A Beginner’s Guide To The World Of Mass Effect

A Beginner’s Guide To The World Of Mass Effect
Image: Kotaku

With the Mass Effect Legendary remaster out today, it’s time for everyone to dive back into the treasure trove of jargon, lore, backstories and romances that make up the Mass Effect universe. And we’re here to help.

As I’ve previously done for Dragon Age and The Witcher, I’ve assembled a beginner’s guide to the world of Mass Effect. A few notes: This post won’t spoil contain Mass Effect: Andromeda, but it will fully spoil the events of the first three games in the series. I should give a shout-out to the dedicated folks who have built the Mass Effect fan wiki, an immense tome of knowledge that was immensely helpful in fact-checking this article.

Lastly, while I am a pretty big Mass Effect nerd, I’m sure I’ve made a few mistakes. If you see any errors or oversights in this post I hope you’ll let me know.

This post has been retimed since its original publication.

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Image: Mass Effect


Mass Effect is set in the Milky Way galaxy in the late 22nd century. It’s the year 2183, shortly after humans have made first contact with alien races. Fifty years prior to the start of the first game, humans discovered alien wreckage on Mars that led to the development of new, advanced technology that allowed us to swiftly make contact with a variety of non-human races that had been coexisting throughout the Milky Way without our knowledge.

The tech that made all that possible is called Mass Effect technology, hence the name of the series. I won’t get too technical largely because this stuff is made-up and I don’t fully understand it, but the short version is that mass effect tech revolves around the use of mass effect fields, which harness the power of a new element called element zero in order to manipulate space-time.

Mass effect fields can be used alternately to power huge starships or to power gates that allow for easy faster-than-light (FTL) travel. Once humans learned to harness the power of mass effect fields, they discovered a network of gates called mass relays leading throughout the galaxy, each of which allowed for near-instantaneous travel to the far reaches of the Milky Way.

A Beginner’s Guide To The World Of Mass EffectA Mass Relay.

A Mass Relay.

All these wondrous mass effect devices didn’t just spring fully formed into the galaxy, nor were they the work of any of the aliens humans found on the other side of their first FTL trip. The mass relays, and mass effect technology in general, were believed to have been created by a lost, mysterious precursor race known as the Protheans. (The full story of their creation turned out to be more complicated.) The ruins humanity found on Mars were Prothean ruins. Little was known about them at the start of the first Mass Effect, and the original trilogy largely revolved around uncovering their story.

With mass effect drives and mass relays under our collective belt, humanity set forth to sort of dickishly elbow its way into the galactic spotlight. We did so driven not just by our ambition and impressive technology, but also with help from humans imbued with biotic powers. A certain small percentage of humans, known as as biotics, began exhibiting powers after being exposed to element zero. Those powers manifest as glowing blue energy — they’re able to generate their own self-contained mass effect fields. Biotics are able to throw around and detonate self-contained energy fields, and can be fearsome warriors.

Humanity quickly made a name for itself as an aggressive, ambitious race. We even started a brief war called the First Contact War with the first aliens we met — in fairness, they kinda started it — and despite our relative technological youth managed to hold our own.

A Beginner’s Guide To The World Of Mass EffectThe Normandy and the Citadel

The Normandy and the Citadel

Humanity soon made peace with the other alien races of the Milky Way and were allowed access to The Citadel, a massive and oddly little-understood Prothean space station that served as the center of galactic trade and government for the Milky Way. The citadel was ruled by council members who represented the three council races — Asari, Salarian, and Turian, detailed below — who reluctantly allowed humans onboard the station. While our time on the galactic stage had been relatively short, most of the aliens we’d encountered had learned not to underestimate us and, usually, not to really like us.

The original Mass Effect trilogy centered on a player-created human protagonist named Commander Shepard, who could be a woman or a man. Shepard led the human race and, eventually, the rest of the allied races of the Milky Way galaxy in a lengthy and escalating war against The Reapers, a race of powerful killing machines from beyond our galaxy. Andromeda picks up near the end of the events of Mass Effect 2, so the preceding backstory remains the same for both games.

