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.
Earned the Bronze "Force Multiplier" medal.
Reached level 50.
Survived all 50 waves of Horde.
Earned the Bronze "Loot Courtesan" 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 an Onyx medal.
Survived the first 10 waves of Horde.
Your respect for the dead earned you access to Griffin's special weapons stash.
Wreaked vengence upon humanity!
Completed the first 12 waves of Beast.
Executed your enemies with variety and style.
Recovered all 42 Collectibles.
Recovered all 15 COG Tags.
Recovered 20 of 42 Collectibles.
Completed 5 Arcade Campaign chapters in co-op.
Completed one match in all six Versus multiplayer modes.
Reached level 25.
Killed 10 enemies in Team Deathmatch.
Reached level 15.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Reached level 10.
Executed an infected player and is now turning Lambent.
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.
Reached level 5.
Found and activated the fuel pump.
Drove from Anvil Gate to Mercy.
Defeated the Lambent Berserker.
Defended Anvil Gate from the Locust siege.
Recovered 5 of 42 Collectibles.
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.
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.
Reach level 100 and earn every Onyx medal.
Showed your friends the Horde Command Pack sights.
We are the elite Onyx Guard!
Found new places to destroy all humans.
Good ROI on that Silverback upgrade.
The Hammer of Dawn is now online!
Used the Mauler shield to kill 10 Gears that had the temerity to fire upon you and your General.
As RAAM, made sure Minh never forgets that day outside the House of Sovereigns.
Honored the memory of Zeta Squad in 10 matches of Versus.
Ignored all Loader safety guidelines and killed 10 Locusts.
Showed 50 Locusts the meaning of sky-fire with HOD Command Center.
Completed "RAAM's Shadow" in Arcade Campaign.
Completed "RAAM's Shadow" in 4 player co-op.
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.
Completed all 50 waves of Horde on any of the Fenix Rising maps.
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.
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.
The $!*@# was taken down with extreme force.
Completed all 50 waves of Horde on any of the Forces of Nature maps.
Guardian is back!
Captured and "released" 20 opponents as the Savage Hunter.
Cleaved 25 enemies with a hidden weapon.
Completed all 12 waves of Beast on all Forces of Nature maps.
Still standing after 20 waves - you're a natural!
Found the right man for the job!
Achieve the maximum level on all fortifications in Horde mode.
Kill 10 opponents as the leader in a round of Guardian on a Forces of Nature map.