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