Note:-  This game is also known as Halo

Beating the flood easy:

Shotguns, pistols, and assault rifles and plasma guns and grenades work the best for the flood.
Sent in by: krazykid9333

On the third level where you save the captain, don't go into the prison room he is in, first go to the other prison room and get the camouflage from behind the "holo-panel" then go past the two jakels in the corridor and go to the captains prison room, walk up and stick a plasma grenade onto the golden elite with the plasma sword, then as quick as you can hit the switch to open the prison doors, then at the right moment walk up to the opened door. The cut scene should start and while the captain is talking the marines will get shot down one by one, near the end you will die, he keeps talking to you when your dead, then when the cut scene is over you and all the marines will be fine. I did this on heroic so it might only work on that.
Sent in by: armadilloa16@hotmail.com | Please send any questions although i don't know to much.

Warthog drives straight up Mountain- In level "HALO" after you beat the initial battles with covenant and enter the underground cave you will exit and begin the "Reunion Tour". If you follow the path to the left just over the river and go all the way to the last entrance near the cliff and waterfall go into that last entrance. I would recommend battling the covenant first with a sniper rifle just as you are at the top of the entrance on the hill. After you have destroyed all covenant get in your Warthog and go back toward the entrance where you came in. Before you leave look just to your right and up the mountain. There will be a huge patch of green on the mountain and it looks sort of slanted. Get in your warthog and drive towards it. It looks impossible to drive up but once you start the Warthog will slowly climb its way straight up the mountain. Once you get to the top you have a view of almost all of Halo. If you have any questions email at jakepachuco@hotmail.com
Sent in by: jakepachuco@hotmail.com

Secret Piano Song - At the beginning of "Assault on the control room" just as the ship is dropping you off press X and jump back on the ship and ride it down below. Eventually you will be thrown out of the ship as you enter a hazy mist. Just as you are about to fall off press X and jump and you should land on a hard surface ledge unharmed. You might have to do this a few times to get it right. As you are on the hard surface ledge walk around until you hear music. You should hear a sad piano song playing which sounds really neat! But it will only work if you are standing in the right spot.
Sent in by: jakepachuco@hotmail.com

Easy Banshee kill - Wait until a Banshee is directly above you, then shoot it in the belly with your shotgun. On the easy difficulty setting, it will explode with one shot. Moving forward when you do this can keep the wreckage from falling on you.

======##*!Get FirE WoRkS!*##======
Well first go to multiplayer or 1 player mode and then go to any level and then get 2 plasma grenades and then throw the plasma grenades on top of the other one and then watch the sky and they will launch up in the sky and explode!
Send in by burgundy

Here is a good tip for the 'Keyes' level (after the flood is released). When you find the captain, after the cut scene, the flood quickly rushes in. Go to the door, and the covenant will enter and start fighting the flood. Quickly make your way to the spot under the control room platform. You can even duck underneath the platform for a great sniping spot. The covenant will be defeated by the flood, but you will be able to pick of the remainder with ease. The flood aren't smart enough to duck and shoot you. You can snipe them at your leisure, just watch out for the few that find your spot.

This is a great trick for the level where you need to destroy the second generator. Take the ghost that you have and fly full tilt past the flood and the covenant. Don't worry about the tanks, fly until you reach the banshee's. exit the ghost, get in the banshee, and fly. If you did this properly, you are airborne with little damage to you and the banshee. If the banshee did get damaged, there is spare waiting on the ground. Now that you have the banshee, just pick off all your enemies below. Take out the shade (AA gun first, tanks, second.)

