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.
Reached level 50.
Completed all campaign Acts on Hardcore Difficulty.
Completed all campaign Acts on Insane Difficulty.
Completed one match in all six Versus multiplayer modes.
Recovered all 42 Collectibles.
Recovered all 15 COG Tags.
Complete all Acts in 4 player Co-op on any difficulty.
Complete all Acts in Co-op on any difficulty.
Your respect for the dead earned you access to Griffin's special weapons stash.
Earned an Onyx medal.
Completed 5 Arcade Campaign chapters in co-op.
Completed all campaign Acts on Casual or Normal Difficulty.
Killed Myrrah.
Rescued Adam Fenix from captivity.
Executed your enemies with variety and style.
Turned off the Maelstrom device.
Passed under the Maelstrom and found Azura.
Launched the sub.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Reached level 25.
Executed an infected player and is now turning Lambent.
Killed 10 enemies in Team Deathmatch.
Wreaked vengence upon humanity!
Completed the first 12 waves of Beast.
Found enough fuel to get to Endeavor naval base.
Found and activated the fuel pump.
Drove from Anvil Gate to Mercy.
Defeated the Lambent Berserker.
Defended Anvil Gate from the Locust siege.
Arrived safely, kinda, at Anvil Gate.
Recovered 20 of 42 Collectibles.
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.
Recovered 5 of 42 Collectibles.
Reached level 15.
Survived all 50 waves of Horde.
Survived the first 10 waves of Horde.
Reached level 10.
Earned the Bronze "Loot Courtesan" medal.
Reached level 5.
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.
Earn the Bronze "Force Multiplier" 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!
Get 500 Silverback rocket kills in Horde (any map, any difficulty).
Achieve Level 4 in Horde Command Center fortifications.
Showed 50 Locusts the meaning of sky-fire with HOD Command Center.
Completed "RAAM's Shadow" in Standard Campaign.
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.
As Mauler, kill 10 Gears by reflecting their bullets using your shield.
Using the Loader, kill 10 Locust.
Play 10 matches of Versus as a member of Zeta (Barrick, Tai, Minh, or Valera)(Standard or Casual).
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 12 waves of Beast on all 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 50 waves of Horde on any of the 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.
Earn at least one of each of the original 132 combat ribbons.
Complete all 12 waves of Beast on all Forces of Nature maps.
Complete 20 consecutive waves of Horde on any Forces of Nature map without going down or dying.
Complete all 50 waves of Horde on any of the Forces of Nature maps.
Get 25 kills with any of the hidden elementally charged Cleavers in Horde.
Achieve the maximum level on all fortifications in Horde mode.
Win a match of Guardian on all Forces of Nature maps.
Build or repair 50,000 worth of fortifications as Mechanic Baird LE.
Bag and Tag 20 opponents while playing as the Savage Hunter in Versus multiplayer (any mode).
Kill 10 opponents as the leader in a round of Guardian on a Forces of Nature map.
Kill a Lambent Berserker with a team comprised of 5 Forces of Nature characters in Horde.