Note: Story-related achievements are self-explanatory and can't be missed so they won't contain much detail.
Another Day in the Corps! (20G)
Bad Feeling About This Drop (20G)
Complete Sulaco Falls
Quoth the Raven (20G)
Complete The Raven
Still Got a Job to Do (20G)
Just a Grunt (20G)
Complete Hope in Hadley's
Dragged Queen (20G)
Game Over, Man! (30G)
Complete all Campaign levels on any difficulty
Not Bad For a Human (40G)
Complete all Campaign levels on Hardened difficulty
Refer to State of Badass Art for more details.
State of the Badass Art (50G)
Complete all Campaign levels on Ultimate Badass difficulty
This will be a lot manageable by playing in co-op. Aside from enemies being tougher and can deal greater damage, your HUD will also be disabled in this mode. Also, you may want to attempt this on the second playthrough so your rank is already high and you're already able to purchase upgrades to your weapons.
Oorah to Ashes (10G)
Collect a dog tag.
Refer to this guide's Dog Tags locations section for the exact locations of all dog tags in the game.
Remember the Fallen (30G)
Collect all 35 Dog Tags
Refer to this guide's Dog Tags locations section for the exact locations of all dog tags in the game. For co-op games, players must individually collect the dog tags for it to count in their progress.
Personal Friend of Mine (10G)
Collect a legendary weapon.
Refer to the Legendary Weapons section of this guide.
I Like to Keep These Handy (30G)
Collect all 6 Legendary Weapons
I Heard THAT (25G)
Collect all 12 Audio Logs
Refer to this guide's Audio Logs section to know the locations of each Audio Log
Short, Controlled Bursts (20G)
Defeat all Xenomorphs in the Sulaco hangar bay without them crossing your barricade
Halfway in Mission 1: Distress, you'll have to keep the xenomorphs from crossing the barricade until Keyes successfully opens the door.
Fire Drill (20G)
Arm the emergency release and escape in under 2:30 on Sulaco Falls
Once you've reached the dropship, you'll have to arm the emergency release to complete the mission. Take the stairs in the corner to arm the first release control terminal. Continue along the catwalk and head to the other side where the next emergency release control terminal is located. The catwalk will collapse so head back and clear the control room. Activate the crane and wait for it to establish a new walkway for you. Head to the next terminal and activate it. Once done, jump back to the floor and get on the ramp of the dropship.
Mostly Come at Night... (20G)
Find Newt's doll
This is found in the sewer area in Mission 5: The Raven, where you have to navigate it unarmed. Once you turned on the first sewage pump, the blind xenos will get attracted to it and explode. Continue along the path and look for an alcove to the right, where there are barrels. The doll's head should be there.
Heavy Lifting (20G)
Defeat the Raven in under 1:10 on Soldier difficulty or higher
Near the end of the mission, you'll have to control the powerloader to combat the Raven. You have to punch it using LT and RT. Unfortunately, this powered suit is not very quick so it can be a challenge to finish this battle quickly.
No Need For Alarm (20G)
Complete One Bullet without setting off the alarm
As you're navigating different laboratories in the mission, scientists will attempt to run towards the highlighted alarm buttons on the walls. You can do this on Recruit difficulty so you can easily kill the scientists. Use of shotguns and explosives is also recommended.
Another Bug Hunt (5G)
Complete 1 challenge.
Refer to “Distinguished Service Medal”
Stay Frosty (20G)
Complete 1 challenge category.
