Strike!
Kill 5 enemies with a single grenade in Single Player or Special Ops. I highly recommend to try this challenge on Special Ops Survival. Sometimes you get it just by luck, but here you're able to try it yourself. This is pretty simple, if you own the third DLC of MW3. Just start up the chaosmode on Dome, fight for about one minute, so that many enemies arrive, then throw a stun-grenade on the ground and quickly after that a regular frag-grenade. This should take out about 10 enemies at once.

Jack the Ripper
Melee 5 enemies in a row in Single Player or Special Ops.

Back in the Fight
Start the Single Player Campaign on any difficulty. No doubt, this is the easiest of all achievements.

Who Dares Wins
Just finish the game - no matter what difficulty you've chosen.


The Best of the Best
Complete the campaign on Hardened or Veteran difficulty. I recommend to play the campaign on Veteran because of the Veteran-Level-Achievements.

Informant
Collect 22 Intel Items hidden in the MW3-Campaign. Here's a guide which tells you the position of all the intel. Unfortunately, the author is Russian and the guide, too, but it's a video and the intel-positions don't change with countrys ;)

Scout Leader
Collect 46 Intel Items. This means, you have to find EVERY Intel Item hidden in the MW3-Campaign. Here's a guide which tells you the position of all the intel. Unfortunately, the author is Russian and the guide, too, but it's a video and the intel-positions don't change with countrys ;)

Too Big to Fail
Destroy the Jamming Tower. Complete "Black Tuesday" on any difficulty.


This Is My Boomstick
Kill 30 enemies with the XM25 in "Black Tuesday." Just spray around ;)




Wet Work
Take back New York Harbor. Complete "Hunter Killer" on any difficulty.


The Big Apple
Complete "Black Tuesday" and "Hunter Killer" on Veteran difficulty.




Carpe Diem
Escape the mountain safe house. Complete "Persona Non Grata" on any difficulty.


What Goes Up...
Destroy all the choppers with only the UGV's grenade launcher in "Persona Non Grata."




Frequent Flyer
Defend the Russian President. Complete "Turbulence" on any difficulty.


Flight Attendant
Kill all 5 enemies during the zero-g sequence in "Turbulence."




Up to No Good
Infiltrate the village. Complete "Back on the Grid" on any difficulty.


Out of the Frying Pan...
Complete "Persona Non Grata", "Turbulence", and "Back on the Grid" on Veteran difficulty.


For Whom the Shell Tolls
Destroy all targets during the mortar sequence with only 4 shells in "Back on the Grid."




One Way Ticket
Make it to Westminster. Complete "Mind the Gap" on any difficulty.




Welcome to WW3
Save the US Vice President. Complete "Goalpost" on any difficulty.




Sandstorm!
Assault the shipping company. Complete "Return to Sender" on any difficulty.


Payback
Complete "Mind the Gap", "Goalpost", and "Return to Sender" on Veteran difficulty.


Kill Box
Kill 20 enemies with the Chopper Gunner in a single run in "Return to Sender."




Back Seat Driver
Track down Volk. Complete "Bag and Drag" on any difficulty.


Danger Close
Take down a chopper with an AC-130 smoke grenade in "Bag and Drag."




We'll Always Have Paris
Escape Paris with Volk. Complete "Iron Lady" on any difficulty.


City of Lights
Complete "Bag and Drag" and "Iron Lady" on Veteran difficulty.


Ménage à Trois
Destroy 3 tanks with a single 105mm shot in "Iron Lady."




Vive la Révolution!
Reach the church. Complete "Eye of the Storm" on any difficulty.




Requiem
Escape the city. Complete "Blood Brothers" on any difficulty.




Storm the Castle
Discover Makarov's next move. Complete "Stronghold" on any difficulty.


The Darkest Hour
Complete "Eye of the Storm", "Blood Brothers", and "Stronghold" on Veteran difficulty.




Bad First Date
Find the girl. Complete "Scorched Earth" on any difficulty.


Nein
Kill 9 enemies with A-10 strafing runs in "Scorched Earth."




Diamond in the Rough
Rescue the Russian President. Complete "Down the Rabbit Hole" on any difficulty.




This is the End
Complete "Scorched Earth", "Down the Rabbit Hole", and "Dust to Dust" on Veteran difficulty.

Brag Rags
Earn one star in Special Ops Mission Mode. Just finish any mission to get this achievement, DLC-Maps do not count towards this achievement!

Overachiever
Earn 48 stars in Special Ops Mission Mode. That means, that you have to finish every mission on Veteran. DLC-Maps do not count towards this achievement!

