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.
Completed all campaign Acts on Insane Difficulty.
Completed 5 Arcade Campaign chapters in co-op.
Complete all Acts in Co-op on any difficulty.
Recovered all 42 Collectibles.
Recovered all 15 COG Tags.
Your respect for the dead earned you access to Griffin's special weapons stash.
Executed your enemies with variety and style.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Recovered 20 of 42 Collectibles.
Killed 10 enemies in Team Deathmatch.
Completed one match in all six Versus multiplayer modes.
Reached level 50.
Executed an infected player and is now turning Lambent.
Earned the Bronze "Loot Courtesan" medal.
Survived all 50 waves of Horde.
Reached level 25.
Wreaked vengence upon humanity!
Completed the first 12 waves of Beast.
Survived the first 10 waves of Horde.
Earned the Onyx "War Supporter" medal.
Earned an Onyx medal.
Reached level 15.
Reached level 10.
Completed all campaign Acts on Casual or Normal Difficulty.
Completed all campaign Acts on Hardcore 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.
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.
Grabbed a Locust Gas Barge to travel to Anvil Gate.
Reached level 5.
Recovered 5 of 42 Collectibles.
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.
Complete all Campaign Acts in 4 player Co-op (any difficulty, Standard or Arcade).
Earn the Bronze "Force Multiplier" medal.
Earn the Silver "Number 1" medal.
Reach level 100 and earn every Onyx medal.
Host a private Horde Match with a party of 5 players on any Horde Command Pack map (any difficulty).
Host a private Beast Match with a party of 5 players on any Horde Command Pack map (any difficulty).
Defeat a Boss Wave as 5 Onyx Guards (Hardcore difficulty).
Good ROI on that Silverback upgrade.
The Hammer of Dawn is now online!
Completed "RAAM's Shadow" in 4 player co-op.
Completed "RAAM's Shadow" in Arcade Campaign.
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.
As RAAM, ripped 50 Gears to shreds with your Kryll.
Honored the memory of Zeta Squad in 10 matches of Versus.
As Mauler, kill 10 Gears by reflecting their bullets using your shield.
As RAAM, execute Minh 10 times in Versus MP (Standard or Casual).
Complete waves 1-10 of Horde with 5 players as Zeta (Barrick, Tai, Minh, Valera and Jace).
Completed all 50 waves of Horde on any of the Fenix Rising maps.
Level 100 and going back for more!
Completed 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 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.
Maxed out all of the Horde fortifications.
Still standing after 20 waves - you're a natural!
Cleaved 25 enemies with a hidden weapon.
Captured and "released" 20 opponents as the Savage Hunter.
Completed all 12 waves of Beast on all Forces of Nature maps.
Found the right man for the job!
Win a match of Guardian on all Forces of Nature maps.
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.