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.
Earned the Silver "Number 1" medal.
Completed all campaign Acts on Insane Difficulty.
Completed all campaign Acts on Hardcore Difficulty.
Complete all Acts in 4 player Co-op on any difficulty.
Earned the Bronze "Force Multiplier" medal.
Passed under the Maelstrom and found Azura.
Turned off the Maelstrom device.
Rescued Adam Fenix from captivity.
Killed Myrrah.
Completed all campaign Acts on Casual or Normal Difficulty.
Complete all Acts in Co-op on any difficulty.
Survived all 50 waves of Horde.
Recovered all 15 COG Tags.
Recovered all 42 Collectibles.
Completed 5 Arcade Campaign chapters in co-op.
Woke up from a bad dream.
Defended the Raven's Nest from Lambent Leviathan.
Found food and ammo in Hanover.
Defended and escaped from Cougar Stadium.
Blew up the Lambent Leviathan from the bridge.
Discovered the location of Adam Fenix.
Grabbed a Locust Gas Barge to travel to Anvil Gate.
Drove from Anvil Gate to Mercy.
Found and activated the fuel pump.
Found enough fuel to get to Endeavor naval base.
Launched the sub.
Recovered 5 of 42 Collectibles.
Arrived safely, kinda, at Anvil Gate.
Defended Anvil Gate from the Locust siege.
Defeated the Lambent Berserker.
Your respect for the dead earned you access to Griffin's special weapons stash.
Recovered 20 of 42 Collectibles.
Earned an Onyx medal.
Reached level 50.
Earned the Bronze "Loot Courtesan" medal.
Executed your enemies with variety and style.
Survived the first 10 waves of Horde.
Completed one match in all six Versus multiplayer modes.
Reached level 25.
Wreaked vengence upon humanity!
Reached level 15.
Executed an infected player and is now turning Lambent.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Reached level 10.
Reached level 5.
Killed 10 enemies in Team Deathmatch.
Completed the first 12 waves of Beast.
Your skill and experience means you’re ready for Standard Versus multiplayer.
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!
As RAAM, made sure Minh never forgets that day outside the House of Sovereigns.
Ignored all Loader safety guidelines and killed 10 Locusts.
Showed 50 Locusts the meaning of sky-fire with HOD Command Center.
Honored the memory of Zeta Squad in 10 matches of Versus.
Completed "RAAM's Shadow" in Standard Campaign.
Completed "RAAM's Shadow" in 4 player co-op.
Completed "RAAM's Shadow" in Arcade Campaign.
Used the Mauler shield to kill 10 Gears that had the temerity to fire upon you and your General.
As RAAM, ripped 50 Gears to shreds with your Kryll.
Defeated the first 10 waves of Horde with every member of Zeta in your party.
Level 100 - so nice, I did it twice.
Completed all 50 waves of Horde on any of the Fenix Rising maps.
Completed all 12 waves of Beast on all 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).
Level 100 and going back for more!
Earned all 132 combat ribbons.
Completed all 50 waves of Horde on any of the Forces of Nature maps.
Still standing after 20 waves - you're a natural!
Led by example and killed 10 opponents as Guardian leader.
Cleaved 25 enemies with a hidden weapon.
Completed all 12 waves of Beast on all Forces of Nature maps.
Captured and "released" 20 opponents as the Savage Hunter.
The $!*@# was taken down with extreme force.
Found the right man for the job!
Guardian is back!
Maxed out all of the Horde fortifications.