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.
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.
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.
Completed all campaign Acts on Hardcore Difficulty.
Recovered 5 of 42 Collectibles.
Recovered 20 of 42 Collectibles.
Reached level 5.
Executed your enemies with variety and style.
Wreaked vengence upon humanity!
Earned the Bronze "Force Multiplier" medal.
Earned the Silver "Number 1" medal.
Survived the first 10 waves of Horde.
Your skill and experience means you’re ready for Standard Versus multiplayer.
Earned the Onyx "War Supporter" medal.
Reached level 50.
Complete all Acts in 4 player Co-op on any difficulty.
Complete all Acts in Co-op on any difficulty.
Completed all campaign Acts on Insane Difficulty.
Earned an Onyx medal.
Survived all 50 waves of Horde.
Completed 5 Arcade Campaign chapters in co-op.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Reached level 25.
Earned the Bronze "Loot Courtesan" medal.
Completed the first 12 waves of Beast.
Reached level 15.
Reached level 10.
Completed one match in all six Versus multiplayer modes.
Executed an infected player and is now turning Lambent.
Killed 10 enemies in Team Deathmatch.
Recover all 42 Campaign Collectibles (any difficulty, Standard or Arcade).
Recover all 15 COG Tags during the Campaign (any difficulty, Standard or Arcade).
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, ripped 50 Gears to shreds with your Kryll.
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.
Complete "RAAM's Shadow" in Standard Campaign on any difficulty.
Using the Hammer of Dawn Command Center, kill 50 Locust.
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 50 waves of Horde on any of the Fenix Rising maps.
Complete all 12 waves of Beast on all Fenix Rising maps.
Win a Versus multiplayer match as a team of five Recruit Claytons (any mode).
Win a Versus multiplayer match as a team of five Savage Marauders (any mode).
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.
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!
Maxed out all of the Horde fortifications.
Complete all 12 waves of Beast on all Forces of Nature maps.
Get 25 kills with any of the hidden elementally charged Cleavers in Horde.
Win a match of Guardian on all Forces of Nature maps.
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.