Some helmets on Halo 3 require you to get to a certain rank on online multiplayer, some require you to complete the campaign on certain difficulties (including legendary, but you can do this on solo or co-op), some require certain achievements and others require you to collect all the skulls. I would know as I have obtained all, hope that helps, look on YouTube for more info or guides.
Also I will list the helmets for both Spartans and elites and give info on how to get them.
Spartans: Mark VI (already unlocked), Mark V (get UNSC spartan achievement), ODST (get spartan graduate achievement), CQB (already unlocked), Hayabusa (collect all skulls in campaign), EVA (complete campaign on normal or higher), Security (obtain 1000G on Halo 3), Recon (complete all vidmaster achievements), Rogue (get spartan officer achievement), Scout (get used car salesman achievement), EOD (complete campaign on legendary)
Elites: Commando (get overkill achievement), Aesthetic (get steppin razor
achievement), Flight (complete campaign on Heroic or higher), Assault (already unlocked) , Combat (already unlocked)
No you cannot buy halo 3 helmets in the game... but you can buy nerdy plastic helmets at like Gamestop...
Well there are a couple of ways to get the helmets: 1. Playing the campaign (depends on the difficulty) 2. Earning achievements 3. Getting a certain amount of gamer score 4. You can get Recon from Halo 3: ODST Hope that helps!!
go on youtube and type in search halo3 skull and it will tell you where all the skulls are.
All I know is that it's a Halo3 Xbox LIVE clan.
You have to get all achievements 100%
To get the recon armor you have to complete all the vidmaster achievements in halo3 and halo3 odst.
by playing all levels succesfully.
you have to go to halo3 mods .com on google and click on halo3 how to mod
fun is dodo
Their isn't any cheats for Halo3
in my opinion halo 3odst
all helmets are