The best weapon against the flood is the shotgun. The best long-range weapon (excluding rocket launcher) is the needler.
If you lock on to an enemy (sight turns red) and fire a full clip...boom. (best used on covenant). An easy way to kill the flood, is to shoot (with rife, or plasma weapon) the big brainy guys, and for the little ones...just butt end em with your weapon this saves ammo, and if you get hit just recharge.
Send in by CyC

My friend that comes over every Saturday, plays level 4 with me blowing the warthog so high that you can't even see it. Here is how to do so. When you killed all the aliens at the beginning by not using any grenades, put the warthog anywhere, (if you want and trying for the first time try getting it over the gray bar at the beginning of the level) Then stand behind the warthog and get your partner to kill you so that the grenades go right under it. Then do that to your partner, and find more grenades. For more fragment grenades that make it fly higher, kill all your people. Once you found more, kill each other again, and make sure you have ONE grenade to set it off and KWABOOOM! WARNING don't stand close, last time my friend died, so the next time, he moved farther back and I accidentally threw the grenade beside the car instead of on the pile of grenades and the car flew sideways and killed him. (Take cover) If any questions, email me.
Sent- in by: talismans51406@hotmail.com

An easy way of passing everyone to get the last banshee on level 8, is using a ghost. People would think of it, and try to get up, couldn't and give up. So just get speed, and ram off the wall, then drive to the banshee really fast.
Sent in by: talismans51406@hotmail.com

Another impossible but fun thing to do is on the third level. When more marines come on the purple warp from the dropship, kill them all, go on the warp, and when you are in the ship, your people are come back alive and mad. 
Sent in by: talismans51406@hotmail.com

To skip half the level on The Silent Cartographer, take the warthog in the building where the covenant first close the door on you. This is hard to do, but possible, (Done it twice out of all the times I played) ram the warthog through the door before they close it. Sometime the car will get stuck and sometimes it will go all the way through. When your going down to pull the switch, Cortana starts saying, "They closed the door on us and we don't have enough firepower to get through it," when you are already about to get the last switch. If any questions, e-mail me.
Sent in by: talismans51406@hotmail.com

To unlock new guns, like the flamethrower, plasma sword, chain gun, and a sniper that zooms in 5x, you have to beat the game in normal settings then legendary settings in under three hours.
Sent in by: talismans51406@hotmail.com

On the fourth level, you can kill the yellow covenant with the plasma sword behind the door that they close on you two different ways. The first way you need an assault rifle and a partner to crouch on. All you have to do is shoot through the little window on the door and kill him. If  you have no partner, just jump up and down. The second way is leaving a warthog in front of the closed door full of marines. Then when you pull the switch to open the door, your marines will kill him. There is something awesome that happened to me which MIGHT not happen to you but if  your lucky there might be two copies of the yellow covenant. If you have any questions, e-mail me.
Sent in by: talismans51406@hotmail.com

One shot kill with the hunters with one sniper bullet or one pistol bullet. All you have to do is shoot them in the back in the orange area. It can be done one shot in any difficulty. It is alot better if your invisible and shoot him in the back or if you have a partner to distract him.
Sent in by: talismans51406@hotmail.com

On the fifth level, you can get a really early banshee which is really cheap because you can go past the whole level with nothing, enemies, nor supplies will be loaded. Okay here is how. When you get the tank, destroy everything in your sight that is bothering you then take the tank underneath this flashing platform, which you will find if you follow the bad guys, (NOT THE CAVE). Now get out and make sure you have a rocket launcher and sniper. If you have neither then go back to where you first got the tank and where the ship crashed is rocket launchers and for the sniper, kill one of your guys for it. Now when your all set, then zoom in with your sniper under the flashing platform, aim, then take your rocket launcher out and shoot right in the middle and a banshee will fall down. This may take a few shots, so don't give up. This is awesome in legendary mode.
Sent in by: talismans51406@hotmail.com

For an alternate ending sequence, beat the game in legendary setting.
Sent in by: talismans51406@hotmail.com

For a different speech from the captain in the first level, do it in legendary setting. In the easy-heroic speech he is pretty calm. In the legendary speech, he is aggressive. If you have any questions then e-mail me
Sent in by: talismans51406@hotmail.com

Something impossible, but fun to do in the first level on any difficulty settings is to kill the captain, one of the drivers or a worker on the sides. Then about eight people that can not die will come at you shooting with infinite bullets. The doors will also be locked, so you can not 
make it out alive.
Sent in by: talismans51406@hotmail.com

