, look down and you should see a really big fall onto a cliff, walk as close to the middle of the tunnel as you can and then walk of the edge, you should fall bounce off a small hill and land still alive (try again if you died), you will now be stuck on this cliff and you can have a look at the ships outside and see how much detail the makers have really put into the game......have fun!!!!
Fewer Enemies on Assault on the Control RoomWhen yopu get to the first bridge on the assault on the control room, turnt to your left and Jump off (should only be done in 2 player cooperative). there will be a ledge. follow the ledge down until the end ofit. Kill one of the players. when the dead players screen goes "waiting to respawn" you then jump down onto the next ledge and try and slide off it. if you fail try again and again. so that the dead player respawns onto the next ledge than try and attemp to slide off the rock. than if succeeded go to the landing pelican. go upto it andf than press x. it will than take you to the scorpion tank. Use that of the warthog to go to the next door. when there get the banshee. and fly around and do what ever you want.
Flip The PelicanThis code can only be done on 2 players. At the beginning of the level: 343 Guilty Spark, have both players stay inside the Pelican by rapidly pressing the grenade button until both players throw the grenade. The Pelican will soon fly off with both players riding in it. Once the Pelican gets to the area with the 2 dimensional trees, have one of the players jump out. While the player that jumped out is falling, on his screen it will say: "press X to flip Pelican". Have the player that jumped out rapidly press the X button. If done correctly, the Pelican will miss the spot where it normally would land. Have the player that stayed in the Pelican get out as soon as it lands. Look on the player's screen that just got out of the Pelican. On his screen it will say: "press X to flip Pelican". Press the X button and the Pelican will flip over on it's top. Press the X button again and it will flip again and land normally. From here, you cannot flip over the Pelican anymore, however, you can melee it with your weapon and it will slide, just like any of the vehicles that you can drive. This glitch cannot be done on 1 player because if you jump out, the Pelican will disapear, and if you stay in, the Pelican will land safely and you will not be able to flip it over.
Flip The WraithThe Warthog and the Sniper Rifle is required to do this cheat. Move through the level: Assault On The Control Room until you get through the tunnel that slants up right after the part where it says "Rolling Thunder" at the bottom of the screen. Just ignore the Covenant Dropship that comes down and drops off some Covenant and two Ghosts. Quickly, get out of the Warthog and run to the top of the small hill that has a Gun Turret on it. Zoom in your Sniper Rifle twice and look to the left of the empty Wraith Tank sitting on the ice. You will see an Elite running for it. Quickly, kill him and then take out the rest of the Covenant so they do not destroy the Wraith on accident. Once all enemies are annihilated, get back in the Warthog and keep ramming one of the back corners on the Wraith. If done correctly, the Wraith will flip over. Then get out of the Warthog and walk up to the Wraith. On the screen it will say: "press X to flip Wraith". You can flip it over, however, you still cannot drive it. Explosives will not work to flip over the Wraith, as they would just destroy it.
Frozen MarinesOn 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.
Alternate Ending MovieBeat The Maw on legendary difficulty to see a new ending movie. The new movie will feature the Sarge and an Elite fighting over an Assault Rifle. Then, both of them will look towards the Pillar Of Autumn as it starts to blow up. The Sarge will then say to the Elite: "this is it baby, hold me". Then they will hug and the game will get back to it's original ending movie with the Chief flying off in the Longsword.
Magical FloodPlay 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.
Dime A DozenThis is more of a technique than a cheat. It helps you to kill elites. Heres how you do it: First, you need a plasma pistol and a human pistol. When you have those, use the plasma pistol first. Charge it up completely. Once charged, shoot the elite anywhere with the fully charged plasma bolt (taking off his shield). After that quickly take out your human pistol and shoot the elite in the head. Note, this will kill any elite instantly if done right. If you don't shoot his head, it only takes a few body shots.
Grunts: Any weapon.
Jackals: Human pistol.
Elites: Plasma weapons/assault rifle/sniper rifles/rocket launchers.
Hunters: Rocket launches/grenades/assault rifles.
Little dudes (parasites): Assault rifles.
Cadavers (body?s): Shotgun.
Exploding things: Nothing can stop them from exploding.
Can't kill FloodThis 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.
Higher JumpThis 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.
Hunter easy killHunters 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.
Playing one player two playerIf you are tiered of starting back checkpoints. Go to co-op and play one of the controlers this way you can run into a battle with no fear, because you will start right next to the second person every time.
Sneak in and KillIn some levels the covnet are sleeping or not paying attention. Simply pistol whip them. But, if you miss they will get up. You still have a chance to kill them. DON'T SHOOT THEM. Pistol whip them before they shoot.
Kill Fast on Split ScreenYou must make you own game in split screen. Then you turn off the sheild. And get a human pistol. When playing the game. Zoom in and shoot at there head if you hit him/her it kills them in one shot.
Cheap way to kill a freind on co-opYou 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.
Second BridgeOn 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.
More Power to Plasma PistolTo 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.
Slaughter your friendsWhen playing split screen make your own game with human weapons only. Then add all vehicles and get rid of shields. Go to any level with a good sniping position. Get a sniper rifle and go there as soon as you can. Because the shields are off 1 shot to any where but the arms and legs instantly kills them. It's cheap but really fun to piss off all your friends!
