well, it's easier if u you see it in person, but i'll tell you the best way i can.

To start, get in a hog, drive it to either base. make it face a little to the left, or
right so it doesn't fall in that hole ( Why do they put that there? It's so stupid! ) Get
a rocket launcher or fuel rod, get either grenade. throw the grenade under the bumper of
the hog, IMEDIATLY shoot a rocket in the same spot.

If done correctly, the hog will be on the base

when your fighting alot of little floods like 100 run and find a door quickly go on the
other side the floods cant open the door when the door closes  what a minute and throw
some grenades near the door on your radar some floods will die this will help when you
dont have much health

To easily kill the hunters, grab a pistol, get up close to where they will charge you.
when they do this, start backing up so you don't get nailed by them, and when their
stomachs show, shoot them with the pistol.

use a ghost in the rocky place and hit the rock and jump off

  If there is a carrier and a combat form standing next to each other, don't shoot the
combat form.  Shoot the carrier and they will both die. 

If a Flood guy comes at you, use your flashlight and point it at them.  They will pause
for a second and you can blast them easily.

cheat_medusa <0 or 1> - Instant deaths for enemies that see player
speed <0-20> - Set game speed game
cls - Clear console window
cheat_bottomless_clip <0 or 1> - Unlimited ammo and no overheating for weapons
cheat_infinite_ammo <0 or 1> - Unlimited ammunition
cheat_super_jump <0 or 1> - Super jumps
cheat_bump_possession <0 or 1> - Possess touched character
cheat_deathless_player <0 or 1> - Invincibility
cheat_spawn_warthog - Spawn Warthog
cheat_all_powerups - Spawn all power-ups
cheat_all_vehicles - Spawn all vehicles
cheat_all_weapons - Spawn all weapons
cheat_teleport_to_camera - Teleport player to current camera position
quit - Quit game

Ok on the mission pillar of autumn after you meet with cpt.keyes go into the mess hall
like always. Try to get as much ammo as possible for ur pistol and assualt rifle. After
that run back to the bridge and kill cpt.Keyes (u can shoot him but i usually just wack
him with my gun) after that cortana is like wats wrong with u chief? So she'll call
security. Then look forward of where u killed cpt.keyes where the nose of the bridge is
its like all glass. Run over there jump down and kill the 2 crewmen above you. You will
then here the marines goin where'd he go? Climb up the ladder and start shooting the
nearest one. You will soon see that they won't die. When u need a recharge on ur shields
go back to the hole you found earlier and wait for ur shields to recharge. When you run
outa ammo use ur guns and melee them. Have fun making a blood bath!

on the level halo were you go inside to were you have to destroy 4 or 5 generaters destroy
1 then the next 1 use a plasma grenade and rocket launcher also use 2 frag grenades if you
do it right youll fly super high so high it will put you in a room thats lock were the
door is at. when your in side youll see these lockers standing next to each other. use a
plasma grenade to open it. when it opens a costum comes out. its a hunter costum press e
to put it on. then you be in thirdpersonview but you still look like the mastercheif.
revert to the last checkpoint then youll be a hunter. NOTE:its best if you try this in
multiplayer

on the begging of the 3rd level,after the battle get the warthog and go backwards on the
island. you should come up on a crashed warthog and more guys take them out and then move
up and take out the hunters.you should have another little battle further up.once you get
to the temple go down and turn off security. there will be some guys but nothing you cant
handle.once you turn it off cortana will say "this isint the map room"etc.now go back to
where you started.get some fresh marines and go to the map room. when you get to the
little hallway with the door it should be open and when you go through the gold guy should
be gone.then just fifish the level.

Ok Good Day. Go To Blood Gulch. Get into a banshee. Fly to the Right where you see a cliff
going down a bit. Go There. Turn Banshee BackWards and when its stops Jump Out. The Your
On Snipers Rock> Warning Bring Sni per.Also YOU.JUMP DOWN YOU DIE :D

When your playing multiplayer in Blood Gultch, go into the caves with a corner. When an
enemy starts shooting at you, go behind the corner so they enemy can only see you on the
radar. Whenever you are not moving you wont appear on the radar. So, if you stay still the
enemy will think your a dead. He will come around and then you get stick a plasma on him
or nail him with a shotgun. It works better when you hide behind the corner that you drop
your gun so it looks like you really did die.

{if your facing for or more people}in the level sidewinder go to red base and get the
sniper and shotgun use the niper on top to snipe out the enemy people in snipe range and
if no ones in range be patient they will come, if they get in the base use the the shotgun
for close comat and melee if your losing use the portal to escape {if they follow I can't
garantee survival}.

This trick only works on Blood Gulch.

Get on top of the base and get the sniper rifle (or get the rocket launcher. which ever
one u like the most).

Then get into a banshee and fly to the red side.

If u know where the plasma grenades are go there.

u will see a wall that comes from the ground and goes over the plasma grenades. Land the
banshee right in front of it. Fly straight up where the flat part is. Get as close to the
flat part as possible. Look as straight up as u can. If done correctly u will fall out of
the banshee and will land on the flat part. If u dont get up the first time keep trying
over and over again u will get it.

when yor in the pelican on the lvl 343 guilty spark as sune as yu gain control of chief
chuck a grenade yu will stay in the pelican walk along and look down the edge and yu will
se lites jump down to the ledge covenant jackals&grunts will run out. jump down turn
around quickly and yall se floating ARs!!!!!

get in warhog and put a gunner in back and when in air shoot and u will automatically die!

in keyes, in the begining,when you find the shield,shoot it then stand on its arm and when
it comes back you might be in the cieling.

note when in the cieling carefully jump over the locked door to skip a chunk of the level
and immediatley start by meeting keyes