Before we get into the events of the main trilogy, let’s talk about aliens.


The non-human races of the Mass Effect universe run the gamut from thoughtful scientists to warlike barbarians, and if you play your cards right, you could usually have sex with at least one of them per game. Because Andromeda hits the ground running, it’s important to go into the new game knowing the differences among the major species. The writers assume that your character (and by extension, you) know a krogan from a turian, so you probably should. Let’s get to it.

A Beginner’s Guide To The World Of Mass EffectLiara T’Soni, thoughtful as always.

Liara T’Soni, thoughtful as always.

Asari are a blue-skinned race of aliens who all look like — surprise! — beautiful women. If you’ve seen someone on TV talking about Mass Effect and alien sex, chances are pretty good the scene you watched featured an Asari. Asari can live to be a thousand years old and as a result take a detached, long-term view of the galaxy around them. They’re able to reproduce with members of any sex or race, and each Asari is encouraged to look outside their fellow Asari in order to enhance and diversify their gene pool. They’re also all born biotics, though not all Asari use biotic powers.

Asari are one of the most respected and powerful races in the Milky Way, and they tend to hold positions of power and influence. Their native planet of Thessia features only briefly in the Mass Effect trilogy, which is too bad, since it would have been a cool place to visit. The most important Asari in the original trilogy is Liara T’Soni, a researcher who joined your crew in the first game and made frequent appearances throughout the sequels.

A Beginner’s Guide To The World Of Mass EffectMordin Solus performs his favourite song.

Mordin Solus performs his favourite song.

Salarians are another important race, best known as scientists and researchers. They have reptilian skin and a notably short lifespan, with the average salarian topping out at 30 or 40 years at most. They’re brilliant scientists and are responsible for much of the technological advancement shared by alien races across the galaxy. Hailing from the planet of Sur’Kesh, they’re notoriously pragmatic and unsentimental, and frequently willing to make sacrifices in order to benefit the majority.

Salarian scientists have been responsible for some incredible breakthroughs. They have also brought about horrible calamity. The show-tune loving scientist Mordin Solus is easily the most well-known salarian in the original trilogy, and one of the most beloved characters in any BioWare canon.

A Beginner’s Guide To The World Of Mass EffectGarrus Vakarian, after he grew his Riker beard in Mass Effect 2.

Garrus Vakarian, after he grew his Riker beard in Mass Effect 2.

Turians are a race of creepy-looking hardasses who usually act as law enforcement and muscle for the Asari and Salarians. Turians look sort of like talking catfish, with a beetle-like shell and a cat-like way of speaking and acting. They’re notoriously forthright, a warrior race that lives according to a military code. They helped design the starships used by the other council races, and are best thought of as the cops of the Mass Effect universe.

Turians were the first race humans made contact with after we discovered mass effect travel, and we fought against them in the brief but vicious First Contact War before everyone involved decided the turians probably shouldn’t have started out by shooting. The two most important turians in the original trilogy are Saren Arterius and Garrus Vakarian; the former, the antagonist of the first game, the latter a beloved crew member, ally and potential love interest for the run of the trilogy.

A Beginner’s Guide To The World Of Mass EffectWrex, who is really a big ol’ softie once you get to know him. Well, no he isn’t.

Wrex, who is really a big ol’ softie once you get to know him. Well, no he isn’t.

The krogan are a violent group of reptilian hardcases who look like what would happen if you crossed a horny toad with a stegosaurus. The krogan spent many years isolated on their brutal home planet of Tuchanka, where they evolved into the dominant species. They made their galactic debut thanks to the salarians, who enlisted their help to win a war against a deadly race of insect-like aliens known as the Rachni.

The krogan helped fight the rachni to near extinction, and in the process began to rapidly expand and conquer swaths of the known galaxy. That led to a war known as the Krogan Rebellion, which pitted the krogan against the other most powerful races in the Milky Way. The krogan rebellion was cut short when the turians deployed a devastating salarian-developed bio-weapon known as the genophage, which destroyed the krogan on a genetic level by causing almost all new krogan babies to be stillborn.

Since the genophage the krogan have fallen into decline and their numbers have dwindled. Various attempts to cure the genophage have all failed, though many krogan hold out hope that their species will still somehow survive. They are pretty hard to kill, after all. Notable krogan in the original trilogy include the mercenary Wrex in the first game and the genetically engineered super-krogan Grunt in parts two and three. (The krogan keep their names nice and simple.)

A Beginner’s Guide To The World Of Mass EffectTali, who my Shepard dearly loved and tragically lost.

Tali, who my Shepard dearly loved and tragically lost.

Quarians are a nomadic, tribal people who travel the galaxy in a huge migrant fleet called… the Migrant Fleet. They’re easily identified by the protective suits they wear, since their bodies aren’t able to filter all the germs they may encounter in their galactic travels. They’re notable tinkerers, constantly experimenting with new technology and creations, and are most infamous for creating the geth, a race of sentient artificial intelligence that eventually rebelled against them and conquered the quarian home planet of Rannoch.

The sentient android geth are one of the primary antagonist races in the main Mass Effect trilogy, and the quarians are often seen as pariahs by the other races for their role in the geth’s creation. Because of the geth, most true artificial intelligence in the Milky Way has been deemed illegal, and most organic races hold a deep-seated distrust of computer intelligence. The most well-known quarian is a woman named Tali’Zorah nar Rayya (or just “Tali” for short) who joined Commander Shepard on his or her adventures throughout all three original Mass Effect games.

A Beginner’s Guide To The World Of Mass EffectHanar are the best.

Hanar are the best.

Those are the big races, but just for context, a few other races include:

  • The hanar, a race of philosophical walking jellyfish that worship the protheans with religious fervor. (A long-running joke in the original trilogy featured ads for a TV show about a hanar special agent named Blasto.)
  • The Elcor, a funny group of Eeyore-like aliens who preface everything they say with the attendant emotion due to their lack of vocal inflection.
  • The Volus, a race of smaller (dare I say roly-poly?) aliens who tend to favour their mercantile strengths over their martial prowess.

I’ve discussed the various antagonist races already, but just to recap:

  • The Geth were a race of sentient artificial intelligence who rose up after being created by the quarians.
  • The Protheans are a mysterious, advanced precursor race that vanished mysteriously but are believed to have left behind all manner of useful technology including the mass relays.
  • The Rachni were intelligent, bug-like creatures who threatened to overrun the galaxy and were eventually put down by the council races with an assist from the krogan.
  • The Reapers were the big bad of the original trilogy, a race of unknowably powerful sentient machines who visited our galaxy on a set schedule in order to exterminate all life.

Speaking of that whole “Reapers exterminating all life” thing, let’s talk about what happened in the first three games.


While the characters in Andromeda set out on their journey before the most consequential events of the main trilogy took place, they then travelled for 600 years. Not only has the trilogy concluded by the start of the new game, characters in Andromeda also occasionally reference things that will mean a lot more if you know what happened in the first three games. I will now summarize what happened in each game as expeditiously as possible.

Mass Effect 1: Saren and the first Reaper attack

The first Mass Effect concerned a rogue Turian named Saren and his plot to pave the road for the Reapers to arrive and wipe out life in the galaxy. Saren was a well-respected Specter, an elite operative who represented the Citadel council and operated above the law. At the start of the first game, Commander Shepard is working as a special operations soldier who heads to a human colony to investigate reports of a recently exhumed Prothean artifact. (I played as a lady commander Shepard, so for the rest of this article I’m just gonna call Shepard a her.)

