Skulls are hidden objects in each campaign level (or now in the new multiplayer levels , I think) When you pick up a skull you "unlock" it, in the sense that you can now use it's ability in campaign. When you activate the skulls they actually have a negetive effect on you, and make the game even harder. The reason why people would do this is because it adds a bonus when you are playing to get a score ( You get an achievement when you get a certain score).
Also, if you find all thirteen skulls, you can unlock the Hayabusa armor.
Or maybe you mean, "Which are the skulls in Halo 3?". Well, here's a list.
Iron
Black Eye
Tough Luck
Catch
Fog
Famine
Thunderstorm
Tilt
Mythic
Blind
Grunt Birthday Party
Cowbell
IWHBYD (I Would Have Been Your Daddy)
Blind skull on sierra 117 Black eye skull crows nest tough luck skull tsavo highway Fog skull flood gate Famine skull The ark cowbell skull the ark thunderstorm skull the covenant i would of been your daddy the covenant tilt skull cortana mythic skull halo
Skulls are hidden in every level and can be found and picked up.
Once picked up they are unlocked and can be activated.
Once activated they make your game harder and more challenging.
There are 6 skulls located in the multiplayer, on these maps:
Heretic
Longshore
Citadel
Assembly
Orbital
Sandbox
Gold Skulls, found in campaign:
Iron
Black Eye
Tough Luck
Catch
Fog
Thunderstorm
Tilt
Mythic
Silver Skulls
Blind
Grunt Birthday
Cowbell
I Would Have Been Your Daddy
The main use for the skulls is to use during the campaign when trying to get more points. If you set up a campaign lobby and press the' X ' button you have the option to turn them on. Once al skills are turned on then you will get alot more points during the game but the skulls will cause odd things to happen like you shields don't re generate and as nath said u have t start the level from scratch if u die.
They are mainly used in this way to get the achievements via xbox live
Source(s):Have the game and collected all silver skullsthe remains of a dead person's decomposed head
1.Iron 2.Black Eye 3.Tough Luck 4.Catch 5.fog 6.Famine 7.Thunderstorm 8.Tilt 9.Mythic 10. Blind 11.Cowbell 12.grunt birthday party 13.iwhbyd
you can get all of the skulls on multiplayer. =)
if you want to know where the skulls are all you have to do is go to youtube and put in "halo 3 odst mythic skulls" and it will show you how to get to them
ok, go to youtube and type in "how to find all halo 3 skulls" then watch the video and get the skulls. yes, its that simple.
By getting skulls.
get all skulls
Find them your self
Go to Halopedian.com. They have the largest source of everything Halo.
If i am correct then it is the same as the skulls being off.
archon armor
THey get you an achievement, and they get you the Hayabusa helmet.
All skulls are automatically unlocked for Halo 3: ODST due to gameplay reasons.
Sorry there arn't any, The only skulls are in "Halo 3" Which are used in "Halo 3 O.D.S.T."