Alright, this works with any dual wieldable weapons but I like the plasma rifle. What you gotta do is this:
Step 1: get your weapon of choice that's dual wieldable.
Step 2: have your secondary weapon as a different dual wieldable weapon.
Step 3: Get 2 weapons on the floor that match one of your weapons.
Step 4: If you have plasma rifles and a plasma pistol, get your plasma pistol out dual wield with the plasma rifle on the floor.
Step 5: Now you can hold X to swap for the third plasma rifle.
Step 6: You now have 3 plasma rifles, so enjoy.
Abcevil123 sayin, good luck killin stuff.

First of all this cheat works on all difficulties and I found this out one day while I was extremely bored

U want to take the sniper rifle from the sarge this is optional but I like to do this
Next you want to go to the building tht the elite is on the roof
Go behind this building and you will see a spot tht is a corner to you're left
Go inbto the corner and jump up onto the ledge you might have to crouch in mid jump to get up there
Now tht you are up on the ledge you want to turn around
U ill see another ledge
U need to jump ontop of it
So do a running jump and crouch fer saftey incase you didnt jump far enough
Now tht you are ontop of the roofs you can run around
Follow the rooftops to the right and you will see this weird object tht you have to cross it has 2 thin legs and a few feet farther there is a wider part tht has a hole in the top of it don't fall but if you do you can jump down to the ground and start over
Once you cross tht you will come to a ledge go to the far left and jump down onto the lower roof tops
There is another one of those wierd looking things tht you have to cross
Once you do this follow the roof till it ends
Then you have to jump across onto the higher ledge
Dont worry if you don't make the jump you can still get the sword
Go to the very end of the ledge and you will be next to the destroyed bridge
Jump onto the bridge and go to the far side and top of the bridge were it is flat
This next part is trickey but don't worry you can keep trying it untill you get ontop of the building
If you fall go back to the lowwer ledge tht you can get to if ugo to the place where the concrete peice has fallen and there is an alcove behind it
Jump up onto the crate and jump up you can get the sniper rifle here as well but this is not a cheat for sniper rifles lol
Once up on the lower ledg you need to get one of the crates to the very end of the ledge
My method of choice is to throw a nade at them and then bash the one closest to the end
Now tht you have done this get ontop of the crate and jump back onto the bridge and try again
U will have to crouch jump both of these
Once ontop of the building go streight and fall behind the extention of the roof
Go straight from there
Jum up ontop of the grey concrete things tht are ahead of you and onto the roof
Once ontop turn left and you will see a hole in the roof walk down into it it's not a big room nut you will see a blood splater and a sword most of the way into the ground go pick it up and enjoy slaughtering thing with the only sword on this map


HAPPY KILLINGS

My little brother showed me this little trick and I was shocked that it actually worked. Anyways, here's what you do:

1. Pick up a weapon you can dual wield (e.g. Smg).

2. Switch your secondary weapon with a different weapon you can dual wield (if it isn't one you can allready).

3. Dual wield that weapon with the same one as your primary weapon in your left hand.

4. Find a third of that weapon and switch it for the weapon in you're right hand.

You should now be holding 3 of the same weapon. This is particularly useful with weapons that use ammo (e.g. Smg, needler, etc.) rather than a charge (e.g. Plasma rifle)because it allows you to carry 3x the ammo instead of just 2x for dual wielding.

Once again, I give all credit to my little 5-yr-old brother.

When you start off quartine zone (on lgendary by the way).
Turn directly around there is a tunnel go throught it. Once on the other
Side walk forward and you will see a little ledge walk on it being careful
Not to fall.
ok at the end will be a floating skull this allows you to jump
Higher when doing a grenade hop.

1.) now go back down the ledge a little ways and look for a small yet
Tall cliff/ridge like thing.
2.) grenade hop frags work best but plasmas are good 2. Itll take a few tries
But once up walk to the far back.
3.)when there the robots a.k.a the oracles robots will attack you
When they do they can't hit you this is a awesome glitch and fun
To do when you get bored with campagain mode.