The colony is under attack by the robotic geth. In the chaos Shepard makes her way to the Prothean artifact and also learns about Saren, who has gone rogue and is leading the geth. She comes in contact with the artifact itself, which shows her a disturbing vision of galactic destruction. Shepard returns to the citadel and eventually manages to convince the council of Saren’s treachery. In the process she gets herself elevated to specter status, the first human to achieve the honour.

A Beginner’s Guide To The World Of Mass EffectThe council debates making Shepard the first human specter.

The council debates making Shepard the first human specter.

Shepard the specter is tasked with finding out what Saren is up to and stopping him. She’s given a badass starship known as The Normandy and told, more or less, to do whatever it takes.

In the process of her adventure she recruits a typically BioWare-y motley crew of helpers. Among them: Wrex, a violent Krogan with a complicated past; Tali, a wandering Quarian who may know more about the geth than she lets on; Garrus, an eager young turian who had been serving as a cop on the Citadel; Kaiden and Ashley, two human soldiers conscripted to join Shepard’s cause; Joker, a sarcastic ace pilot with bones so thin they break at the slightest touch; and Liara, an asari who has been researching the protheans.

Shepard tracks Saren across the galaxy and eventually uncovers the truth behind the rogue specter’s actions. Saren’s mind has been corrupted by a Reaper called Sovereign, a massive nautiloid machine intelligence that declares itself the vanguard of a looming, unstoppable invasion. Sovereign has the power to warp and mind-control biological life forms — this process is known as indoctrination — and is using them to set up the next in a long series of purges where the Reapers arrive and exterminate all life from the galaxy.

Shepard eventually learns that the Citadel itself is not just a space station but also a dormant mass effect relay, and if activated it will open a gate for the Reapers to begin the invasion of our galaxy. Sovereign tells Shepard that the mass relays were not the work of the Protheans at all, but rather were put in place to guide civilizations toward the Citadel and their eventual destruction.

A Beginner’s Guide To The World Of Mass EffectSovereign leads an attack on the Citadel at the end of the first game.

Sovereign leads an attack on the Citadel at the end of the first game.

With help from her entire crew as well as the Citadel council and fleet, Shepard catches up with Saren, who has landed an attack party aboard the Citadel. She stops him from opening the gate to the Reapers and, depending on how the player chooses to role-play it, can either help him take back control of his mind or simply kill him.

While Shepard is dealing with Saren aboard the Citadel, the rest of the fleet is fighting off Sovereign, who has arrived intent on destroying the council and opening the gate. Some fancy flying and a few moral choices later, Sovereign is destroyed, the Citadel is safe, and Shepard and most of her crew have lived to fight another day. The Reaper threat, however, remains.

Mass Effect 2: The Collectors and the Illusive Man

Mass Effect 2 started out with what is widely regarded as one of the most memorable video game intro sequences of all time. Shepard is leading her crew on a routine mission when the Normandy is attacked by a mysterious ship capable of bypassing her defences. The ship is destroyed and Shepard dies while attempting to get her crew out safely.

Shepard’s remains are collected by a shadowy group known as Cerberus, who use unknown technology to rebuild her from the cells up and bring her back to life. The resurrected Shepard then meets the leader of Cerberus, a mysterious guy called The Illusive Man, memorably played by Martin Sheen. The Illusive Man and Cerberus believe that humans are superior to all other races, and, he says, have brought Shepard back to investigate attacks that have been carried out on remote human colonies.

A Beginner’s Guide To The World Of Mass EffectThe Illusive Man, always one for a dramatic backdrop.

The Illusive Man, always one for a dramatic backdrop.

Shepard puts together another motley crew, bringing back Joker as pilot, Garrus as soldier and the quarian Tali, along with a genetically engineered krogan named Grunt, a mysterious assassin named Thane, an unauthorised artificial intelligence named EDI, and a few more characters we don’t have time to get into. They quickly learn of a new threat to the galaxy, chitinous aliens known as The Collectors who are attacking human colonies and abducting people for an unknown purpose.

