Unlock the following Spartan armor permutations by fulfilling the requirement listed…

• EOD (Body) – Complete Tsavo Highway (on Legendary)
• EOD (Head) – Complete the campaign mode (on Legendary)
• EOD (Shoulders) – Complete The Ark (on Legendary)
• EVA (Body) – Complete Tsavo Highway (on Normal, Heroic, or Legendary)
• EVA (Head) – Complete the campaign mode (on Normal)
• EVA (Shoulders) – Complete The Ark (on Normal, Heroic, or Legendary)
• Mark V (Head) – Get the UNSC Spartan Achievement
• ODST (Head) – Get the Spartan Graduate Achievement
• Rogue (Head) – Get the Spartan Officer Achievement
• Scout (Body) – Get the Too Close to the Sun Achievement
• Scout (Head) – Get the Used Car Salesman Achievement
• Scout (Shoulders) – Get the We’re in for Some Chop Achievement
• Security (Head) – Get 1,000 Gamerscore Points
• Security (Shoulders) – Get 750 Gamerscore Points

Unlock the following Elite armor permutations by fulfilling the requirement listed…

• Ascetic (Body) – Get the Up Close and Personal Achievement
• Ascetic (Head) – Get the Steppin’ Razor Achievement
• Ascetic (Shoulders) – Get the Overkill Achievement
• Commando (Body) – Get the Triple Kill Achievement
• Commando (Head) – Get the Overkill Achievement
• Commando (Shoulders) – Get the Killing Frenzy Achivement
• Flight (Body) – Complete Tsavo Highway (on Heroic or Legendary)
• Flight (Head) – Complete the campaign mode (on Legendary or Heroic)
• Flight (Shoulders) – Complete The Ark (on Heroic or Legendary)

Unlockable: Gold Skull Locations

• Black Eye (Located: Crow’s Nest)

When activated, you will have to battle enemies with melee tactics to regain shield energy.

• Catch (Located: The Storm)

When activated, enemies will throw more grenades.

• Famine (Located: The Ark)

When activated, dropped weapons will hold less ammunition.

• Fog (Located: Floodgate)

When activated, the motion tracker disappears.

• Iron (Located: Sierra 117)

When activated, you will be sent back to the beginning of the stage you’re on when you die instead of to the last checkpoint.

• Mythic (Located: Halo)

When activated, all enemies will have twice as much health.

• Thunderstorm (Located: The Covenant)

When activated, enemies will be of a higher rank.

• Tilt (Located: Cortana)

When activated, enemies will become more resilient to your attacks.

• Tough Luck (Located: Tsavo Highway)

When activated, enemies are skilled at getting away from projectiles such as grenades.