Get a 4 kill long kill streak. Get a double kill. Get the first kill in a match.

Kill 10 people.

Rescued a groupmate from death in a co-op game

Mastered the technology of Pandora

Applied an elemental artifact

Killed 25 enemies with explosive weapons

Emerged victorious from an arena match

Won a duel against another player

Equipped a class mod for your character

Defeated the Rakk Hive, the Vault Boss, Sledge, Krom, or Flynt in a co-op game

Sold 50 guns to a shop

Collect all other Trophies