This guide will help any achievement-hunters get 100% of the Steam/Origin achievements for the game, will help you play a generally completionist game, and will be almost entirely spoiler-free. If you want to get 100% of the achievements in one playthrough, I recommend you read at least the next section before starting.

This guide will assume you do the bare minimum of multiplayer. My understanding is that the achievements which can be acquired in either are generally easier in singleplayer (with the possible exception of Medic! and Terminator), but if you want to do the multiplayer, more power to you.

It is possible to get 100% of the achievements in a single playthrough. To do so, you must play on Insanity. Additionally, it is easier if you play as the male Ryder—otherwise, you'll have to reload some saves. There are very few strictly missable achievements: Unwavering (beat on Insanity) Cryptographer (Remnant key decryption), Friendly Fire (Remnant VI use), and Matchmaker (romance 3 people).

General considerations: Do everything you want and can before doing the final story mission (The one where you return to the Remnant city.). It will be quite clear in terms of story narrative when the final mission is, and you are given a warning that the mission on which you are embarking will conclude the main story. You can do some side quests afterward, but some will be impossible to complete, and others will no longer effect how the final mission goes. Anything involving the Hyperion will be harder/impossible to finish.

Thus, complete side quests and your companions' loyalty missions before doing the final story mission.

See the point on Matchmaker to learn how to do that on one playthrough.

Speak to your squadmates between story missions and after their loyalty missions. You will get fun dialogue, but, more importantly, their loyalty missions and, less importantly, other side quests, like Movie Night.

Additionally, try to go for the combat achievements systematically early in the game. They will help you figure out your preferred play style, even if you've played Mass Effect games before. I found myself liking the tech powers after some experimentation.

Finally, have fun, explore the world! While not necessary for 100% achievements, speaking to everyone and enjoying the story and Heleus Cluster will be fun and let you experience all of the quests.

You will get all of the following achievements without going out of your way whatsoever:

• First Contact
  
• Pathfinder
  
• Initiated
  
• World-Shaper
  
• Foothold
  
• First Steps
  
• Full Roster
  
• Exaltation
  
• Liberation
  
• Activation
  
• Family Connections
  
• Mission Accomplished

The following achievements are hard to miss assuming you do any of the side quests. I will indicate which ones in spoiler tags, but, seriously, you shouldn't need these if you read quest descriptions (or even achievement descriptions):

• Role Model: Cora's loyalty mission, just talk to her occasionally and you'll get it
  
• Helping Hand: Vetra's loyalty mission
  
• Alliance: Do the quests on Kadara to increase its viability
  
• Buccaneer: Drack's loyalty mission
  
• Building Bridges: Jaal's loyalty mission
  
• United: Liam's loyalty mission
  
• Signal Tracking: Peebee's loyalty mission

These achievements are pretty self-explanatory and hard to miss if you know what you're doing:

• Almost There: To hit level 25, just do quests (side and main). You'll hit it easily.
  
• Peak Condition: Like the above, but only to level 40. I was over 60 when I finished my first playthrough.
  
• Data Mining: Just scan things using your scanner (down on the d-pad when playing with an Xbox-style controller). You'll want to do this to get research data and complete some missions anyway.
  
• Craftsmanship: Most medium-level guns and armor will have 3 augmentation slots. Very easy to get if you do any crafting.
  
• Kitted Out: Just kill any enemy with a Rank 5 weapon. Easy unless you rush through the story and stop playing.
  
• Unwavering: For this, you have to select Insanity when you create your character (can be done on New Game+), and keep it on until you finish the story. Self-explanatory. If you want to get all the achievements on one playthrough, you have to start on Insanity. I found doing it on NG+ fairly easy.

To get these achievements, you will need to increase viability on all 5 main planets to 100%. This can be done through completing story missions, side missions, tasks, and reactivating their vaults. I recommend starting with the latter, as reactivating the vaults generally makes the planets easier to navigate (it makes Elaaden, the scorching moon, less hot, for example):

• Terraformer
  
• All Clear

These are all of the combat-related achievements. None of them are especially hard once you consciously go for them, and some you will get basically by playing the game.

• Pinpoint Shot: Simply hit enemies in their weak spots (heads for humanoids, glowing parts for Remnant enemies).
  
• With Our Powers Combined: Many squadmates will prime a target for detonation, all you then have to do is use a power that triggers combo detonations (e.g., Concussive Shot) on them. Peebee is a good choice for this because when her targets are primed they're floating—an obvious visual indicator.
  
• Fireworks: Simply prime and then detonate combos. You will do this if you are paying any attention while playing, and you'll make a lot of progress while attempting to get the other achievements.
  