Tactician
Earn one star in each mission of Special Ops Mission Mode. Just play every map and get your stars. DLC-Maps do not count towards this achievement!

50/50
Complete a Special Ops Mission Mode game with the same number of kills as your partner.


No Assistance Required
Complete a Special Ops Mission Mode game on Hardened or Veteran with no player getting downed. It is possible to finish this in Solo-Mode. Just finish any map on Hardened or Veteran with no coop-Player (or just don't get downed when playing online).

Serrated Edge
Finish a Juggernaut with a knife in Special Ops. This is quite difficult and you will need a lot of attempts to get this achievement. It's always helpful to throw a grenade at the juggernaut without downing him. Then shoot about three times at his head and try your luck. This achievement is also available on Special Ops Survival - please note, that it's double-listed in this guide.

Slippery Slope
Complete the "Black Ice" Special Ops mission on any difficulty.


Ice in Your Veins
Complete the "Black Ice" Special Ops mission on Veteran difficulty.


A Baker's Dozen
Kill 13 enemies with the snowmobile in the "Black Ice" Special Ops mission by overrunning them.



Shotgun Diplomacy
Complete the Special Ops mission "Negotiator" on any difficulty.


Skilled Negotiator
Complete the Special Ops mission "Negotiator" on Veteran difficulty.


Not on My Watch
Rescue all the hostages in the Special Ops mission "Negotiator."



Kill Switch

One-Four-One
Complete the "Kill Switch" Special Ops mission on any difficulty.


EMPressive…
Complete the "Kill Switch" Special Ops mission on Veteran difficulty.


Helipocalypse
Destroy 6 helicopters in the "Kill Switch" Special Ops mission.




Don't Tread on Me
Complete the "Iron Clad" Special Ops mission on any difficulty.


High Roller
Complete the "Iron Clad" Special Ops mission on Veteran difficulty.


Not a Scratch
Finish with your tank at full health in the "Iron Clad" Special Ops mission.




Stay Frosty
Complete the "Arctic Recon" Special Ops mission on any difficulty.


Sub Zero
Complete the "Arctic Recon" Special Ops mission on Veteran difficulty.


dr0n3d
Complete the "Arctic Recon" Special Ops mission in under 3:30.




Apex
Complete the "Vertigo" Special Ops mission on any difficulty.


Pinnacle
Complete the "Vertigo" Special Ops mission on Veteran difficulty.


Flyswatter
Destroy all helicopters in the "Vertigo" Special Ops mission. There are 16 of them.


To Jugger or to Jugger-Naut
Kill all juggernauts AFTER they have landed on Veteran difficulty in the "Vertigo" Special Ops mission. Note: There are several RPGs around you, keep that in mind when it comes to juggernauts :P



Siege
Complete the "Light 'Em Up" Special Ops mission on any difficulty.


Lights Out
Complete the "Light 'Em Up" Special Ops mission on Veteran difficulty.


Deer in the Headlights
Stab five stunned enemies in a row in the "Light 'Em Up" Special Ops mission.




Handle with Care
Complete the "Special Delivery" Special Ops mission on any difficulty.


Deliver This
Complete the "Special Delivery" Special Ops mission on Veteran difficulty.


Untouchable
Use only one self revive care package in the "Special Delivery" Special Ops mission.


Discriminating Buyer
Use exactly one of each care package in the "Special Delivery" Special Ops mission.

I Live
Survive one wave on any Special Ops Survival map. DLC-Maps do not count towards this achievement!

Survivor
Reach Wave 10 in each and every mission of Special Ops Survival mode. DLC-Maps do not count towards this achievement!

Unstoppable
Reach Wave 15 in each and every mission of Special Ops Survival mode. DLC-Maps do not count towards this achievement!

Birdie
Kill two enemy helicopters without getting hit on any Special Ops Survival map.


Serrated Edge
Finish a Juggernaut with a knife in Special Ops. This is quite difficult and you will need a lot of attempts to get this achievement. It's always helpful to throw a grenade at the juggernaut without downing him. Then shoot about three times at his head and try your luck. This achievement is also available on Special Ops Mission Mode - please note, that it's double-listed in this guide.

Get Rich or Die Trying
Own $50,000 on any Special Ops Survival map.


Arms Dealer
Buy each and every item from the Survival Weapon Armory.


Danger Zone
Buy each and every item from the Survival Air Support Armory.


Defense Spending
Buy each and every item from the Survival Equipment Armory.

Please remember to RATE and FAVORITE :]