I'm not sure if the ownage works because my mate gave the cheat to me I will make him feel the wrath of the grunts in uni if the cheat is wrong his name is jack crooks(the enemy)

Well on the level "the great journey" after sgt.jonson blows the door up like hell fly a banshee{the one you're driving]into the walls from left to right until the banshee has very small wings and then fly through the rooms inside that door beware of the brutes!!!!!!!! Then a cutscene should play triggering the fight with that damn traitor tartarus any way lob a plasma grenade at miranda keyes head she will then fall to the ground tartarus will try to kill her oblivious to you and the just own him with your covenant[they rock humans suck] energy sword wow you've owned tartarus and if this don't work i'll eat my hat loll xd.

Ok you can do this cheat where ever you have a warthog or scorpion flip the warthog or scorpion to put it on it's side hop on it don't flip it yet flip it when you are oniy then you fly quite a ways

Ok go to the level gravemind and make sure you get the bruteshot from the captan brute and reload it in necessary then kill all the other enimies with your secondary weapon.when the brute on the intercom says"all approches to the holding pen slay the demon on sigh".get out the bruteshot and follow the jakels into the room and blow them up.oh yah make sure you have four or atleast one plasma grenade and the sputnik skull is on. Smack a body in to the wall and make sure the body frezzes. Finaly stick a plasma grenade on the body and it should not blow up but just stick there.then turn on your flashlight and the screen will flash.

If you go to delta halo and go to a hill like the first one you come to (where the jakels with the snipers are) turn to your left with a ghost and power bost untill you go up the hill. Don't worry you wont die unless you fall off your ghost. If you hurry when the pelican drops of the tank get a ghost and go to the rock and try to beat the pelican to the hill. If you do you can drive the pelican around the level.

Okay this trick can take out a tough enemy really fast. If you lay down a spike grenade next to any enemy like a Grunt ,then trap it in a bubble shield when the grenade explodes the spikes will bounce around rapidly! This will slaughter the enemy in the most brutal way possible. Hope this helps.

On the great journey when you face tartatus stay where you are at the beginning then whenthe platforms come around on one Keyes daughter is on one and if you shot her she won't die

You know the banshees you get on the great journy....well if you brake both the legs off (or wings) you can get into the room that Johnson brakes open with the scarab (giant robot veical of covenent) then own the brutes inside of it. Also if you are lucky when you enter the boss room with tarterus, if you go backwards to the hallway the banshee might be there,
(only worked for me half the time).

You aim any gun at a marines head. The you keep the crossshair(target)just on the helmet and make sure it is white but is still on his head and fire until the helmet falls off because if you go too long you could kill the marine.

On the level Regret when you are at the first island temple and you are finished shooting all the Drones and Jackals and the elevator is about to come up throw 1 plasma grenade and 1 frag grenade. The explosion will kill the Jackals before the lift doors even open. Therefore you will not have to use your weapon ammo.

If you go to the level regret on easy go to the first gondola ride after you fight the hunters and snipe the grunts and jackals and whne you walk in the door there is a block with 2 jackals hiding behing it and you can jump on it and then there is a ledge right above you jump on that and go out to your right out the door you should be where you sniped the jackals and the grunts turn around to where your looking at where you came out of and when you look to the right there is a ledge that you can hop on to let you get on top of where you came out of the just follow the ledges around the building and it should be sitting right there on the ground.............i still don't know what it does but when you melee someone they die the very first time ?????

I thought this was by luck but it was by diffculty.

When you start metropolois, there will be a scarb cutscene(sry for spelling errors) if you put easy there would be a diffrent conversation between Johnson and the marine than normal(you get what I mean) so put on subtitles to truly reveal what they say.

Happy Translating!

2 players needed
Get 1 person to stand on another make sure the one on top has a plasma grenade
Person on top sticks the one on the bottom just before the grenade blows up the person on the bottom jumps(make sure person on top dosent fall off)once he or she has jumped the person on top jumps sending the person on top double hight the grenade will blow up and send the person on top a extra 2ft or so and when
The person on top is in the air press and keep hold of crouch and he or she should go about 10ft in the end the better you time the jump andgrenade the higher you will go.