• Terminator: Kill 2,000 enemies. This may sound like a lot but I got this before finishing my first playthrough. You don't need to go out of your way to get this if you're going for the side missions—unless you hang back and let your squad do all the work!
  
• Close Combat Specialist: Simply kill enemies with melee attacks.
  
• Mastermind: Your Remnant VI or Auto Turret, both in the Tech skills, need to kill 100 enemies. You'll use the Remnant VI for another achievement anyway.
  
• Trapshooter: Hit floating enemies (that you made float or that Peebee is making float) with Concussive Shot (Combat), Lance (Biotic), or Incinerate (Tech).
  
• Death from Above: Just hover (use the aim button while you're in the air) and kill enemies while hovering. Easier said then done, but not especially difficult.
  
• Medic!: Revive your teammates 25 times. Even on Insanity, my teammates weren't going down often enough for this. On Elaaden, there is an area in the downed Remnant ship with a ton of Turrets. You can direct your squadmates into their line of fire, hunker down, and revive them afterward. A messy but effective way to get this achievement on any difficulty.
  
• Icebreaker: Freeze an enemy (with Cryo Ammo or one of the many skills that freezes them), then jump up and melee to shatter them. Will take a few tries but not too hard.
  
• Pyrotechnics Expert: Put at least one point into Flamethrower (more will make this easier), get surrounded by a few enemies, and let them have it!
  
• Vanguard Surprise: Put one point into Tactical Cloak (Tech), one point into Charge (Biotic), and then use one and then the other. Not that hard.
  
• Fastball: Put points into Pull (Biotic), and hold it down while using it. You'll be holding an enemy. Now, simply aim them at another enemy, and use Throw (Biotic) to chuck them. This one is fun.
  
• Sucker Punch: This one is best done by putting a bunch of points into Singularity (Biotic), and then running up and hitting the enemies as they float there.
  
• Rough Landing: This is like Fastball, but instead of throwing them into another enemy, throw them into a Trip Mine (Combat) you've placed. Moderately annoying to get.

This is a missable achievement involving the Remnant VI. To get it, you have to do a couple missions for Peebee. Once you have it, direct it to target each of the types of Remnant. You direct it by tapping whatever button you used to summon it while aiming at whatever you want it to target.

You have to make it attack:

• Assembler
  
• Breacher
  
• Observer
  
• Nullifier
  
• Destroyer (both the body and the turret
  
• Architect*

*There are only 4 Architects. I believe you only need to have it target the leg, but you may have to make it target the head conduits as well. Eos, Voeld, Kadara, and Elaaden each have one. There is also one in the final mission, but you can only target its head. Don't kill the other 4 without getting this achievement unless you plan on going through again!

You get the following achievements through adjusting your profile (Vanguard, Tactician, etc.) and skills. Some of these you will get through experimenting with the other achievements or simply by playing.

• Jack Of All Trades: See guide for High Performance
  
• Full Power: Simply max out one skill each in Tech, Combat, and Biotics—I don't know if this needs to be done at once but you'll get it doing High Performance
  
• High Performance: Okay, simply get level 6 in each profile type. Easy, right? Actually, yes. If you want to save money, save either right before or right after you respec (using the terminal in the Tempest's medbay), and then invest your points wisely. You will need at least level 46 to have enough points to get it.
  
  • Soldier: All (232+) in Combat
    
  • Engineer: All (232+) in Tech (including the Remnant VI power)
    
  • Adept: All (232+) in Biotics
    
  • Sentinel: Half in Tech and Biotics (116+ each)
    
  • Vanguard: Half in Combat and Biotics (116+ each)
    
  • Infiltrator: Half in Combat and Tech (116+ each)
    
  • Explorer: One third in each (78+).
  Make sure you actually activate each profile before reloading your save.

These are pretty easy to get provided you check your APEX terminal periodically. It can be used on the Nexus in the militia HQ (near Kandros), or on the Tempest. Speak to Kandros if you need the rundown. I also got the APEX HQ app for my phone, which allowed me to check the results of missions while I wasn't playing and send teams out.

• Explorer: You'll get this just from sending your APEX teams out a few times.
  
• Veteran: Send your teams out a few more times. You'll get this before you get the other ones.
  
• Top Talent: Just keep sending a team out on successful missions to level it up. 20 is the max level. Don't send it out on missions you know it'll fail too often—sometimes they can get negative traits that lower their effectiveness permanently. I recommend not checking the results of missions when the team is level 19 while in the APEX HQ smartphone app—if it hits level 20 it may not count toward the Steam achievement. Wait until you are in-game.
  
• Teamwork: Recruit six strike teams. Simply spend your mission currency on more strike teams whenever you can, keep sending them out on missions they're likely to be successful on, etc. See my warning above about the app.
  
