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These are recommendations made by Tropers for Mass Effect Crossover fics, all of which have to be signed to stay on the page. Feel free to add a fanfic of your own to the list, but remember to use the template found here.

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     Anime & Manga 
Alpha and Omega by Xed Alpha
  • Recommended by VictorioMWolff-Haddock
  • Crossover with: Neon Genesis Evangelion
  • Status:
  • Synopsis:
    • Alpha and Omega: Long after the end came the next beginning. Something lost since time immemorial is about to return and two souls, so different and yet so alike, are set to clash.
    • Alpha and Omega Book 2: The Fallen: Having been cast down at the conclusion of his battle with the Leviathans, Shinji Ikari finds himself caught between his new world and an old one that looks suspiciously familiar. And while he may be trapped with only one companion, a certain someone universes away prepares to go to any lengths to see his return.

Bad Things Come in Twos by bullethead
  • Recommended by: Char Aznable
  • Crossover with: Mobile Suit Gundam: Iron-Blooded Orphans
  • Status: Ongoing
  • Synopsis: 50,000 years ago, the Protheans & Reapers annihilated each other. Now, in 323 Post Disaster, a group of alien explorers cross paths with Tekkadan at Saisei. Now Tekkadan and Teiwaz are playing a high stakes game, with the fate of humanity in the balance. AU for Mass Effect, AU for IBO after Episode 9.
  • Now has a TV Tropes Page: Bad Things Come In Twos
  • Comments: I stumbled on this gem and thought I'd share it with everyone. I especially like the initial intrigue with the alien crew and Teiwaz/Turbines/Tekkadan, as well as the interactions between the humans and aliens.

The Illusive-Emperor by Nicolai Alvin Hubert
  • Recommended by: romancechina88
  • Crossover with: Code Geass
  • Status: Dormant
  • Synopsis: The first crossover between Mass Effect and Code Geass by three writers who have joined together to write this fic. Where in this universe Humanity has problems with the Turians and the batarians as well. But in the Shadows lies a figure known only as the Illusive man, who is making his move to protect humanity's place in the galaxy.
  • Tags: Rated M, Adventure/Sci-Fi

Mass Effect 2: Naruto's Mission by I.K.A. Valian
  • Recommended by: autopanda
  • Crossover with: Naruto
  • Status: Dead
  • Synopsis: Naruto wakes ten years in the future with no memory of what happened to get him there. Following the only clue he can find, he embarks on a mission to find and bring home Sasuke and Sakura who are lost in a galaxy threatened by Reapers.
  • Comments: At first, it may SEEM like a sequel fic, but the author does not have any other Mass effect/Naruto fics. It's actually pretty good, if a little bit shocking due to the fact that Naruto was indoctrinated and apparently turned into an asshole.

Misplaced by Deus Swiftblade.
  • Recommended by: Vercalos
  • Crossover with: Naruto
  • Status: Complete
  • Synopsis: When the seal broke and he opened his eyes, he had hoped to see his friends standing around him, welcoming him back to life. But now he's in a different time and all of his friends have long since passed away. Now the only thing he can do is put what he has been trained to be to good use and serve the galaxy from the shadows.
  • Comments: A rather expansive AU fic that doesn't just stick Naruto into the Mass Effect universe as part of the Normandy crew, but actually rewrites the entire universe to fit into the Naruto universe, with every character having traits and abilities that would logically fit into the Naruto universe, like James Vega having a summoning contract, and Kasumi Goto being descended from the Yamanaka and Nara clans. Also, at over a million words, it is a freaking doorstopper.

Naruto Style Mass Effect by TheBaneOfOlympus91
  • Recommended by VictorioMWolff-Haddock
  • Crossover with: Naruto
  • Status:
  • Synopsis: Commander Shepard couldn't be revived through Project Lazarus, but the Illusive Man always has plan. If he can't have Shepard, he'll just have to have the next best thing; a blond haired ninja from the Leaf Village.