Hidden Song:
Okay- first, what you need to do is start playing the level "Assault on the Control Room," on any difficulty (if it doesn't work, play it on the EASY difficulty). Then, you need to play through the level until you reach near the end, where you have a chance to get two Banshees. Snatch one Banshee (all you have to do is run right towards the one closest to you and get in it before the elite does). Now that you have a Banshee, fly towards the enormous structure to your left. If you haven't already noticed, there is a large pillar that goes through the middle of the structure. Near the top are two things that wrap around the pillar between two blue lines. If you don't know what I'm talking about, the're the things that have a space between them and the pillar, both large enough to fly through. Fly up to the second to the last one, land on it as best you can, and get out of the Banshee, so that you are now standing on the thing. If the Banshee hasn't fallen off of the thing yet, knock it off, either with a grenade or several melee attacks. Watch the Banshee as it falls off of the thing and down to the ground (watch it until it hits the ground). Now, you should be stranded on the thing, with no way of getting down. Facing the pillar, walk to your right along the thing until you reach the blue line (don't step off of the thing whatsoever, or the music won't play!). NOW, wait a few seconds, and a sad piano tune should start playing. If the song doesn't play after a while, try the process over again (go back to the last checkpoint), and this time use a pistol to zoom in on the Banshee as it falls off the thing. It may take a few times to do right, but the song is pretty cool.
Sent in by: Doug S

On the fifth level, you can skip quite a lot on that one spot where you cross this snow bridge with the two banshees that fly off right in front of your eyes. To do so, you can either run as fast as you can to the first banshee and take off with it to the left side at the end of the level or if you cant seem to get in the banshee before the tall red guy takes it then you can just go to the rock right outside the door and jump off. If you land close to the side then you can break your fall. Read further if you didn't get the banshee and just fell off the side. When you landed safely then you can if you want, get a sniper and rocket launcher down in a crack under this slanted grey thing. The rocket launcher is good for blowing up the thing that shoots blue crap. It's a purple alien vehicle which i call that. Anyways, if you have any questions or anything else, e-mail me at talismans51406@hotmail.com.
Sent in by: talismans51406@hotmail.com

On level six, (where you first discover the flood,) you get dropped off by your ship packed with eight grenades. This only works in multiplayer. If you want to know where the ship that drops you off goes instead of going back to space, then do as follows. When you're getting ready to get out of the ship, keep pressing the grenade button until it allows you to throw one. This is very hard to explain but... I figured it out because me and my friend were fooling around killing each other. Anyways..., you have to throw the grenade just before you jump out of the ship into the water like 1 or 2 seconds before and then the game will mess up and you will be stuck in the ship when it flies away. Just don't press anything while it is flying off or ysou will fall out. So now you know where the ship really goes to when you are doing the mission. E-mail me if you have any questions or anything else. 
Sent in by: talismans51406@hotmail.com

In the level called "keyes" after you get the chip form the captains head quickly run backwards and fall behind the platform, go underneath the wedge part of the platform and pick the invading flood off one by one, great when you are low on ammo and health.
Sent in by prnstar6699@netscape.net

Hilarious messed up covenant. This should work all of the time. I did it three times with me and my friend in multiplayer mode on heroic and legendary. So I haven't tested it on easy, normal or on campaign. On the fourth level, bring a warthog to where the covenant aliens close the door on you, (trust me the warthog can make it to there.) When you drive down there as fast as you can, before they close the door, ram the car into open door, (that of course hasn't been closed yet until they have seen you coming full speed with the warthog.) The warthog should be stuck in the door when it is closed and should be vibrating. Then when you go to pull a switch later in the game to open the door, the car will be popped out so you can get in of course, (or else you cant beat the game.) Then when you drive back there with your new warthog, (which is down the cliff outside the building where you pull the switch, and you can break your fall if you stay really close to the edge,) go in the door you opened run in there and there should be SOME frozen covenant aliens that haven't been loaded yet and if you throw a grenade on frozen aliens, they won't blow up. If this does not work it may be because of these reasons-not playing multiplayer-not playing heroic or legendary-didn't run in the door that you opened fast enough for them to not be loaded yet. P.S. It has worked for me three times, so it should work 100%. It's worked for me every single time I've done it, just haven't done it more than that many times because I played the level more than I wanted to. If you have any questions or anything, email me. 
Sent in by: talismans51406@hotmail.com

