- We Few, We Happy Few...
Complete all Acts in 4 player Co-op on any difficulty.
14 April 2012 - 4 guides
- Ain't My First Rodeo
Completed all campaign Acts on Hardcore Difficulty.
14 April 2012 - 3 guides
- That's Just Crazy
Completed all campaign Acts on Insane Difficulty.
14 April 2012 - 17 guides
- Socialite
Earned the Onyx "War Supporter" medal.
13 April 2012 - 8 guides
- Hoarder
Recovered all 42 Collectibles.
17 March 2012 - 9 guides
- Remember the Fallen
Recovered all 15 COG Tags.
17 March 2012 - 8 guides
- Welcome to Arcade Mode
Completed 5 Arcade Campaign chapters in co-op.
- Award Winning Tactics
Earned an Onyx medal.
03 March 2012 - 8 guides
- Judge, Jury and Executioner
Executed your enemies with variety and style.
29 December 2011 - 4 guides
- Enriched and Fortified
Survived all 50 waves of Horde.
17 December 2011 - 4 guides
- It's All About the Loot!
Earned the Bronze "Loot Courtesan" medal.
17 December 2011 - 2 guides
- Level 50
Reached level 50.
13 December 2011 - 4 guides
- Ready for More
Completed all campaign Acts on Casual or Normal Difficulty.
26 October 2011 - 3 guides
- My Fellow Gears
Complete all Acts in Co-op on any difficulty.
26 October 2011 - 2 guides
- You're Dead! Now Stay Dead!
Killed Myrrah.
26 October 2011 - 2 guides
- Ok. Faith. Yeah. Got It.
Rescued Adam Fenix from captivity.
- Look at That, Instant Summer.
Turned off the Maelstrom device.
- Pack Rat
Recovered 20 of 42 Collectibles.
26 October 2011 - 3 guides
- Welcome To -redacted-
Passed under the Maelstrom and found Azura.
- Baird's Favorite Kind of Toy
Launched the sub.
- Think You Can Handle That?
Found enough fuel to get to Endeavor naval base.
- Respect for the Dead
Your respect for the dead earned you access to Griffin's special weapons stash.
21 October 2011 - 6 guides
- The Versus Sampler Platter
Completed one match in all six Versus multiplayer modes.
12 October 2011 - 3 guides
- Brothers to the End
Found and activated the fuel pump.
25 September 2011 - 2 guides
- Lost Your Good Driver Discount
Drove from Anvil Gate to Mercy.
- Was it Good For You?
Defeated the Lambent Berserker.
25 September 2011 - 2 guides
- Anvil Gate's Last Resort
Defended Anvil Gate from the Locust siege.
25 September 2011 - 2 guides
- Thanks For Flying GasBag Airways
Arrived safely, kinda, at Anvil Gate.
25 September 2011 - 2 guides
- Oh Yeah, It's Pirate Time
Grabbed a Locust Gas Barge to travel to Anvil Gate.
- Welcome to Horde Mode
Survived the first 10 waves of Horde.
25 September 2011 - 2 guides
- Wreaking Locust Vengence
Wreaked vengence upon humanity!
25 September 2011 - 4 guides
- Level 25
Reached level 25.
23 September 2011 - 2 guides
- Okay, Now We Find Hoffman
Discovered the location of Adam Fenix.
21 September 2011 - 2 guides
- Welcome to Beast Mode
Completed the first 12 waves of Beast.
- Putting it Scientifically…
Blew up the Lambent Leviathan from the bridge.
20 September 2011 - 2 guides
- My Turf! Cougars Territory!
Defended and escaped from Cougar Stadium.
- Collector
Recovered 5 of 42 Collectibles.
20 September 2011 - 2 guides
- We Struck Gold, Son!
Found food and ammo in Hanover.
- Swimmin' in Glowie Gravy
Defended the Raven's Nest from Lambent Leviathan.
20 September 2011 - 2 guides
- Marcus, It's Your Father
Woke up from a bad dream.
20 September 2011 - 2 guides
- Level 15
Reached level 15.
20 September 2011 - 2 guides
- Wait, What Time is it?
Maxed the Consecutive Match Bonus in Versus multiplayer.
20 September 2011 - 3 guides
- Level 10
Reached level 10.
20 September 2011 - 3 guides
- Lambency
Executed an infected player and is now turning Lambent.
20 September 2011 - 6 guides
- Level 5
Reached level 5.
20 September 2011 - 2 guides
- Welcome to Versus
Killed 10 enemies in Team Deathmatch.
20 September 2011 - 4 guides
- Welcome to the Big Leagues
Your skill and experience means you’re ready for Standard Versus multiplayer.
20 September 2011 - 3 guides
- All for One, One for All
Earn the Bronze "Force Multiplier" medal.
Locked - 15 guides
- First Among Equals
Earn the Silver "Number 1" medal.
Locked - 2 guides
- Seriously 3.0
Reach level 100 and earn every Onyx medal.
Locked - 23 guides