Bromageddon

Completed the Campaign cooperatively on Heroic or harder.

The Legend of 117

Completed the Campaign on Legendary difficulty.

I Need a Hero

Completed the Campaign on Heroic or harder.

Bropocalypse

Completed any Campaign mission cooperatively on Heroic or harder.

What a Poser!

Changed your Spartan's pose in the Spartan ID card.

Movin' On Up

Ranked up your Spartan-IV to SR-20.

Hanging on the Combat Deck

Won 20 War Games matchmaking matches.

Pitchin' a Tent

In matchmaking, effectively camped one location without dying for a full 60 seconds.

I <3 Red vs Blue

Won 5 War Games matchmaking matches.

Badge

Changed your Emblem in the Spartan ID card.

Armorer

Changed your Spartan's armor in the Spartan Armor card.

The Challenged

Completed a Challenge.

PWND

Changed your Service Tag in the Spartan ID card.

Not Some Recruit Anymore

Ranked up your Spartan-IV to SR-5.

Wake Up, John

Completed the Campaign on Normal or harder.

Midnight

Completed mission 8 on any difficulty.

Composer

Completed mission 7 on any difficulty.

Shutdown

Completed mission 6 on any difficulty.

Reclaimer

Completed mission 5 on any difficulty.

Infinity

Completed mission 4 on any difficulty.

Forerunner

Completed mission 3 on any difficulty.

Requiem

Completed mission 2 on any difficulty.

Contact the Domain

Found a Terminal in the Campaign.

Dawn

Completed mission 1 on any difficulty.

Digging up the Past

Found and accessed Chief's record in mission 1.