In the fifth level "Assault on the Control Room" , Get to where you must reach the third chasm, then when you find your marines, just  before a covenant drop ship arrives, you go through all that. Then you go through the little cave, then up a little hill, beat the covenant, then  through the door. And when you get into the room after the save point. All the covenant are sleeping. (EXCEPT THE COVENANT WITH THE PLASMA RIFLES, THE TALL ONE'S AS I LIKE TO CALL THEM, NOT THE HUNTERS THOUGH). So now all you have to do is be sneaky and sneak behind the tall ones and melee them. Or kill the grunts first. But in any case you can get through that part of the  level, without using any AMMO at all. If your seen just restart at the save point and try your luck again. NOTE: I did this on LEGENDARY, I don't know if it works on any of the other difficulties or not, I didn't pay attention.  Just make sure you get them all!! HAVE FUN KILLING THOSE LITTLE PESTS!!
Sent in by: X-CLUE-SIVE

Overshields-Two in the Pillar of Autumn level in one of the escape pods-Six in the fourth level, two near the first couple of hunters, three near the entrance to the second couple of hunters and one by a purple box near the edge of a ravine in the place where the aliens first locked the door in the huge building.
Sent in by: talismans51406@hotmail.com

Ultimate Snipering Technique:
Note: This cheat only works on Multiplayer.

Set the competition for all vehicles and normal weapons.
Choose Sidewinder as the level you want to play in.
Whenever you start to play grab a sniper rifle and another weapon of your choice.
Once your done gathering weapons and ammo jump in a tank.
Drive the tank up the cliff that is farthest out in the arena.
On this cliff there is a rocket launcher.
Drive past the rocket launcher to the doorway that leads to a teleporter.
Turn the tank to face directly at the lone tree in the middle.
Back up to the wall until the tank won't go further.
When you get out test to see if the tank is ready by going underneath it without crouching.
When you can go underneath it without crouching go grab a ghost.
Drive the tank up the same cliff as you did previously with the tank.
Turn towards the tank and then go full speed at the tank and use it as a ramp.
When you go over the wall where it looks like there is nothing beneath you you've done the hardest part.
Be careful not to fall or you'll have to do it again.
Now you run around the edge and snipe off your friends.
When they return fire just back up. 
Sent in by Clay Jones

IN the silent cartographer, get the two warthogs and full them with man. Then get the grenade launcher, blow both the warthogs in front of the men... The man starts to shoot at you!!!!!!! - Sent in By JBical@aol.com

Different Demos: - At the starting screen of Halo if you wait about a minute and 15 seconds you'll see a cool looking demo of the game. If you wait two more times you'll see two more demos. -  Sent in by: ElAndre13

Blast the Sentinels: - On the last level in the bridge room, you enter and go to the glass sign, then you'll go to a cut scene where Sentinels break the glass and try to kill you. But if you press A before that happens you'll skip it and you'll have a piece of debris to protect you while you blast the Sentinels. - Sent in by: ElAndre13

Easily Defeat the Tanks - On any level with a covenant tank, an easy way to beat them (if you don't have any rocket launchers) is to go up to where the nose of the tank is and fire away. Unless the tank moves you should be safe - Sent in by: ElAndre13

Good Pincushions:-  When in possession of the alien Needler, you can do some devastating damage. To maximize its effectiveness you should be a stone's throw away from your target. Make sure as many needles hit your assailant as possible. Since they explode  shortly after impact, you can cause an awesome chain reaction that is quite explosive to the now charred enemy and anything else in close proximity to your victim. 