Refer to “Distinguished Service Medal”
Distinguished Service Medal (30G)
Complete all Challenges
There are 86 challenges, which grant 500xp each when completed. Each category features an Active Challenge which gives you three challenges available at a given time. Using legendary weapons may not be counted towards challenges so you may opt using the basic weapons
Field Modified: Purchase a Marine weapon upgrade
Spray N' Pray: Kill 5 enemies with hip fire
Two For One: Kill two enemies with one shot from an Underslung Grenade Launcher
Boom Stick: Kill 20 enemies using the Pump Shotguns primary fire
Big ******* Signal: Track 5 xenos at once on your Motion Tracker
Heavily Armed: Kill 7 enemies using a primary weapons alternate fire
Kill Or Be Killed: Kill 20 enemies with any rifles primary fire
Straight Shooter: Get 1o headshots using the Service Pistol
Airtime: Kill 20 enemies that are climbing on the walls or ceiling
Pop Goes The Melon: Get 10 headshots on xenos with any rifle
Short, Controlled Bursts: Do not miss an enemy with any bullets from a full rifle mag
Sharp Shooter: Kill 20 enemies that are 15m away or farther, using the Battle Rifle
Trapper: Kill 20 enemies with Battle Rifle Mines
Second To None: Kill 15 enemies with any side arm
Carry A Big Stick: Kill 3 enemies with a primary weapons alternate fire without dying
Back On Your Feet: Revive 5 other players in Coop Campaign or Versus Matches
Equal Opportunity: Kill 20 enemies using the Combat Pistol
Set Em Up, Knock Em Down: Kill 10 enemies with Claymores, Mine Launcher Mines or Acid Traps
Spread The Love: Kill 2 enemies within 10 seconds using the SMG
Xenophobia: Kill 10 Soldier, 10 Lurker or 10 Spitter xenos
Blown To Hell: Kill 20 enemies using the Assault Rifles Grenade Launcher
Make It Count: Shoot enemies with an entire clip using the Service Pistol without missing or reloading
Down But Not Out: Kill an enemy while incapacitated
Amateur Surgeon: Decapitate a xenomorph
Flash Fire: Kill 2 enemies with fire damage within 10 seconds
Judge, Jury And Executioner: Execute 20 enemies using the Pulse Rifles primary fire
Shotty Workmanship: Kill 20 enemies using the Tactical Shotguns primary fire
Keep Up The Fire: Kill 6 enemies in under 60 seconds using the SMG
Reflex Action: Kill 5 xenomorphs that are inside a vent using the Pump Shotgun
The Silent Killer: Kill 5 enemies using a suppressor on the Battle Rifle
Amputation: Remove 20 limbs from xenos using the Tactical Shotgun
Stand Your Ground: Make the killing shot on a crusher using the Service Pistol
Combined Arms: Use the Combat Pistol to kill 10 enemies that were on fire
Feel The Burn: Kill 20 enemies using firebombs
Assault With Intent: Kill 20 enemies using the Assault Rifles primary fire
Light Em Up: Kill 20 enemies using the Assault Rifles Underslung Flamethrower
Shock Trooper: Kill 20 enemies that were stunned using the Tactical Shotguns Arc Rounds
Solid Legs: Complete a campaign mission on any difficulty
Splattered: Gib 5 enemies in a single campaign mission
Better Than Harsh Language: Kill 5 enemies with melee in a single campaign mission
Nice Groupings: Kill 2 enemies with a single shot from the Pump Shotgun
Tactical Supremacy: Kill 6 enemies with Tactical weapons in a campaign mission
Double Tap: Kill 2 enemies that are stunned in a campaign mission
Bug Hunter: Kill 5 facehuggers
Sawbones: Remove a total of 20 limbs from xenomorphs
Iron Fist: Kill 10 enemies with melee in a single campaign mission without dying
Superior Firepower: Kill 2 enemies with the Smart Gun, Flamethrower or RPG in a campaign mission
Inside Out: Kill 5 enemies with explosives in a campaign mission
Battle Hardened: Complete a campaign mission on Hardened or higher difficulty
Ultimate Badass: Complete a campaign mission on Ultimate Badass
Mutation: Purchase a Xeno combat upgrade
Eggstermination: Win an Extermination mode match
Survivalist: Win a Survivor mode match
Escape Artist: Win an Escape mode match
Victorious: Kill 25 enemies in Team Death Match
Hard To Kill: Completed an Escape Match without being incapacitated
Hard Boiled: Kill 5 Xeno Boilers during a multiplayer match
Uncrushable: Kill 5 Xeno Crushers during a multiplayer match
