Diablo – How to Get Cooperative Achievements in D3

You do not need every single XBL achievement in order to get 100% completion in Red Dead Redemption. You need to do the following:

• Complete all 57 story missions
• Purchase all 5 rare weapons
• Do the 3 Nightwatch jobs and 2 Horsebreaking jobs at least once
• Unlock all 9 Outfits
• Purchase all 13 player houses
• Complete all 7 gang hideouts
• Complete 20 bounties, doesn't matter if you kill or capture. You need 8 in New Austin, 8 in Mexico, and 4 in West Elizabeth.
• Win at all 6 minigames at least once
• Discover all 94 map locations
• Complete all ranks of Survivalist, Treasure Hunter, Master Hunter, and Sharpshooter challenges (rank I and II)
• Complete 18 Stranger missions (though the I Know You one doesn't count towards this, as it is potentially missable)

If you're signed up on Rockstar's Social Club website, it keeps track of what you've completed, which I've found to be a great help. It's kind of slow in keeping synched though, but it's awesome for reference.

Getting all of the Co-op achievements turns into a pretty boring grindfest once you know how go do it.

To get all achievement in fewest games as possible you should play as Random vs. Insane AI, because - like Sorean mentioned - it counts for lower AIs. Also try to do the each race combination vs. 3 Insane AI and 15 Win-streak vs. 3 Insane AI first, because after that you only need to play vs. 2 AI where the games end quicker.

Beating Insane is not hard if you use basic rush strategies for each race:

Zerg

• 6 Pool
• 10 Pool + Gas with Speedlings
• Inbase Spinecralwer if up against at least 1 Zerg
• skip Zerglings and go for Mutalisks from 2 Bases - this is only safe if your allies distract all enemies so they do not overwhelm you before Mutas are out

Protoss

• Cannon-Rush with 1st Pylon and Forge as Proxy
• transition into mass Proxygate Zealots if up against Zerg (creep is so annoying for cannonrushing)
• for very long games maybe get Void Rays

Terran

• 3 proxy Barracks with mass Reaper - fastest for killing worker and buildings - consider to get +1 Attack for more efficency in later game stages (if it occurs)
• Proxy Barracks and mass Marines - get some bunkers too if you don't have uber micro (so get them almost always)

Also make sure to distract the AI with a Extractor/Pylon/Engeneering Bay in his base. This way the computer will pull workers from mining and try to kill your building. Make sure they lose as much mining time as possible and have less stuff to hold your rush off. When your units come out, go for their harvesters first if its possible, but do not sacrifice too much of your army.

Obviously getting some friends in to have a relying team will make the win-streak much easier than getting random people that might fail and deny your achievement after 14 successful games.