Left Wide Open:-  If you're looking to to knock out the round shield wielded by the mid-sized aliens, then grab one of their weapons and hold the fire button down for a shot to charge. Now let it rip! It will permanently disable the bastard's shield, leaving him completely wide open.

Toro! Toro!:-  Don't back down from those huge mortar toting Hunters. Yes, they are massive, and yes they are pretty darn hard to kill. But this is what you do. Grab a few of those adhesive plasma grenades from fallen foes. When a hunter charges you, run backwards facing the brute and toss a few plasma grenades on the sucker. You need good aim. The adhesive grenades will stick to the Hunter leaving no way to remove them other than the inevitable explosion. BOOM!

Pistol-Whip It Good:-  Never underestimate the power of a well-placed melee attack. Smacking someone or something with the butt of your gun is great fun and immensely effective.

Bomb Onboard:-  Don't hesitate to stick a plasma grenade to any vehicle in the game. Sabotage is great!

Dealing with those pesky shielded aliens: - When going up against a group of the shielded aliens, a good way to take them out is too rush one of them, firing once a second or so to keep them behind their shield. They will turn and start to run when you get close enough, but they don't run as fast as you. Track them down and melee attack them in the back of the head for an instant kill and a good laugh. 
Sent in by: Andrew Sands

Defeating Jackels - Use a photon weapon to destroy a Jackel's shield quickly. 

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.

The Pillar of Autumn: Shields - On The Pillar of Autumn level 1, there are some empty airlocks that the Covenants have entered from. After killing the Covenants, go inside to find two extra shields. These shields are better than your normal shield protection.

The Pillar of Autumn: Different messages from Marine captain - Depending on which difficulty setting you select, the captain of the Marines says a different motivational speech. From something soft in the easy setting, to something brutal with the legendary setting. 

Flashlight - When you get to the part when the people and aliens infected by the flood start coming after you, turn your flashlight on and point it at them. The large one will stop running and jumping so that they are easier to shoot. However, if you raise your gun to reload, turn away from them or take the light off of them in any way, they will resume running around and try to kill you again. Although the creatures infected by the flood stand still when you point the flashlight at them, they may still shoot if they have a gun, so kill them quickly.

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

Secret Cave - There is in level 5 a secret cave at the button of the map entrance. It comes out on the side where they are not expecting a side attack from that side and it shall be easier.

Battling flood - Using a combination of assault, Shotgun, and grenades works best.

Note: Only use the "Sticky" grenades at a far distance, especially for the little ones.

Shot gun- use on big floods, and little floods. When those little guys, that jump up at you, are all grouped together use the shot gun, it shoots out a lot of bullets at a time. Also close to medium range range to the big guys.

Use Assault rifle if the guy is standing still, if he or you are moving too much it screws your aim very badly and you waste bullets and have to re load more often and then they have a clear shot.

Use grenades when you know something is behind a wall, or when you see a lot of flood coming at you from a safe distance.
Sent in by Carlos

INVINCIBILITY - At the Pillars of Autumn kill the captain with a plasma grenade, then after your marines start to kill you, blow yourself up with a grenade (only works on multiplayer). The invincibility takes effect on the next level.

Win more frequently - In order to win more frequently, look at your opponents box during multiplayer. 

New enemies - If you beat any level on legendary you will get new enemies.

Carry 3 Weapons - OK to carry 3 weapons u have to beat the game (i beat it on easy) then when you finish you 
can carry 3 weapons.

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.

