yes you can well in multiplayer anyway
No, in Halo 2 you can not unlock armor.
There is two ways to get it #1 unlock all of the armor #2 is to become the highest rank in halo reach
You unlock the armor.
You unlock the odst armor by unlocking the UNSC SPARTAN achievement
You have to be an warrant officer in halo reach to unlock the helmet you also have to go to halowaypoint and unlock the armor.
go to http://hubpages.com/hub/Halo-3-Armor
To unlock Recon armor in Halo 3, you originally had to beat all of the VidMaster achievments, but the armor is now available to all players. To unlock the recon armor in Halo: Reach you had to pre-order the game and you would get a long (25 character) code for the recon armor DLC. To unlock the recon armor in Halo 4, you had to either pre-order the game or simply buy the armor with your in-game credits.
you have to get 49+ acheivments
Lucky for you, there is now a way to easily unlock recon armor. There are a few steps you must complete to unlock Recon armor in Halo 3. 1. Buy Halo 3: ODST 2. Create a bungie account. 3. Complete the vidmaster achievements on Halo 3 and Halo 3: ODST. There are 7 in all. 4. Under your account preferences, click Unlock Recon. You should now have recon armor. RUB IT IN THEIR FACES!!!
yes you still unlock the armor. you and the player that your playing with unlock the armor. =] =) =p q=].
you buy it and you can unlock some by halo waypoint (free download)
Halo Reach armor is sold with a credit system which you earn credits in the game itself by playing. Halo 3 armor you must unlock with achievements and completing certain aspects of the game.