Raking Claws: Kill 10 enemies with Quick Strike as a soldier xeno
Blunt Force: Kill 10 enemies with Heavy Strike as a soldier xeno
Berserker: Kill 10 enemies with Flurry as a soldier xeno
Sliced And Diced: Kill 2 enemies with a single Whirlwind attack as a soldier xeno
Free Hugs: Kill 20 enemies using the Pounce attack as a soldier xeno
Easy Prey: Kill an enemy after stunning them with Bludgeon as a soldier xeno
Spit In Your Eye: Kill 10 enemies with Acid Spit as a spitter xeno
Ricochet: Kill 10 enemies with Acid Rebound as a spitter xeno
Stepped In It: Kill 5 enemies with Acid Trap as a spitter xeno
Hawked It All Up: Kill 2 enemies at once with a single fully charged Spit attack as a spitter xeno
Left A Mark: Kill 10 enemies with Acid Strike as a spitter xeno
Acid Bath: Kill 10 enemies with Rupture Mutation as a spitter xeno
Cat-Like Reflexes: Pounce on three enemies in less than 10 seconds as a lurker xeno
Kill Em While They're Down: Kill an enemy after knocking them down with Speed Pounce as a lurker xeno
Shock And Awe: Kill 2 enemies with a single Shockwave Pounce attack as a lurker xeno
Extended Reach: Kill 5 enemies using Lunging Strike as a lurker xeno
Flurry Finish: Kill an enemy with Flurry after a Speed Pounce as a lurker xeno
From The Shadows: Kill 5 enemies without taking any damage as a lurker xeno
Heads Up: Kill an enemy from the wall or ceiling as a xeno
Sentry Duty: Destroy 5 Sentry turrets
Two Birds: Kill two enemies with one shotgun blast
Scout: Track 50 Xenos on the Motion Tracker
Fire In The Hole: Kill 25 Xenos using the Smart Gun, Flamethrower or RPG
Liquefy: Kill 8 enemies with acid damage
Mercy Killer: Use the Combat Pistol to kill 5 enemies that were covered in fire
Trap Sprung: Kill 25 Xenos using Claymore mines
Alpha: Kill 5 Marines without dying
Ace: Kill 5 Xenos without dying
Field Promotion (10G)
Reach Rank 2 as a marine.
Refer to “I Love the Corps!”
Lean and Mean (20G)
Reach Rank 20 as a marine.
Refer to “I Love the Corps!”
I Love the Corps! (40G)
Earn Rank 60 as a Marine
You can earn experience from kills, collectibles, challenges, match bonuses and completing campaign missions. For campaign missions, the higher the difficulty, the higher exp is awarded. One good way to farm exp is by replaying the last campaign mission, Home. This is easier done in co-op; one will distract the queen while the other runs for the switches.
Ready to Fry Half a City (5G)
Edit a Marine Loadout
Once you've unlocked new weapons and equipment, select Versus from the main menu then “Edit Loadouts” and “Marine Loadouts”.
Field Modified, Kill Certified (20G)
Upgrade every slot for a weapon
Take note that skins do count towards the slots of a weapon. The pistols have lesser slots though you should remember that some skins can only be unlocked after completing certain challenges.
I Can Handle Myself (40G)
Purchase all Upgrades for a weapon
Pistols are still the quickest way to unlock this achievement. You don't have to upgrade the skins as they don't count for this achievement.
Majority Shareholder (25G)
Spend 30 Commendations
When you rank up, you obtain one commendation that you can use to purchase upgrades for your weapon. You should be around LV31 to unlock this achievement.
You Look Just Like I Feel (30G)
Upgrade every Appearance slot once for your Marine
From the main menu, access “Versus” > “Edit Apperance” > “Marine Appearance”. You have to make changes to every category. New appearance items are unlocked by completing challenges.
Structural Perfection (5G)
Edit a Xenomorph Loadout
From the main menu, access “Versus” > “Edit Loadouts” > “Xeno Loadouts”. Modify your loadout once you have new skills available.
Perfect Killing Machine (20G)
Upgrade every Loadout slot for a Xenomorph class
From the main menu, access “Versus” > “Edit Loadouts” > “Xeno Loadouts”. You should be able to get this at rank 7 by concentrating on either lurker or spitter classes.
Adaptive Morphology (30G)
Upgrade every Appearance slot once for a Xenomorph class
From the main menu, access “Versus” > “Edit Apperance” > “Xeno Appearance”. You have to make changes to every category. New head and skins are unlocked by completing challenges.