Description of Weapons & Best Times to use Them + Vehicles:

HUMAN WEAPONS - Pistol- Has scope capabilities, grwat for picking off Covenant at semi-long ranges. NOTE- good for level three Sniper Rifle-Armor and shield piercing rounds, Good for cloaked Eletes ant semi-long ranges (u will see elete's camouflage shimmer slightly) Rocket Launcher-Basic Covenenat-killer, Great for masses of grunts, hunters (can be a 2 for 1 deal)and especially Flood Assault Rifle-Speedy, great for masses but not for sniping, OK with flood, and good with grunts

COVENANT WEAPONS:
NOTE-Cannot reload (must get new)
Plasma Rifle-Great for masses and elite's, use in short bursts to avout overheating (drains power quickly) Plasma Pistol- Good for eletes when cornered, Great for hunters when shot in back

VEHICLES:
Warthog-fastest human vehicle, good for hunters (machine gun on back)
Tank-The best for masses, and spectacular for hunters. Real messy however (turnes most covvant into mush and wreckes covenent vehicles
Ghost-Quick, hovering, OK shot but bad defense make this vehicle quite a dish, be careful howver u can get blasted easily.

Banshee - Only thing that can fly but the best damn thing for just about everything

Instant Kill - If you have a weapon go behind an enemy and press B and it will kill them automatically.

Kill Hunter - If you want to kill a hunter in one shot just get behind it and shoot it in the back with your M6D Pistol. ( this is alot easyier on multiplayer because you can use one person for a decoy.) 

Board Them - In thge very beginning of the game when you are trying to escape the Pillar of Autumn, you can find cloak devices and Overshields (shields that double over your existing shield). When you locate the area where the escape pods are, you should find a couple Covenant boarding pods. This is how they have boarded your ship through your empty escape pod airlocks. Within their boarding pods you should find a few handy items.

Best Anti-Flood Weapon - The combat shotgun is the best weapon when you fight the flood. It'll take them dow nin 1 or 2 shots.Forget the assault rifle or the plasma weapons shotgun is the way to go.

Overshields Over There - In the level "The Silent Cartographer" where you disable the security systems, theres three overshields near a couple of those purple barrel things. When you're about to enter the first hallway into the security disabling room, before you even go in the structure, turn left and there should be some purple container/barrel things, with three overshields littered around them. Have fun!

Banshees & Shortcuts - In the level where you charge the control room, the snow one, you can hi-jack an enemy banshee. When your in the corridor and it says "If I had a Super Weapon" in the bottom right hand side, you can snipe down the covenant that will get into the banshee. If you do snipe him down, make a break for the banshee and hop in. Even if you don't get the Banshee, you can still skip half the level by turning left as soon as you come out of the door and falling off the bridge. The wall will break your fall, so you don't get hurt, from there you can head up to the control room and beat the level in no time.

Get the Drop on the Dropship - When a drop ship unloads aliens, the next drop ship will hover in the air. If you take your sniper rifle and zoom in on the sides where the doors open, the targeting cursor will turn red. Fire once or twice and the alien will plummet to the ground. 

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.
Sent in Omar L.

Blue shields - In some levels there are blue shields that you can hide behind. Opponents cannot see you there, but you can see them.

Conserve ammo while fighting Flood - When fighting the Flood, only fight the combat and carrier forms. If you are against only a few of the little ones, do not shoot. Your shield will be able to take most of the damage. Only shoot them when they are in very big numbers.

Defeating Covenants - 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.

Defeating Elites - Find a needler and waste a clip on an Elite during the early levels. This will take out the Elite and the gathered needles form grenade-like explosions, injuring if not killing anything near the target.

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.

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 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 the human pistol, sniper rifle, and shotgun will kill them if you hit them there.

Defeating Jackals - Use a plasma weapon to destroy a Jackal's shield quickly.

Do it yourself grenade launcher - Get two plasma grenades. Place a grenade down, then place the second grenade in front of it about one to two feet away. Stand back, and when the first one explodes. it will sent off a duplicate of the remaining grenade. When one of the copies stays, the other blasts off in the direction the first grenade was sent it in. Wait for the second grenade's time to go off and watch the explosion either in the air or on the ground.