Protoculture Effect by Cyclone
  • Recommended by: SAMAS, GrantMK2
  • Crossover with: Robotech
  • Status: Dead
  • Synopsis: Another in the "Systems Alliance is replaced by Sci-Fi series X" class of fanfics, this time it's Robotech. The Sentinel Alliance is an entire rival bloc to the Citadel, with tensions running high after the aborted wars against the Turians and Batarians. Join controversial Human Spectre John Shepard and Lt. Commander Jane Hunter as they hunt down the rogue Spectre Saren.
    • It does a fairly good job of properly melding two very different franchises, gives different characters time to shine and manages to avoid letting mechs solve everything.
  • Author's Comment: Nice to see my story here, but don't forget to check out the Codex, which includes some entries not found attached to the main story.

Shepard's Bizarre Adventure by TheOneMoiderah
  • Recommended by: ZoneAdv944
  • Crossover with: JoJo's Bizarre Adventure
  • Status: Dead; last updated June 2016
  • Comments: The story is an adaptation of Mass Effect 2 and follows the adventures of Josephine Shepard. The story goes Off the Rails very quickly with Shepard getting a Stand, Kars being picked up and taking over the Collectors, and Liara being turned into a vampire! Overall, the story is a perfect blend of Mass Effect and the fabulous insanity that is JoJo.

Through dust and Ashes by Virdu
  • Recommended by: Airemir
  • Crossover with: Naruto
  • Status: Dead
  • Pairings: Naruto/Hinata, Hidan/Kurotsuchi
  • Synopsis: The world of the Shinobi is at an end, will the arrival of the first Human Spectre grant them salvation, or is it just the beginning of a new war?
    Comic Books 

Garfield Effect: Galaxy Adventure by ShakepeareHemmingway

  • Recommended by: Psythe, Xyseni
  • Crossover with: Garfield
  • Status: Dormant
  • Synopsis: Garfield leads Shepherd and crew to save the galaxy! Shepherd turns out to be quite the ladies man! A third exciting thing probably also happens!
  • Comments
    • Psythe: Never in my wildest dreams did I imagine that I would see a Garfield/Mass Effect crossover, and never in those same dreams did I believe I would ever laugh so hard. This is very much in the tradition of Full Life Consequences, truly great badfic, and I cannot recommend it highly enough. If you've ever wanted to see Shepard get it on with every girl in the game as well as a Hanar, a Varren, and all of the Krogan females of Tuchanka at the same time, this is the fic for you. Every time I read it something new and amazing comes out of it. THESE ARE MY OLIVE BRANCHES.

Shadows and Dust by HistoricalHijinks
  • Recommended by VictorioMWolff-Haddock
  • Crossover with: X-Men
  • Status: Ongoing
  • Synopsis: Shattered, Reborn, Reforged, Remade. The gaze of the Pheonix Force, seeking purpose and understanding, falls upon the Reapers and their harvests. Disgusted by their perverted, farcical 'cycle', it decides to wipe their stain from the multiverse. Needing a perfect host, it waits tens of millennia until, as Hannah Shepard is miscarrying due to eezo radiation, it finds one in her womb.
  • Comment: Two badass female Shephard in one story. We got the Badass Normal mother and the vessel of Phonex Force daughter.
  • Has a Trope page.

We'll believe a man can WHAT?!, Thuktun Flishithy
  • Recommended by: Tron 80, Unclouded TJ
  • Crossover with: Superman
  • Status: Ongoing
  • Synopsis: The year is 1964. Mass Effect universe meets Silver Age Superman. Hilarity ensues.
  • Tags: Comedy, Action.
    Franchise 

The Art of War by Mithrao -- Fanatic of Thrawn

  • Recommended by: Tallens
  • Crossover with: Star Wars Legends
  • Status: Dead
  • Synopsis: Something is out there; Something is coming. It threatens my people, and I will do anything to defend them. Yet, they did not accept my methods and I was exiled. It matters not, I do not need their permission to fight for them. I will return, and this new galaxy will aid me in my plans. I will teach them of our foe, and they will learn to face it. They will learn: I. Am. Thrawn.
  • Comments: Looks to be shaping up to be a retelling of Mass Effect, with Grand Admiral Thrawn as a character. Despite that, if the first chapter is any indication, it should be interesting to watch unfold. Regardless of how the rest of the story winds up, that first chapter is worth a read for any fan of the Grand Admiral.

