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