At the beginning at one point before the hunters you may have seen a red elite jump down from the roof tops the way to get up there(need 2 players to progress furthe on the rooftops)is to jump on the red van that is totaled then jump onto the ledge across from it and go as far left as possible then look up you will see a black ledge this may take a few trys to get up there it took me about 20 mins jump onto the building walk along the metal roof a carry on exploring me and my mate got about 50ft above hotel zannzibar also when you are as far as we got the game scenery ends so you just see the sky and blackness throw a grenade out there and it just spins while staying still(it will blow up so stay back)
When you get on the really high buildings you will experiance serious lag.the reason you need your freind is because you have to do quite a few friend jumps.

First you select the level metropolis, then when you start the level kill the two marines then get in the tank and go to the tunnel( make sure to destroy all the ghosts,wraiths and all but one banshee! ) when you enter the tunnel MAKE SURE THE ONE BANSHEE THAT YOU DIDN'T KILL IS FOLLOWING YOU! Destroy everything in the tunnel except the banshee. When you get over the two walls there will be a passage with a red light, go through it, now the hard part.there is a little round tunnel that you have to go through to beat the level right? Well go through that tunnel and make sure that the banshee is in front of you in the tunnel it will say loading as soon as it does get in the banshee, if you don't the banshee will disappear! Now when you get out of the tunnel fly left then up to two buildings with two bridges connecting them, go to the one closest to you, and in the middle there will be a plasma rifle, only it is the scarab gun (Note: It will be floating over a caution cone type thing!)

This is anot very interesting, but I thought it would be good for a laugh.
There is a multiplayer arena with a billboard that has a yellow warthog on it, the arena looks like a construction site, I don't know what it is called.

Take a rocket launcher and go up the dirt hill at the broken bridge, then turn right into the small opening. Move until there is a small bridge to get to the

Garage, next to the two warthogs. Don't go in, turn to the narrow balcony to the right and look for the turret sitting on the edge. Back up from it to where you can still shoot it and blast it with a rocket, after you have destroyed it, go up and you can get on it and shoot still, as if nothing happened.

Ok on get the sputnic skull and go through outskirts untill you get to the outpost where the ship and the pods are and go into the sniper hut thats floating use the sabersword in the stone earlier in the level to keep meleeing the wall in the direction of the oputpost till it falls!!!! Then use the wartog to push it to where you want!!! Then if you go in the beam you just float at the topof the beam!!!!(try different items on the pad and if one floats you can use that instead!!!!

First get the sputnic skull (you can find how to get it in walkthroughs) and go to outskirts.then when you can move take the sg. Sniper rifle and give him a good gun for trade or he will be just a decoy if in high difficulty. Then go to the large box and look up at the building next to it neer the hunter spawn and you can see a row of glassless windows push the box under them and jum on the box then crouch jump into the window.when you hit it you wont just get in you will have to walk across the windowsills untill you fall in. Then you can snipe freely timll hunters.

When you have reached a level where you lead Marines or Covenant you'll be able to perform this sneaky little trick which should keep you alive a little bit longer. If you've got powerful weapons which are low on ammunition or power give them to the A.I. That follows as they'll never run out and they are more than competent with them.

Okay, here's what you do, you go to the level Quarentine Zone and turn around once the level starts and go through the cave and try to find a long ledge that leads into a fog, this MUST MUST be on lengendary, there will be a skull floating there, hold X and collect it, then exit the level, no go to that level after outskirts,(sry forgot what it was called), and go up to the part when you go through the sewer tunnel, then take that warthog that the dude wants you too shoot in and kill all the aliens and he'll take you to a path near a few ghosts nad a wraith, when you destroy evrything there he'll take you through another tunnel and once you get through exit the warthog and there will be a huge cracked window right in front of you, no jump onto the ledge and use a grenade jump, which the skull you obtained lets you grenade jump higher then once inside you jump on a silver that looks like a radio antenna and jump on another one ahead of you thats hangin in the air then jump onto the ledge and jump onto a higher ledge and then go into an edge between two buiidings and BAM! Theres a huge soccer ball there, now you need to melee it to get it down onto the street, then you can take a ghost with a friend to play soccer, which gets kinda stupid in about five minutes, c ya and wait for my info on how to get a plasma rifle lokkin scarab gun on the same level!