Mobile Suit - Mass Effect: The First Contact War by Mister Smallville (Ao3 Link)
  • Crossover with: Gundam
  • Status: Ongoing
  • Synopsis: Two worlds collide, neither prepared for the other. The Solar Sphere Congress -successor to the long gone Earth Federation- unwittingly starts a galactic crisis when it makes first contact with a very angry, very trigger happy Turian Hierarchy.
  • Comments: This sets on far future of Universal Century. And after first contact, Turians ended up creating their own Gundams.

Never Fade Away by Ideas-Guy
  • Recommended by VictorioMWolff-Haddock
  • Crossover with: Cyberpunk
  • Status: Ongoing
  • Synopsis: Lives are cheap and money is everything. That's how the orphanage made its money - lending out children for human expirementation. L is an old man at the age of fifteen and he knows he doesn't have much time left. All that mattered was getting out, but he soon learns that the world is a lot bigger than Night City. And that the galaxy is a lot bigger than Earth.

Terran Federation by L4 of the WEST
  • Recommended by: gregornguyen
  • Crossover with: Starship Troopers
  • Status:
  • Description:
    • Terran Federation - The Terran Federation is nearing the end of the long Second Bug War, thanks to the discovery of hidden ancient structures known as Mass Relays and with Klendathu has been annihilated by a Nova bomb, and peace is on the horizon, however, others have plans for conquest, and the use of the Mass Relays will not go without consequences, for both themselves and the Galaxy at large.
    • Terran Federation: Counterstrike - It's been 8 years since the end of the 2nd Bug war. Humanity is starting to enter its golden age in the galactic stage, with technology no one can replicate, with allies that no one has accepted, and a military capable of taking on any competitor it seems. But that will change, those who employ chains are circling like wolves, and an enemy thought dead return
  • Comments: Set before ME 1 and after Starship Troopers: Invasion, the story is a retell crossover fic with Terran Federation in place of System Alliance making first contact with the Turians. Its a fusion of different Starship Troopers incarnations, with a heavy dose of AU.A complete deconstruction of First Contact War with the Terrans becoming close ally of the Turians against the odds of the universe
    • An interesting fic to read, consider the meritocratic values in the Hierarchy is almost the same as in the Federation, The story has a lot of problems with grammar and spelling, but the idea was quite interesting.
    Literature 

Burn, Shepard, Burn by Otempora

  • Recommended by: Theriocephalus
  • Crossover with: The Witcher
  • Pairings: Fem!Shepard/Garrus
  • Status: Ongoing; all individual stories are completed one-shots.
  • Synopsis: Setting transplant — characters and location names from Mass Effect, setting otherwise based on The Witcher. The stories follow Shepard of Mindoir, a cynical sixty-and-change-year-old Witcher, and Garrus, an idealistic nobleman's son, as their respective travels take them in and out of assorted misadventures and they cross each other's ways on multiple occasions. Shepard's background is a low fantasy equivalent of Colonist/Ruthless.
  • Comments: Excellent writing, good humor, skillful insertion of the Mass Effect cast into The Witcher's world, and generally a fun read.