• APEX: Simply complete the multiplayer tutorial mission. This is the only achievement which can only be obtained in multiplayer, but you don't actually play with anyone to get it.

To get this achievement, you need to romance 3 characters across all playthroughs. Ryder can romance the following characters based on the player character's sex:

Male Ryder:

• Cora, Gil, Avela

Female Ryder:

• Liam, Suvi

Either Ryder:

• Peebee, Jaal, Vetra, Reyes, Keri

To romance a character, be sure to pick the flirt option (the heart) whenever you can. Additionally, to consummate the romance, you will need to progress to a certain point in the story and/or complete their loyalty mission (the latter for Peebee, Cora, Liam, Jaal, Vetra).

To obtain on a single playthrough without save manipulation, you have to be a male Ryder and romance Keri, Avela, and a squadmate. Once you lock in with a squadmate you will be unable to flirt with most other characters, so do not speak to a squadmate after their loyalty mission unless you are ready to commit. To use this method, get the angaran artifacts for Avela and then speak to her. Then, complete the story mission up until the end and speak with Keri. Then, do a squadmember's loyalty mission and then complete the romance with them.

Alternately, you can save before "completing" the romance, then reload afterward. My understanding is that this will count.

Of note is that I actually had to do 4 romances before I got this: I romanced Peebee, then Avela (this may not have counted as I had locked in with Peebee already). Then in my next playthrough I romanced Suvi (then reloaded the save), but didn't get the achievement. Then I romanced Keri and got it. If you'll do at least two playthroughs this should be fairly easy so long as you don't lock in early.

This is a missable achievement. You need to unlock 20 of the Remnant sudoku-like puzzles. However, there are only 22 per playthrough, and 6 of them are missable. Of these, 5 are in the vaults on each planet (once you activate the vault, it becomes sealed), and one is in the penultimate story mission (when you first visit the Remnant city).

There is some confusion online as to whether they always count and whether using a Remnant Decryption Key (possible on most of them), will count toward the achievement. I used a key once and unlocked the achievement, I believe, on my 20th puzzle. To be safe, I recommend solving the puzzles manually or looking up the solutions online.

A brief guide to the various puzzle locations, with minimal spoilers:

Eos

• Story-related
  
• Vault (missable)
  
• Task: Data Trail
  
• Task: The Ghost of Promise

Voeld

• Peebee's Secret Project
  
• 1st monolith
  
• 2nd monolith
  
• 3rd monolith
  
• Vault (missable)
  
• Task: Subjugation

Havarl

• Helping Havarl's Scientists
  
• Vault (missable)
  
• Free roam

Kadara

• Monolith
  
• Vault (missable)

Elaaden

• Monolith
  
• Vault (missable)
  
• Investigate the Remnant Derelict
  
• Task: Cache Flow
  
• Free roam

H-047C

• The Remnant Tiller

Khi Tasira

• The Journey to Meridian (missable)

For Hang Time, you need to make a super-long jump in the Nomad. You don't even need to land it! This is only possible on H-047C, and is best done with Nomad upgrades to your jump-jets and boost. To get this, you need to go to the western edge of the long east-west chasm. There should be a little hill. Jump off it and make sure to use your jump jets as you can and your boost periodically. It is necessary to angle the Nomad up (easier on controller). I found this video guide useful:

For this one, you need to jump 30m and survive. I needed to try a few times—sometimes you don't jump far enough, sometimes you jump far enough but die. This video explains it at least as well as I can:

Now you have 100% of the achievements (or will after completing the last story mission), and you want to know what else there is. There are side missions scattered throughout the cluster, most of which are hard to miss. Only some of them (those associated with the Hyperion are inaccessible after beating the story mission. Either way I recommend finishing all side quests before finishing the story.

A special shout-out to Task: Remnant Data Cores, the one mission I believe I didn't finish. The Mass Effect Wiki has a relatively low-spoiler guide[masseffect.fandom.com] to where the data cores are. Note that there are 11 of them but several are missable, meaning that you need to be deliberate if you want to get his one. In particular, each Architect drops a chest right beneath it when you defeat it. Open this up to get a data core. For some reason I missed a few of these the first time around.

Lastly, the final story mission is affected by the side missions that you do. I recommend doing all of them before doing the mission. You have more allies help you—I am not sure if it makes it actually easier or just narratively easier. In addition, if you want Captain Dunn to survive, you must recruit all three of the other Pathfinders. This means finding the salarian ark (unmissable story), asari ark (Cora's loyalty mission), and the turian ark (obvious side quest). Moreover, you have to convince Avitus to become the turian Pathfinder, so that he appears at the end of the game.

I hope this guide has been helpful. Please leave any feedback in the comments and let me know if this helped you get an achievement or plan your playthrough, or if you have any ideas on how to improve this guide. Good luck!