Instructions
Complete the game campaign on the "Normal," "Heroic" or "Legendary" difficulty setting to unlock the Spartan EVA mask. Complete the campaign on "Herioc" or "Legendary" to unlock the Elite Flight mask. Complete the "Legendary" campaign to unlock the Spartan EOD mask.
Earn 1000 Gamerpoints to unlock the Spartan Security mask. Gamerpoints are achieved by performing specific in-game tasks.
Unlock achievements of skill in the game. The "Used Car Salesman" achievement -- making three fully-manned enemy vehicle kills in either the Campaign mode or multiplayer-ranked mode -- unlocks the Spartan Scout mask. Earn the "Overkill" achievement -- kill four players within 4 seconds of each prior kill -- to unlock the Elite Commando mask. Use the energy sword in a multiplayer-ranked Free-For-All match and score a "Triple Kill" -- kill three players within 4 seconds of each prior kill -- to earn the "Steppin' Razor" achievement that unlocks the Elite Ascetic mask.
Play the online-multiplayer mode and earn experience and rank. Earn five experience points by winning games or complete 10 ranked matches to earn the "Spartan Graduate" achievement, which will unlock the Spartan ODST mask. Reach the Sergeant rank to unlock the Spartan Mark V mask. Advance to the Spartan Officer rank of 1st Lieutenant or better to unlock the Spartan Rogue mask.
Collect all 12 gold and silver skulls in campaign mode to earn the "Hyabusa" mask variant. The Hyabusa, commonly known as the "Samurai" variant, is not normally visible from the armor variant page at the console. The twelve skulls are hidden in the levels of the game and some require intricate steps for you to retrieve them.