Emergence by Brasc
  • Recommended by: blerg223
  • Crossover with: The Draka
  • Status: Dead since 2012
  • Synopsis: The Draka crossover. When a survey team for the Domination of the Draka discovers alien ruins on Mars, Earth — and the galaxy at large — will never be the same.
  • Comments: A seamless integration of divergent species of humanity featured in The Draka series with the Mass Effect universe. Beginning shortly before the end of The Stone Dogs and continuing to and beyond the First Contact War, this extremely well-written fic demonstrates a superb understanding to the lores of both series and depicts the consequences of the discovery of mass effect technology on the Protracted Struggle, as well as interesting and believable military and diplomatic interactions between the hypercompetent ultramilitaristic transhuman Domination, the fledgling Systems Alliance-esque United States of Samothrace, and the comparatively liberal and idealistic Citadel races. Though those unfamiliar with The Draka series may be a bit lost at first, this remains eminently worthy of a read.

Exiled by Fantasy Ra
  • Recommended by: Gentlemens Dame 883
  • Crossover with: Worm.
  • Status:
  • Synopsis: When it is all over, Taylor Anne Hebert tells her story. One in which a young man by the name of Sebastian Shepard features. A young man of strange powers, stranger mindset and the most fantastic tales of aliens and worlds among the stars.

Ghost Story by Nuts!/Norwest
  • Recommended by: Gentlemens Dame 883
  • Crossover with: The Dresden Files
  • Status: Dead
  • Synopsis: The Dresden Files crossover, spoilers for the end of Changes and start of the eponymous canonical book. Harry Dresden is dead, and so is John Shepard circa Bring Down the Sky. Orders on high come in to send them back to the land of the living... the other guy's land of the living.

Harry Potter: Geth by mjimeyg.
  • Recommended by: pkempf
  • Crossover with: Harry Potter
  • Status: Complete
  • Synopsis: During the final battle Harry is hit with a luck spell... but who exactly got lucky? Harry finds himself in the future fighting a new war when all he wants to do is have a nice and easy life. So he decides to have fun instead.
  • Comments: A really excellent humor and adventure fic wherein Harry is sent two-ish centuries into the future by Hermione's luck spell, only his (literal) re-entry doesn't work out all too well for him, so he finds himself almost totally rebuilt by the Geth, who promptly declare him their Emissary. He proceeds to rampage through the galaxy making it a better place in that way that only Harry can. Ships are Harry/Tali and M!Shep/Ashley, at least mainly. Well worth reading even for the dialogue alone.

The Lion by Jaenera Targaryen
  • Recommended by: larrynguyen
  • Crossover with: Legend of the Galactic Heroes
  • Status:
  • Synopsis:
    • The Lion Awakens - Thirteen years have passed since the death of Emperor Reinhard the Invincible. Humanity has begin to rebuild, but tensions are high in the realm of the Golden Lion. But as new enemies emerge, and a bigger galaxy is discovered, it seems that the old adage may yet be true: only a common enemy can bring Humanity together.
    • The Lion Unleashed - Thirteen years have passed since First Contact. The New Galactic Empire is the mightiest nation in space, its vast fleets and armies undefeated. But the shadows stir, seeking to cast all civilization into darkness. Against an evil older than life on Earth, will the Golden Lion rise or fall?
  • Comments: A very well written story with a much more realistic takes on the Mass Effect Galaxy, how the Empire deal with the Citadel, and showing how obsolete and limited the technology of Mass Effect was compared to the technology of the Empire. The Council in this fic is also much more rational-minded and was much wiser than the Alliance politicians from the OVA series. Another note, Desolas instead of become a Husk is now a First Contact War veteran who have respects for humans, while Saren motive for his human xenophobia is now much clearer as it was the shame from the defeat of the Hierarchy in the First Contact War. Garrus also make an appearance as a military advisor for the Fleet Admiral of the Turian Fleet, which reminded me of the moments when several Admirals in the OVA also tend to neglect their staff officer's advices and incompetent to the point of making grave mistakes which endanger their lives and reputations.

     Live-Action Films 

Matrix Effect by unity9

  • Recommended by: MetalKing1417
  • Crossover with: The Matrix
  • Status: Complete
  • Synopsis: Imagine what if the Human/Machine war ended with a truce and humans merged with the machines only to find a Mass Relay many years later. Read as humans explore this relay and find out where this rabbit hole will take them.

The Quarian-Princess Bride by theblueninja
  • Recommended by: Full-Paragon
  • Crossover with: The Princess Bride
  • Status: Complete
  • Synopsis: One day when the Catalyst is sick, The Illusive Man comes to read him a very special book.
  • Tags: Rated K, Humor/Parody
  • Comments: Has the cast of Mass Effect in the role of the characters in Princess Bride, with a few twists on the plot to fit the new characters.
    Live-Action TV 

Apostle's Message by Lone-ranger1

  • Recommended by: EGuardian101
  • Crossover with: Stargate SG-1
  • Status: Dormant; last updated January 2018
  • Synopsis: When the Reapers see the threat Shepard poses, they enact a backup plan millions of years old. A single Reaper will unleash his fury and two galaxies will never be the same. Stargate SG1/Mass Effect
  • Comments: The original wasn't anything special, but the redux fixes the majority of the issues and delivers. Does a good job mixing ME story with SG-1 Season 8, and characterizations are spot on and entertaining. Especially Garrus as a Badass Snarker. Takes place immediately after Horizon, and before New Order Part 1, and merges the two universes together. MShep as a Paragon who's turned Renegade. Has a healthy mix of drama, action/adventure, with a good dose of humor. Takes awhile to get into the main story, but well worth it.

The Babylon Effect by Andrew James Williams
  • Recommended by: kilroy11235
  • Crossover with: Babylon 5
  • Status: Dead
  • Synopsis: A pre-ME1 crossover with Babylon 5; The Terran Systems Alliance, a member of Citadel Space, encounter the Minbari and accidently kill their leader. The resulting war goes a little differently.
  • Comments: Mass Effect already had a Babylon 5 feel to it, and this blends them together quite well, giving a plausible reason why the races from both stories never originally encountered each other.

Drift by Peptuck
  • Recommended by: Zaptech, USA Bobcat
  • Crossover with: Terminator: The Sarah Connor Chronicles
  • Status: Dead
  • Synopsis: Terminator: The Sarah Connor Chronicles crossover taking place over the events of Mass Effect 2. Shepard receives an update to his team dossiers: a scientist specializing in artificial intelligence named Allison Young. When he goes to recruit her, however, he quickly discovers that she is far more than she lets on.
  • Comments: What makes this story effective is the characterization of Cameron/Allison; she's presented as two semi-separate entities in one body, and has a curious duality between the cold, logical machine that is Cameron and the much more human construct that is Allison. While the action sequences are solid, the real draw is Cameron/Allison's interactions with Shepard and the larger Mass Effect setting, and how she's had to adapt over the centuries to a galaxy that distrusts AI. There are some hints of Cameron/Shepard.

Through A Temple by DesertChocolate
  • Recommended by: Mikeal52
  • Crossover with: Star Trek: Deep Space Nine
  • Status: Dead; last updated August 2016
  • Synopsis: The Normandy and its crew are forced into the Trekverse by the Reapers. The Defiant is there to meet them. Now, two sets of very similar groups are forced together, fighting for whats right. In between just hanging out of course.
  • Comments: The story takes place after the Citadel DLC of Mass Effect, and during Season Five of Deep Space Nine. Basically an excuse to see two universes interact and fight alongside one another. One thing to mention is that the author also brings in the Multiplayers, developing them as their own characters alongside everyone else. All in all, a fun story if you like seeing Shepard and Sisko using Mass Effect Tech to kill Star Trek baddies.
    Tabletop Games 
The Crusade of the Lost by Ninoslav
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Warhammer 40,000
  • Status: Ongoing
  • Synopsis: A fleet of Imperial reinforcements, Mechanicus detachment, and a chapter of White Eagles meant for Cadian sector are swallowed in the unruly sea that is Warp. They emerge into a new universe, one without the Emperor, their faith strong, they will see this galaxy conquered.

Exodus of Stars by keiranhalcyon2010
  • Recommended by: MetalKing1417
  • Crossover with: BattleTech
  • Status: Dead
  • Synopsis: BattleTech crossover. Aleksandr Kerensky has led the war weary Star League Defense Force on a two year long journey into exile. A chance decision leads to a long awaited discovery, and final proof that humanity is not alone in the cosmos.
  • Comments: There are several interesting changes to the canon that make this interesting, even for a Fusion Fic/AU, one of the most notable being Humanity making a peaceful first contact with the Quarians, as opposed to the usual canon and violent first contact with the Turians. All together a good read.
  • Now has a page (under construction).

First Contact with the Angels by AntrosAscended
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Warhammer 40,000
  • Status: Ongoing
  • Synopsis: Horus rebelled against the machinations of Chaos and sacrificed himself for the Galaxy; Lorgar's Rebellion finally seems to have become a distant memory for the Imperium. On the 30th Anniversary of the Warmaster's death, a new swath of space would be found by accident, setting in motion whole new possibilities or new failures.

Glorious Shotgun Princess by Gregg Landsman
  • Recommended by: Fenix, Gamerex 27, Andyroid, Peteman
  • Crossover with: Exalted
  • Status: Complete
  • Synopsis: The Exaltation of the Unconquered Sun is a tricky thing. Especially when it doesn't come with an manual. Jane Shepard, who was able to talk Spectres into suicide before getting a spiritual superweapon grafted to her soul, has a new advantage. Crossover with Exalted.
  • Comments: It's written by the same author who wrote Nobody Dies. Notable moments include Shepard literally punching the Kepral's Syndrome out of Thane.

Hammerhand by Colonel Mustard
  • Recommended by: hodaza
  • Crossover with: Warhammer 40,000
  • Status: Complete
  • Synopsis: A crossover with Warhammer 40,000: While on their way to battle the Greenskins, Captain Malleus of the Sons of Thunder and his command squad are hit by a shock attack gun and blasted all the way back to the early 3rd millenium. Shepard is dead, human colonies are disapearing and its time for the Astartes to do what the Astartes were made to do. Long, well written and finished.
    • The sequel, Angels Of The Storm, is also finished.
    • TheArmada: Written with incredible skill and displaying mastery of action stories. Not only does it provide and epic, Epic, EPIC closure to the ME universe that some fans have missed in 3, but it does so in a way that feels like a natural evolution of both the canon characters and the universe itself. Angels of the Storm is slightly different from canon due to having been written before ME3 came out, but I can't complain, I found this better than canon. Best work of literature I have ever read, fan-made or published.

Last Heresy by Gaius Marius
  • Recommended by: Batman76, MetalKing1417
  • Crossover with: Warhammer 40,000
  • Status: Dead
  • Synopsis: The Galaxy burns in the fires of endless war.. The Citadel species arose in the vacuum left of the Age of Strife, conquering and colonizing worlds filled with the savage descendents of humanity. But now, humanity's nigh-immortal protector has returned as its Emperor. Against the might of the Citadel, His vast and terrible armies clash. At the head of Terra's armies are his 17 sons, the mighty and wondrous Primarchs and their legions of Astartes. In this galaxy, Night Haunter greets the Turians at first contact, Horus' legions push towards the Citadel, Magnus faces down the Asari on Illium, Leman Russ leads the Vylka Fenryka to destroy the Salarian homeworld and the Primarch Angron is sent to take the world of Eden Prime. Despite the machinations of the Citadel, the Emperor's great designs twist towards fruition, for the Reapers are coming and He has found a solution.

The Mission Stays the Same by Ursakar / Regina Dea (took over)
  • Recommended by: USA Bobcat, MetalKing1417
  • