I found this on another forum. I hope this helps some people out.
About Skulls in Halo 3
Skulls were first introduced in Halo 2, where picking up a hidden skull in the “Legendary” game difficulty would create an undesirable effect against the player (such as not being able to see anything on their HUD). In Halo 3, skulls can be found scattered throughout the levels on Normal, Heroic, and Legendary difficulty settings. Picking up “Golden” skulls will also unlock an achievement on the Xbox 360. After picking up a skull in the game, you can enable the skull’s effects in Meta Games, which will in turn multiply your meta game score.
Overall, Skulls can make for a very interesting play experience, and really help to show who is the Master of the game through meta game scores.
Iron Skull
If you die, you restart from the beginning of the level.
Iron Skull Location
The “Iron Skull” is located at the very end of the first level, “Sierra 117″. It is located behind the building where Sgt. Johnson is being held captive, up on the roof. You can gain access to the roof on the far right side of the building. Travel all the way over to the left side of the roof, and the Skull will be concealed in the corner.
Black Eye Skull
Black Eye Skull Effect: When you lose shield, the only way to get it back it to melee an enemy.
Black Eye Skull Location:
This Skull is located in the beginning of the second level “Crow’s Nest”, the very room you start in. Hanging down from the ceiling is some piping. On top of this piping, on the side nearest to the large display (the one that Hood appears on) lies the “Black Eye Skull”.
You can gain access to the pipes a few different ways.
Tough Luck Skull
Tough Luck Skull Effect: Your enemies never back down, always make their saving throws, and always charge you.
Tough Luck Skull Location:
The “Catch Skull” is found on the third level, at the point in the level when the huge covenant cruiser flies overhead. On your left is some large piping following the road you are walking on. Underneath this piping are some support beams that extend out over a cliff. Jump onto the first of these beams, and travel to the end of it. Look to your left, and the Tough Luck Skull will be sitting on a rock extending from a cliff edge.
Catch Skull
Catch Skull Effect: Your Enemies throw LOTS of grenades.
Catch Skull Location:
The “Catch Skull” can be found on the fourth level, in the first area where you need to destroy the Wraith Tanks. When you enter this area, do not eliminate the Wraith Tanks (The skull appears when the tanks appear, and disappears when the tanks are destroyed). The Skull is located on top of the circular building next to the Anti-Air Tank. You can access the roof using a grenade jump, or jumping on the back of a hog.
Fog Skull
Fog Skull Effect: “You’ll miss those eyes in the back of your head.” You lose your motion sensor.
Fog Skull Location:
The Fog Skull is found on the level “Floodgate“, at the very beginning of the level. As you are walking down from the anti-air gun you destroyed in the previous mission, you encounter a ramp (next to a missile launcher). Around this ramp, you hit a checkpoint. At this point, you should also hear a marine yelling, “There! Over There!”.
You have a small window of opportunity at this point, but it is fairly easy to get the Fog Skull. Look up, and to the right, directly at the roof of the building next to the missle launcher. There is a single flood form (not to be mistaken with the two other flood forms jumping in front of you) which is holding the skull. Kill him before he jumps, and he will drop the skull down to the ground where you can retrieve it. Too early, and the skull will get stuck on the roof though, so just time it carefully.
Famine Skull
Famine Skull Effect: Enemies drop 50% of the ammo they usually drop.
Famine Skull Location:
This skull requires a bit of grenade jumping skill/luck.
You can find the “Famine Skull” on the sixth level, near the point where the path you follow branches off into two sections (one leading to the area where you need to let the tanks across the bridge, and the other leading towards the area where you meet up with the frigate). Take the right path, as you would if you were completing the mission, and you’ll notice a structure above you / to the left of you (near the area where you encounter a few ghosts).
You need to scale the rocks to the right of the structure, and then travel across it so that you pass 3 of the large support beams extending into the cliffs. Inside of the fourth support beam, lies the Famine Skull. A well placed grenade should have you up there in no time!
Thunderstorm Skull
Thunderstorm Skull Effect: All enemies are given a field promotion, and ranked up to their next available level.
Thunderstorm Skull Location:
The “Thunderstorm Skull” can be found on the level, “The Covenant”, after you take command of one of the Hornet vehicles. Fly towards the second force field generator (the one the Arbiter disabled), and land. The skull is waiting at the very top, at the end of the ramp extending over the sea.
Tilt Skull
Tilt Skull Effect: Makes enemy resistance much greater. For example, Brute power armor becomes nearly impossible to take out with nearly anything except for plasma bursts.
Tilt Skull Location:
The “Tilt Skull” is found on the level “Cortana”, in the circular room where Cortana mentions that she “Likes to play games too…”.
It’s a bit difficult to get to, as it requires getting on top of the ceiling of the room. Upon entering the room, head towards the left side where you will see some mushroom shaped extrusions along the wall. Get on top of these, and then look up and towards the right for another set of extrusions. Jump to these. From here, you should be able to jump on top of the ceiling of the room, where the Tilt Skull lies in the center.
Mythic Skull
Mythic Skull Effect: All enemies have double their usual health.
Mythic Skull Location:
This is probably the easiest Golden skull in the game to get. It is located in the very beginning of the final level in Halo 3. Begin by heading into the canyon, but hug the right wall. Very soon, you will notice that there is a turn to the right that is off the normal trail. Head a bit down this path, and the “Mythic Skull” will be sitting there.