I Feel Safer Already (10G)
Have another player join your party
This achievement will pop as soon as another player joins your game. If you have another profile and controller, power on the controller and sign it in another profile to unlock this achievement.
Don't Count Me Out (5G)
Revive a teammate
During co-op campaign, an downed player will be on the ground with a pistol. Get near them and press X to revive them.
Micro Changes in Air Density (10G)
Track 100 hostile targets with the Motion Tracker
Whenever you hear a “blimp” and the radar icon appears in the lower-middle part of your screen, open your motion tracker to track targets.
Eat This! (10G)
Kill a Xenomorph with a shotgun at very close range
You can time your shot when a soldier xeno gets up close and attempts to melee you. Hitting it with your own melee attack and stunning it before killing it will also count.
Adios, Muchachos (20G)
Gib two enemies at once
This only works on xenos. You have to kill two xenos using one shot from your Pulse Rifle's grenade launcher (secondary/ alternate fire) This is easily done by letting xenos converge on your allies.
It's a Dry Heat (20G)
Kill 3 enemies with a single U4 Firebomb
The firebomb is unlocked automatically after reaching Rank 4. To equip it, press Y to open the weapon radial then select Tactical, then highlight the firebomb before releasing Y. It will be easier to do this to xenomorphs since they're aggressive. Let them converge on your allies then throw a firebomb in the middle. You have to kill three xenos with one firebomb to unlock the achievement.
Entry Prohibited (20G)
Kill 10 Xenomorphs that are using vents
These are openings found on ceilings, railings, and floors. Just shoot them as soon as they appear.
Coming Outta the Walls! (10G)
Kill a Xenomorph climbing on the walls or ceiling
Let's Rock! (20G)
Kill 10 Xenomorphs in a game with the M56A2 Smart Gun
You'll have the Smart Gun equipped as part of Mission 4: No Hope in Hadley's. You'll reach a corridor full of xenos. Just let them have it and you'll unlock this achievement in no time.
Need a Deck Of Cards? (5G)
Set up a UA 571-C Remote Sentry
This is easily unlocked as part of the objective in Mission 4: No Hope in Hadley's where you need to get the sentry gun and place it in operations.
Arbitrarily Exterminated (30G)
Kill 2179 Xenomorphs
Refer to “Let's Rock!” achievement details. In the same hallway, you can keep restarting the checkpoint to keep your kills and score and to replenish your ammo.
Anytime, Anywhere (20G)
Kill a Crusher without it damaging you
As soon as the gate opens, exit a bit but don't get too far ahead. Find the slope in the left corner of the gate, beside the corpse. This is where you'll make the stand. Now go ahead to make the crusher appear. Wait for it to get near then return to the high ground you found earlier and stay there. When done correctly, the crusher will just walk towards you or stay still while you're laying fire on it. Use explosives and grenades to take it out. There are other slopes or elevated spots in the areas but this is nearest one and possibly won't trigger xeno respawns.
Secreted from What? (20G)
5 Spitters without being damaged by acid
In Mission 6: For Bella, you'll come across a cavern with glowing lights on the walls. These are spitters. Just stay at a distance and use your Battle Rifle to take them out from afar. Kill 5 and the achievement will unlock.
No Offense (20G)
Melee a Lurker that is pouncing towards you
Lurkers are tougher, faster and enemies that will most likely catch you offguard. It is best to have a shotgun equipped when attempting this. You'll encounter three of these near the end of Mission 4: No Hope in Hadley's. You can attempt this for the first two lurkers. If you still haven't unlocked the achievement, restart the checkpoint before killing the third one.
Love at First Sight (10G)
Survive a Close Encounter with a Facehugger
There's a sequence in Mission 1: Distress where a facehugger will jump to your face. Just press X to shove it away and unlock this achievement.
But No Cigar (20G)
Rescue a teammate from a Close Encounter
For a co-op mission, watch out when your partner is pinned by a xeno or facehugger. Shoot it point blank with a shotgun preferably, to unlock this achievement.
Easter Egg (5G)
Find the Easter Egg
Available in Mission 2. You have to find a keypad on the infested walls in a corner to open a door containing a creepy room with decorated eggs. Refer to the video below for more details.
[video=A_easter.mp4 title= Easter Egg