Double melee attack - Get a grenade, or play a multi-player game with infinite grenades. Melee, then quickly melee again while throwing a grenade (press B, then just as your character finishes his melee, press the L + B). If done correctly, your character will melee twice, but in-between melees throw a grenade. If your use fragmentation grenades in multi-player mode, other characters will not see you throw the grenade and can easily be destroyed by it. If your grenade is not plasma, it may bounce off your enemy and blow you up as well.

Easy Banshee kill - Wait until a Banshee is directly above you, then shoot it in the belly with your shotgun. On the easy difficulty setting, it will explode with one shot. Moving forward when you do this can keep the wreckage from falling on you.

Easy kills - To kill someone, it is often easier to run him over rather than shooting him. If you shoot him, it will take a few hits. If you run him over, it will take only one hit.

Easy shotgun reload - When you are reloading, quickly tap Fire. The reloading should stop and you will fire a shot. You should have half a clip remaining. Note: Only do this in an emergency, and it works best against the Flood.

Extra ammunition - If you shoot your fellow Marines you can pick up their ammunition. Make sure to only kill a straggler unless you are prepared to take on all of the Marines. They will turn on you if you kill more than one of them.

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 times.

Faster reloading - To reload most weapons faster, press X and shortly after that press B to melee. Note: For the shotgun this will cause you to stop reloading all together.

Fireworks - If you have just won a game or would like to celebrate, take two plasma grenades and throw them on the same exact spot. The first grenade will explode, sending the second grenade into the air. After about one to two seconds, the grenade will explode blue.

Flashlight - When you get to the part when the people and aliens infected by the Flood start coming after you, turn your flashlight on and point it at them. The large one will stop running and jumping so that they are easier to shoot. However, if you raise your gun to reload, turn away from them or take the light off of them in any way, they will resume running around and try to kill you again. Although the creatures infected by the Flood stand still when you point the flashlight at them, they may still shoot if they have a gun, so kill them quickly.

Flood infection forms - The Flood infection forms (the small ones) are deadly when you do not have a shield. Normally they pop, but without a shield, they drain your life slowly away. The only way to get rid of them is to run away, then shoot. Do not always shrug off the infection forms, as that can get you killed.

Glow in the dark blood - In dark areas, kill either a Hunter or a Grunt. Then, melee them so lots of blood comes out. Turn off your light and you will be able to see the blood.

Hippo shells - Fire a shotgun shell. Look at the shell with sniper rifle or pistol. You will see a hippo on the shell.

Making sure Flood are dead - After you shoot a Flood and it is on the ground, move your crosshairs over it. If it remains blue, the Flood is dead. If it turns red, blow it to bits.

More accurate plasma rifle - Instead of holding down Fire, tap it very quickly. It should shoot much more accurately and will not overheat as easily.

Playing in legendary mode: - Get a friend. Have your friend sacrifice himself until the room is clear. Always use a good combination of weapons, and think about your surroundings and enemies when choosing weapons. The sniper rifle is great until you reach the Flood. A good combination is the shotgun (the human pistol before you reach the Flood), an automatic weapon, and grenades. If you do not prefer to follow this example, then remember to use a combination of short and long range weapons.

Rocket Launcher instructions - If you have a gun with a scope, use it to look at the middle of the Rocket Launcher. You will see a small picture with a man holding the gun with the text "Hold This Way".

Scooping up weapons - You do not need to stop on top of a weapon to pick it up. Hold X while moving over a weapon and you will swap it without slowing down. It will even interrupt the reloading action initiated when you started holding X.

Stronger melee attacks - Jump in the air and your melee attacks will be stronger while you are falling.

Supercharged weapon - Whenever you have a plasma gun, when shooting hold R and instead of shooting one shot, it will shoot ten in one large blast.

Telefragged - There is a kill in the game known as Telefragged. To do this easily, play in multi-player mode on the Battle Creek level. Have player one go into the teleporter. When they get to the other side, move player one backwards until they are inside the teleporter. Then, have player two to go to the free teleporter and move into it. Player one's screen will start to go white. When the screen is completely white, player one will die and player two will teleport on top of them. At the top of player one's screen, the message.
Sent in by Devon Karr