� A skull similar to the one that activates blind mode can be found if you Start on "regret". After the first lift ride (before the first underwater elevator), grenade jump from the front awning of the lift to the ledge in front of you (the one with two turrets).

Grenade jump AGAIN onto the next ledge.

Make your way to the back of the building. On Easy, you'll only find the Assassin skull. On Legendary, however, 2 invisible Elites carrying swords just shake their heads wildly, ignoring you completely.

� At the beginning of Outskirts jump on top of the light on top of the door with a crouch jump, then jump to the left platform. Turn to your left and go down the long dark corridor and pick up the skull; it will say blind and your screen will flash black for a while. In this mode you can not see your weapon, body, shields, ammo, or radar. To get rid of this feature use the following method: 1. Turn off your XBOX or Save and Quit. 2. Go to Campaign and select level and choose Cairo Station. 3. Skip the cinematics and then Save and Quit. 4. Go Outskirt and your hud is back.

� Right after you get out of the sewers (Tunnel), there is a big area and 2 ghosts, kill every thing first, then go to the middle of it where you see a arc that leads up onto a building, throw a grenade down and jump by it to get enough height to start climbing it. When you get to the top take a left and hug the wall around the structure and the Catch skull will be there.

� On the level "Delta Halo" on Legendary Difficulty, Progress until you reach the area during the "Push through the covenant held ruins" where you have to clear a Landing Zone for the Pelican to drop weapons. You will know you are in the right area when cortana says "they're pouring out of the center building". Anyway that area has Plasma turrets along its borders. A little bit after the left side turret you will see the outline of a door in a wall, but the door has a solid rock slab in it and a rock in front of it. Jump on the rock then jump to the ledge above the door then jump on the ledge to the left. Now jump onto the building with the sealed door using grenades. Atop the building you will find two dancing elites and the "Envy Skull". Pick up the envy skull and you will be able to use Active Camoflage like the Arbiter.

� After you get off of the slowly decending elevator in "The Oracle", you will come to a hallway where you see a handful of dead bodies. Continue into the next room, and you will be on the second floor of a room that has windows. When you enter this room, look to the right, and find the third pane of glass. It should be to the right of a wall that has some flood guts splattered on it. Shoot out this window, and either window directly across the room. If you look below you will see a platform that has four tall posts. On the far side of the room there is a column that is right in between the two windows, on the far side of the room. Turn on your active camo, and jump to the center platform. Jump on either of the posts on the far side of the platform and jump to the column between the windows. Make another jump through the window you shot out and make a left. Walk all the way to the end and you'll find four flood elites convulsing on the floor, with the Famine skull in the middle of them. When you have this skull all weapons will have less ammo.

� On the last Master Chief Level, on Legendary Difficulty, when you enter the final Gravity Lift, look up. A skull will pass through you extemely quickly so you must start holding X a bit before you actually pass it to grab hold of it. Once you grab the Iron Skull, Iron Mode will be activated. This skull causes you to go back to the last checkpoint when you die in co-op mode.

� In "Sacred Icon" there is a semi outdoor area which has the same type of area right next to it. There is a large sentinal in front of each one. Go past this area and down the piston and you'll be in a vary dark and dank flood infested area. There's a stack of 6 or 7 boxes as you enter the room. Use them to jump up to the landing above. There are a handful of alcoves on your right hand side. The Mythic skull is in the third alcove, floating above a dead human flood.

� At the start of "Quarantine Zone" turn directly around, and you should see a tunnel. Head down the tunnel and go straight until you exit it. Go straight across the open area, and you'll come across a broken pipe tunnel on your right. Straight in front of you is a small ledge running across the wall, above the green pit. Carefully get onto that small ledge and walk all the way to the end of the ledge to find the Sputnik skull. In this mode explosion force and melee force is greater.

� On the level "Cario Station" on legendary, make your way to the "Priority Shift" checkpoint. Progress until the room with mounted plasma turrets, right after the armory with the Elites. Clear out this room, and get on the raised area with the plasma turret that is on the side of the wall where the window curves. Look for two parallel beams on the ledge above. Climb up the supports for these beams and crouch jump up onto the upper ledge, then onto the beams themselves. Walk in the direction you came from and there will be a small ledge sticking out to the left, jump on it and pick up the Thunderstorm Skull from inside the trash container. This turns all Covenants into their spec ops rank.

� At the begining "Armory" wait in the room until the Sarge starts telling you to get into the elevator. You MUST wait for him to say "Would it help if I said please?" When he says this, get into the elevator and go down to the tram. Get on the tram and face towards the INSIDE of the building. Press up against the glass doors towards the inside of the building. You should hold 'X' down, and you should pick up the Unknown skull. It's on a stack of green crates, near the end of the tram ride.