Really easy hunter killWhen your fighting a hunter all you need is a pistol and one shot.(and a brain so you can aim). get up close so that he charges. When he does dodge the attack in any way that gets you behind him. Now take your time and aim the shot right into the orange flesh of his back. Fire and he goes BOOM! This really helps in legendary!
Easy way to beat levelsPlay 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 ReconsiliationIn 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.
Grunts gone crazy!When you see large groups of grunts and jackalls you usually don't need to use grenades because they're so damn weak but in legendary every cheat helps. Throw a plasma grenade and stick it to one of the low ranking grunts(yellow or red bio suits not so much on the silver ones) The grunt screams and runs to the big group of guys screaming "GET IT OFF! GET IT OFF!" then he blows up and kills the rest with him.
Messed up GunIn 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.
Friendly MonitorIn 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.
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.
Plan B shortcutOn 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.
Easier Way To Kill HuntersWhen 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.
Lower Difficulty Level In GameIn 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.
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.
Unlimited Ammo for Co-op ModeWhen playing cooperative mode in Halo and your running low on ammo for your assualt rifle, pick a spot that is clear of any ammo you dont want, and have your partner hit you in the back of the head. All of your weapons will drop where you fall and you will come back with another assault rifle and an alien pistol. Just walk over your weapons you had and your assault rifle will have 120 bullets more than you previously had. You and your partner can do this if your running low on health as well, as long as one of you are alive when it happens.
Ultra Team WorkIn co-op mode,if there is a ledge to high to get to have one player stand right up to it and the other jump on top of them to get up.This is really fun,but beware,if the bottum person is killed the top person may be also.I'm not sure why,maybe just a glitch on mine.
Quick-sand ElevatorOn an elevator in any building built by the forerunners (i.e. Assault on the Control Room) walk backwards into the control panel. You will start to kind of go up and down furiously before going strait through the panel.
When this happens, immediately walk forward, towards the lift. If all goes well, you?ll sink halfway through the platform and be stuck. You can still look, aim, and shoot. You may have to try it a couple of times.
It?s more fun when you play with a friend because you can activate the lift and see your legs flailing around from under the platform.
Pretend to Fly a PelicanOn the Silent Cartographer level, after you unlock the door that leads to the map room, you will hear a call for help from a pelican under attack and inevitably crashes, leaving you a rocket launcher. The pelican crashes next to a butte with jackals on top. Drive a warthog on the catwalk (on the ocean side) that leads to the top, and drop down on the pelican. While still in the car, wedge yourself in the space between the cliff and the pelican until your practically sideways (with the tires facing the rock). Jump out, and you?ll be inside the pelican?s cockpit with an inside view of the control panel and all of the little details Bungie put in there.
Armless FloodOkay, this one isn't really code, but I've done it tons of times and its pretty funny. Wherever you have flood to fight, take out an assault rifle and shoot only at the arms of the corpses, this blows them off without killing the corps completely. After that the thing keeps running at you, but stopping two feet away because it can't do anything. As long as you don't kill it, it'll be your shadow.
A Window of OpportunityAbout halfway through the Maw, you need to traverse through maintenance corridors, you will emerge into a battle between the Covenant, Flood, and the Monitor?s drones. When you see the door out, go right to find a blood-stained health pack, go left and you will come to another door leading into a section closed off by blast-doors with ammo and a bunch of fiery rubble.
Once inside the room, you can shoot through the would-be bullet proof windows in the blast-door with any human weapon except the rocket. This is a great way to get rid of the Covenant and drones because the AI isn?t supposed to realize that they can shoot back. The flood never stop coming at this part, so don?t waste your ammo.
Truth and Reconciliation glitchAt the end of the Truth and Reconciliation, when you get to the docking bay with Captain Keyes you will meet a whole slew of Covenant waiting for you. Go strait to the controll panel-that you would normally hit when the battle was over-and hit "X". Then fight normally.
If that reckless Keyes gets killed, it will show his corpse, then go to the cut-scene of you activating the control panel, then the screen goes white, and you go strait to the next level.
You can also kill Keyes yourself just to end the level early.
Formation DWhen there is any high place such as a butte or hill, one player stays back with a pistol or sniper, while the other player heads in with another weapon of his/her choice.
Formation CWhen there are too many enemies to take on at once, or when stealth is the key, both players stay back and snipe with a pistol or sniper rifle. This works best when there are places to hide behind such as in "Truth and Reconciliation."
Formation BWhen there are not many enemies near, both players charge in and attack. NOTE: This can also be used as an S.O.S formation combined with other tactics (preferrably Formation D).
Formation AFor multiplayer coop mode, formations can be very helpful. In formation A, player one stays a little while back with a pistol or sniper and protects player two, while player two moves in with another weapon of choice (preferably human or covenant rifle). Then, player two pulls out a pistol or sniper and hides behind something while protecting player one, who then pulls out his/her weapon of choice and moves toward the enemy lines a little (of course, whoever has out their weapon of choice is also shooting the enemy). Cotinue this process for as long as need be for the time. This process can also be used for more then two players.