Full list of all 82 Gears of War 3 achievements worth 2,000 gamerscore. It takes around 1000 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 7 DLC packs containing 32 achievements worth 1,000 Gamerscore.
Earned the Onyx "War Supporter" medal.
Reached level 50.
Recovered all 42 Collectibles.
Recovered all 15 COG Tags.
Earned an Onyx medal.
Recovered 20 of 42 Collectibles.
Completed 5 Arcade Campaign chapters in co-op.
Executed your enemies with variety and style.
Your respect for the dead earned you access to Griffin's special weapons stash.
Wreaked vengence upon humanity!
Completed one match in all six Versus multiplayer modes.
Survived all 50 waves of Horde.
Earned the Bronze "Loot Courtesan" medal.
Reached level 25.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Reached level 15.
Killed 10 enemies in Team Deathmatch.
Survived the first 10 waves of Horde.
Reached level 10.
Completed the first 12 waves of Beast.
Completed all campaign Acts on Casual or Normal Difficulty.
Killed Myrrah.
Rescued Adam Fenix from captivity.
Turned off the Maelstrom device.
Passed under the Maelstrom and found Azura.
Launched the sub.
Found enough fuel to get to Endeavor naval base.
Found and activated the fuel pump.
Recovered 5 of 42 Collectibles.
Drove from Anvil Gate to Mercy.
Defeated the Lambent Berserker.
Defended Anvil Gate from the Locust siege.
Arrived safely, kinda, at Anvil Gate.
Grabbed a Locust Gas Barge to travel to Anvil Gate.
Discovered the location of Adam Fenix.
Blew up the Lambent Leviathan from the bridge.
Reached level 5.
Executed an infected player and is now turning Lambent.
Defended and escaped from Cougar Stadium.
Found food and ammo in Hanover.
Defended the Raven's Nest from Lambent Leviathan.
Woke up from a bad dream.
Your skill and experience means you’re ready for Standard Versus multiplayer.
Complete all campaign Acts on Hardcore Difficulty (Standard or Arcade).
Complete all campaign Acts on Insane Difficulty (Standard or Arcade).
Complete all Campaign Acts in Co-op (any difficulty, Standard or Arcade).
Complete all Campaign Acts in 4 player Co-op (any difficulty, Standard or Arcade).
Earn the Bronze "Force Multiplier" medal.
Earn the Silver "Number 1" medal.
Reach level 100 and earn every Onyx medal.
Found new places to destroy all humans.
Showed your friends the Horde Command Pack sights.
We are the elite Onyx Guard!
Good ROI on that Silverback upgrade.
The Hammer of Dawn is now online!
Ignored all Loader safety guidelines and killed 10 Locusts.
Honored the memory of Zeta Squad in 10 matches of Versus.
Completed "RAAM's Shadow" in Arcade Campaign.
Showed 50 Locusts the meaning of sky-fire with HOD Command Center.
Completed "RAAM's Shadow" in Standard Campaign.
As RAAM, ripped 50 Gears to shreds with your Kryll.
Complete "RAAM's Shadow" in 4 player co-op in either Arcade or Standard mode.
As Mauler, kill 10 Gears by reflecting their bullets using your shield.
As RAAM, execute Minh 10 times in Versus MP (Standard or Casual).
Defeated the first 10 waves of Horde with every member of Zeta in your party.
Completed all 50 waves of Horde on any of the Fenix Rising maps.
Won a Versus multiplayer match as a team of five Recruit Claytons (any mode).
Won a Versus multiplayer match as a team of five Savage Marauders (any mode).
Completed all 12 waves of Beast on all Fenix Rising maps.
Achieve level 100 and choose to re-up for another tour of duty.
Achieve level 100 a second time and choose to re-up for another tour.
Earned all 132 combat ribbons.
Cleaved 25 enemies with a hidden weapon.
Maxed out all of the Horde fortifications.
Guardian is back!
Completed all 12 waves of Beast on all Forces of Nature maps.
Completed all 50 waves of Horde on any of the Forces of Nature maps.
The $!*@# was taken down with extreme force.
Still standing after 20 waves - you're a natural!
Found the right man for the job!
Captured and "released" 20 opponents as the Savage Hunter.
Kill 10 opponents as the leader in a round of Guardian on a Forces of Nature map.