About Skulls in Halo 3
Skulls were first introduced in Halo 2, where picking up a hidden skull in the “Legendary” game difficulty would create an undesirable effect against the player (such as not being able to see anything on their HUD). In Halo 3, skulls can be found scattered throughout the levels on Normal, Heroic, and Legendary difficulty settings. Picking up “Golden” skulls will also unlock an achievement on the Xbox 360. After picking up a skull in the game, you can enable the skull’s effects in Meta Games, which will in turn multiply your meta game score.
Overall, Skulls can make for a very interesting play experience, and really help to show who is the Master of the game through meta game scores.
Iron Skull
If you die, you restart from the beginning of the level.
Iron Skull Location
The “Iron Skull” is located at the very end of the first level, “Sierra 117″. It is located behind the building where Sgt. Johnson is being held captive, up on the roof. You can gain access to the roof on the far right side of the building. Travel all the way over to the left side of the roof, and the Skull will be concealed in the corner.
Black Eye Skull
Black Eye Skull Effect: When you lose shield, the only way to get it back it to melee an enemy.
Black Eye Skull Location:
This Skull is located in the beginning of the second level “Crow’s Nest”, the very room you start in. Hanging down from the ceiling is some piping. On top of this piping, on the side nearest to the large display (the one that Hood appears on) lies the “Black Eye Skull”.
You can gain access to the pipes a few different ways.
Tough Luck Skull
Tough Luck Skull Effect: Your enemies never back down, always make their saving throws, and always charge you.
Tough Luck Skull Location:
The “Catch Skull” is found on the third level, at the point in the level when the huge covenant cruiser flies overhead. On your left is some large piping following the road you are walking on. Underneath this piping are some support beams that extend out over a cliff. Jump onto the first of these beams, and travel to the end of it. Look to your left, and the Tough Luck Skull will be sitting on a rock extending from a cliff edge.
Catch Skull
Catch Skull Effect: Your Enemies throw LOTS of grenades.
Catch Skull Location:
The “Catch Skull” can be found on the fourth level, in the first area where you need to destroy the Wraith Tanks. When you enter this area, do not eliminate the Wraith Tanks (The skull appears when the tanks appear, and disappears when the tanks are destroyed). The Skull is located on top of the circular building next to the Anti-Air Tank. You can access the roof using a grenade jump, or jumping on the back of a hog.
Fog Skull
Fog Skull Effect: “You’ll miss those eyes in the back of your head.” You lose your motion sensor.
Fog Skull Location:
The Fog Skull is found on the level “Floodgate“, at the very beginning of the level. As you are walking down from the anti-air gun you destroyed in the previous mission, you encounter a ramp (next to a missile launcher). Around this ramp, you hit a checkpoint. At this point, you should also hear a marine yelling, “There! Over There!”.
You have a small window of opportunity at this point, but it is fairly easy to get the Fog Skull. Look up, and to the right, directly at the roof of the building next to the missle launcher. There is a single flood form (not to be mistaken with the two other flood forms jumping in front of you) which is holding the skull. Kill him before he jumps, and he will drop the skull down to the ground where you can retrieve it. Too early, and the skull will get stuck on the roof though, so just time it carefully.
Famine Skull
Famine Skull Effect: Enemies drop 50% of the ammo they usually drop.
Famine Skull Location:
This skull requires a bit of grenade jumping skill/luck.
You can find the “Famine Skull” on the sixth level, near the point where the path you follow branches off into two sections (one leading to the area where you need to let the tanks across the bridge, and the other leading towards the area where you meet up with the frigate). Take the right path, as you would if you were completing the mission, and you’ll notice a structure above you / to the left of you (near the area where you encounter a few ghosts).
You need to scale the rocks to the right of the structure, and then travel across it so that you pass 3 of the large support beams extending into the cliffs. Inside of the fourth support beam, lies the Famine Skull. A well placed grenade should have you up there in no time!
Thunderstorm Skull
Thunderstorm Skull Effect: All enemies are given a field promotion, and ranked up to their next available level.
Thunderstorm Skull Location:
The “Thunderstorm Skull” can be found on the level, “The Covenant”, after you take command of one of the Hornet vehicles. Fly towards the second force field generator (the one the Arbiter disabled), and land. The skull is waiting at the very top, at the end of the ramp extending over the sea.
Tilt Skull
Tilt Skull Effect: Makes enemy resistance much greater. For example, Brute power armor becomes nearly impossible to take out with nearly anything except for plasma bursts.
Tilt Skull Location:
The “Tilt Skull” is found on the level “Cortana”, in the circular room where Cortana mentions that she “Likes to play games too…”.
It’s a bit difficult to get to, as it requires getting on top of the ceiling of the room. Upon entering the room, head towards the left side where you will see some mushroom shaped extrusions along the wall. Get on top of these, and then look up and towards the right for another set of extrusions. Jump to these. From here, you should be able to jump on top of the ceiling of the room, where the Tilt Skull lies in the center.
Mythic Skull
Mythic Skull Effect: All enemies have double their usual health.
Mythic Skull Location:
This is probably the easiest Golden skull in the game to get. It is located in the very beginning of the final level in Halo 3. Begin by heading into the canyon, but hug the right wall. Very soon, you will notice that there is a turn to the right that is off the normal trail. Head a bit down this path, and the “Mythic Skull” will be sitting there.