Over the course of the game, Shepard and her crew learn that The Collectors are in fact husked out Protheans, the precursor race who they believed had built all of the technology that has allowed the modern-day races to communicate and travel as they do. Thousands of years ago the Protheans were a benign race that acted as architects for much of the galaxy as we’ve come to know it — they learned of and studied the races that would go on to become the council races, paving the way for those civilizations to eventually grow and prosper.

A Beginner’s Guide To The World Of Mass EffectThe Collectors

The Collectors

That all changed when the protheans came up against the Reapers, a seemingly unstoppable machine enemy bent on destroying all advanced civilizations in the galaxy. The protheans fought a desperate war against the reapers for generations until they were all but wiped out. A small subset of protheans survived, controlled and warped by the reapers until they became the evil husks Shepard and her crew were now calling The Collectors.

In the end, it turned out the Collectors had been kidnapping humans and melting them down in order to build a new Reaper that looked like a giant T-800 from Terminator. (Yeah, bit of an unsatisfying conclusion after a game’s worth of build-up.) In a last-ditch suicide mission, Shepard and her crew stormed the Collectors’ base of operations, destroyed the reaper before it could be activated and, if the player played his or her cards right, made it out with most of Shepard’s crew alive. The day was saved but, as at the end of the first game, the final showdown with the Reapers was only delayed.

Mass Effect 3: The final war with the Reapers.

Mass Effect 3 concluded Commander Shepard’s story by finally giving us the showdown with the reapers they’d spent two games building toward. The reapers were here, their plan to invade and exterminate had begun, and it was up to Shepard to lead an increasingly hopeless war against them. For Andromeda players, keep in mind that the following all happened while our new heroes were fast asleep in hypersleep.

Shepard is put in command of the combined war effort on behalf of all sentient life in the galaxy, tasked with unifying everyone in a desperate attempt to stop a seemingly unstoppable adversary. One last time Shepard assembled a motley crew aboard a cool ship, though everything had a much more fatalistic air this time around. It was the end, and everyone knew it. People were gonna die. Maybe everyone was gonna die.

A Beginner’s Guide To The World Of Mass EffectA Reaper blows up a ship carrying a little kid at the start of Mass Effect 3, as if we needed even more reason to want to stop them.

A Reaper blows up a ship carrying a little kid at the start of Mass Effect 3, as if we needed even more reason to want to stop them.

Because it was the last game in the trilogy, a whole lot of shit went down in Mass Effect 3, some of which would play out very differently depending on the choices you made in the game. The loyal quarian Tali could watch her entire home fleet be destroyed, then commit suicide right in front of you. Or not! That didn’t have to happen! Shepard could ally herself with the geth in order to fight off the reapers, or not! Maybe not. All of Shepard’s teammates could die before the end, or not! Maybe they didn’t die!

Whatever choices you may have made throughout the game, it all boiled down to a showdown between Shepard, her army, and the Reaper fleet. Shepard spends most of the game working on a weapon known as The Crucible, which is seen by many as the one weapon that could conceivably do real damage to the Reaper fleet. Shepard hurriedly flies from planet to planet, avoiding the mass carnage being wreaked by the Reapers while hunting for Prothean artifacts that can help with the completion of the weapon, in particular chasing something known as “The Catalyst,” a crucial component to the finished weapon.

A Beginner’s Guide To The World Of Mass EffectPictured: Shit going down in space above the Earth. It was a real fracas.

Pictured: Shit going down in space above the Earth. It was a real fracas.

Meanwhile The Reapers have been systematically wiping out pretty much everyone — the asari homeworld lays in ruins, the turians are screwed, even the krogan aren’t doing so well. As her frantic mission proceeds, Shepard learns that the Catalyst is in fact The Citadel itself, and that the space station has the capacity to activate a massive weapon that could wipe out the reapers for good. She charts a course for Earth, towing the Citadel alongside, arriving just as the Reapers are finishing up melting the planet’s population. The Illusive Man turns up one last time to fuck everyone over and tip the Reapers off about the Catalyst, which causes the good guys to lose control of the Citadel just as it arrives in our solar system. (Some of the specifics are a little hazy here for me, but I’m pretty sure I’ve got all this right.)

