When playing Halo 3, there are hidden items called "skulls". Throughout the game there are thirteen in total, and when they have all been collected, there are special game features and content that will be unlocked and available. In the game, skulls are just that, a human skull. By picking up the skull, players activate it and can move along in game play. To utilize this feature, the level must be started on normal or higher. Once a player has found a skull, they only need to pick the item up. To activate the skull during play, simply navigate to the Campaign Lobby and activate the desired skull. http://halo.wikia.com/wiki/Halo_3_Skulls
Finding the skulls may prove challenging, however each skull is listed here, along with level, power and location.
Halo 3 Silver Skulls
- Blind - Level Sierra 117: Heads up display is disabled. Location: There is a large body of water where you first contact the Covenant. Jump onto the protruding rock and then the next. At the end is the skull.http://halo.wikia.com/wiki/Halo_3_Skulls
- Grunt Birthday Party - Level Crow's Nest: Effects of head shots such as confetti. Location: The pipes where the Drones fly into, reach the botom and go to the end of the corridor to the purple pipe. Do not jump down, instead go to the ledge with the green arrow. Go to the end of the passage to retrieve the skull. http://halo.wikia.com/wiki/Halo_3_Skulls
- Cowbell - Level The Arc: Physical impulses increased. Location: At the highest section of the hallway after the room of Plasma Batteries. http://halo.wikia.com/wiki/Halo_3_Skulls
- IWHBYD (I Would Have Been Your Daddy) Skull - Level Covenant: Funny new dialogue. http://halo.wikia.com/wiki/Halo_3_Skulls
Halo 3 Gold Skulls
- Iron - Level Sierra 117: 3x multiplier: Returns players to last checkpoint after death. Location: When rescuing Sargeant Johnson, cross the bridge and keep to the right. Jump onto the block lined with pipes. Jump up to the balcony and follow it to the end. In corner behind a pillar is the skull.http://halo.wikia.com/wiki/Halo_3_Skulls
- Black Eye - Level Crow's Nest: 1.5x multiplier: Affects recharging energy shield during melee attacks. Location: At the start of the level stand directly in front of the barracks doors and then turn around. Jump onto the green rack. Jump to the red beam to your right.Jump up to the black pipe to the right, at the end is the skull.http://halo.wikia.com/wiki/Halo_3_Skulls
- Tough Luck - Level Tsavo Highway: 1.5x multiplier: Effects enemies ability to dodge attacks. Location: In the level when the Covenant CCS-class Battlecruiser flies overhead, you will see yellow ladders to the left. At the top jump over the metal bar on the right and then turn left. Jump onto the black support below. At the end of the support turn left. Jump across the gap to retrieve the skull.http://halo.wikia.com/wiki/Halo_3_Skulls
- Catch - Level The Storm: 1.5x multiplier: Affects enemy grenade throwing. Location: Once Lakebed A has been reached, the skull is on the silo.http://halo.wikia.com/wiki/Halo_3_Skulls
- Fog - Level Floodgate: 1.5 multiplier: Motion tracker is disabled. Location: Once you see the Flood Combat Form jump from a rooftop in Voi, you can shoot it to make it drop the skull or or shoot the right arm.http://halo.wikia.com/wiki/Halo_3_Skulls
- Famine - Level The Arc: 2x multiplier: Reduced ammunition for weapons dropped by enemies. Location: At the fork in the road, go toward the bowl and drive to the right directly into the rock wall. Underneath the platform, climb the rocks to the right.At the end of the platform, jump up to see the skull. Using a grenade, rocket jump or other method of boosting yourself, you can reach the skull.http://halo.wikia.com/wiki/Halo_3_Skulls
- Thunderstorm - Level The Covenant: 1.5x multiplier: Enemies are promoted to the highest rank. Location: Fly to the tower with the terminal. Reach the extended portion that is over the ocean, at the end is the skull.http://halo.wikia.com/wiki/Halo_3_Skulls
- Tilt - Level Cortana: 2x multiplier: Enemy weaknesses doubled. Location: In the circular room, make your way to the top, the skull is in a pile of bones on the roof. http://halo.wikia.com/wiki/Halo_3_Skulls
- Mythic Level Halo: 2x multiplier: Provides Covenant twice as much health. Location: Move forward along the right side of the wall and enter a tunnel on the right. A cave will open, move inside and the skull is at the dead end. http://halo.wikia.com/wiki/Halo_3_Skulls