10 All According to Plan...Kill all the enemies in the first encounter of 'Truth and Reconciliation' without being detected.
10 BeachheadStorm the beach of 'The Silent Cartographer' with no marine casualties on Heroic or Legendary.
10 Birth of a SpartanComplete every level of the game on Normal difficulty.
10 Look Out for the Little GuysComplete the level 'Two Betrayals' on Heroic difficulty or higher without killing any Grunts.
10 Looks like the OddballFind your first campaign skull.
10 No-Fly ZoneDestroy three of the four Banshees on 'Halo' on any difficulty during a single play-through.
10 Overshields are for SissiesComplete the level 'Pillar of Autumn' on Legendary without picking up an Overshield.
10 Standard Operating BrocedureComplete any level on Normal difficulty cooperatively.
10 That Just HappenedComplete the level 'The Library' on Heroic difficulty or higher without dying.
10 This One's for Jenkins!Kill 50 Flood Combat Forms on the level '343 Guilty Spark' on Heroic difficulty or higher.
10 This Side UpComplete the Warthog ride on the level 'The Maw' without being forcibly ejected from your vehicle.
10 Tying Up Loose EndsKill every Elite on the level 'Keyes' on Heroic difficulty or above.
10 What have we here?Read a terminal.
10 Wraith HunterDestroy four Wraith tanks in 'Assault on the Control Room' with the Scorpion tank, in a single play.
20 Believe in a HeroComplete every level of the game on Heroic difficulty.
20 BrovershieldComplete any level on Heroic difficulty cooperatively.
20 He’s Unstoppable!Complete any level on Heroic difficulty or higher without taking health damage.
25 343 Guilty SparkComplete the level '343 Guilty Spark' on any difficulty.
25 Assault on the Control RoomComplete the level 'Assault on the Control Room' on any difficulty.
25 Breaking QuarantineEscape the Forerunner facility on the level '343 Guilty Spark' in 21 minutes or less.
25 Close Quarters CombatComplete the level 'Truth and Reconciliation' with at least four rounds left in your Sniper Rifle.
25 GrenadierEscape the map room in 'The Silent Cartographer' without firing a shot on Heroic or Legendary. (6)
25 HaloComplete the level 'Halo' on any difficulty.
25 Heavy ReadingRead half the terminals hidden throughout the campaign.
25 How PedestrianComplete the level 'Halo' on any difficulty without entering a vehicle.
25 I’ll Be Taking That!Pilot a Banshee on the level 'Assault on the Control Room.'
25 KeyesComplete the level 'Keyes' on any difficulty.
25 Leave It Where It LayComplete the level 'Two Betrayals' on Legendary difficulty without picking up a new weapon.
25 Never Tell Me the OddsEscape 'The Maw' on Legendary with at least a minute left on the count down.
25 Pillar of AutumnComplete the level 'Pillar of Autumn' on any difficulty.
25 Popcorn.gifKill 100 Flood Infection Forms on the level 'Keyes' on Heroic difficulty or above.
25 Skulls Taken!Locate half of the skulls hidden throughout the campaign.
25 Speed ReaderComplete the level The Library on Legendary difficulty in 30 minutes or less.
25 The LibraryComplete the level The Library on any difficulty.
25 The MawComplete the level The Maw on any difficulty.
25 The Silent CartographerComplete the level The Silent Cartographer on any difficulty.
25 Truth and ReconciliationComplete the level Truth and Reconciliation on any difficulty.
25 Two BetrayalsComplete the level Two Betrayals on any difficulty.
25 Walk it OffComplete the level Pillar of Autumn on Legendary without picking up a health kit.
50 Bro HammerComplete any level on Legendary difficulty cooperatively.
50 Dear Diary...Read all of the terminals hidden throughout the campaign.
50 HeadhunterLocate all the skulls hidden throughout the campaign.
50 Living LegendComplete every level of the game on Legendary difficulty.
50 TsantsaComplete any level with at least three skulls active on Heroic difficulty or higher.