Shepard leads her crew in an all-out ground assault against the Reapers in London, during which many of her crew sacrifice themselves to get her to a tractor beam that will transport her up to the Citadel. Once on board, the thinking goes, she can activate the Crucible weapon and take the Reapers down. One thing leads to another, the fight doesn’t go well, lots of people die, and Shepard winds up alone on the Citadel looking down on the ruins of humanity as the Reapers decimate all life on earth.

A Beginner’s Guide To The World Of Mass EffectThe wreckage of the Citadel/Catalyst in the aftermath.

The wreckage of the Citadel/Catalyst in the aftermath.

Then a bunch of stuff happens that I’m not really going to detail here, both because it’s all kinds of esoteric and complicated and also because it culminated in an ending so controversial that it led to a massive fan revolt, countless aggrieved blog posts and YouTube videos and, ultimately, a patch from the developers that fleshed things out. There were strong arguments from many angles about the way BioWare’s writers chose to end their trilogy, and I don’t really want to re-litigate the whole thing here.

Short version: First, the Reaper-indoctrinated Illusive Man shows up on board the Citadel and tries to convince Shepard that she can use the Crucible to take control of the Reapers. He’s cut short when she either shoots him or convinces him to shoot himself. Then, a mysterious AI construct appears to Shepard in the form of a little kid (don’t ask) and explains that this is all part of a preordained cycle. All of it: The protheans, the rise of the council races, even the Reapers. Whenever galactic species evolve past a certain point, the Reapers come back and wipe them all out. For countless millennia, organic life and machine life have never been able to truly coexist.

In the end, Shepard is given control of The Crucible and with it, the ultimate choice as to how to proceed. She can take control of the Reapers, synthesise organic life with artificial life, or destroy the Reapers and all other machine life in the galaxy. No matter which option she took, life as we knew it ceased to exist. Some of your crew (or even Shepard herself) may or may not have survived, and a lot of what happened was contingent on how many sidequests you performed to get your “war readiness” score up during the main game.

Long story short: Everything went to shit, pretty much everyone died, and it’s not entirely clear what happened after that. The end.

Whew! Kind of a downer ending there, but remember, it’s also a beginning. The whole time all that was happening, the cast of Mass Effect Andromeda were tucked safely in their little cryo-beds, dreaming of a new galaxy and blissfully unaware of all the rockin romance and robot violence taking place in the home they left behind.

There are of course dozens more Mass Effect side stories, supporting characters, minor conflicts and weird robots that I’ve left out, but I’d say we’ve covered the most important stuff. If there’s anything you think bears a mention, by all means mention it in the comments.


  • The krogan are a violent group of reptilian hardcases who look like what would happen if you crossed a horny toad with a stegosaurus

    Not stegosaurus. You probably mean triceratops, although no horns puts Krogan somewhat closer to protoceratops, which didn’t really have defined horns.

    You also forgot to mention that Volus are capable of supreme feats of biotic prowess. Indeed, they can sometimes become biotic gods…

  • Tell me again exactly what the goal of Sovereign/Saren was in the first game?

    If the Reapers simply left Saren alone, wouldn’t have there been no need to inform the races they were all going to die?

    They could have just turned up to the Citadel (after doing what they did in 3 and obliterating each home world) and it’d be job done, beer time.

    • He was indoctrinated by Sovereign, though he didn’t really realise that till the end.

      He was aware that the reapers were coming… though he didn’t know they wiped everyone out.
      He believed that by submitting to them the species of the galaxy could be saved from elimination… as opposed to being wiped out completely for displaying resistance.

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