Successfully complete one of the following tasks to get a trophy:

  Tutorials Completed (Bronze): Complete the tutorial for each character. 
  First Blood (Bronze): Try to be the first one that kills an enemy in challenge 
  mode. 
  Ability First Kill (Bronze): Perform a kill using your ability for the first 
  time in a challenge. 
  Challenges Master (Bronze): Win Death Match without being killed in a 
  challenge. 
  Ability Master (Bronze): Perform 10 frags in a row with only your abilities in 
  challenge mode. 
  BlackOp Campaign Completed (Bronze): Complete all challenges in the BlackOp 
  Campaign. 
  Bishop Campaign Completed (Bronze): Complete all challenges in the Bishop 
  Campaign. 
  Guardian Campaign Completed (Bronze): Complete all challenges in the Guardian 
  Campaign. 
  Arena Master (Silver): Perform 5 kills without being killed in a ranked match. 
  Slayer (Silver): Get 100 kills in ranked matches. 
  All Rewards Unlocked (Silver): Unlock all Rewards. 
  Marathon (Gold): Score 1,000,000 points.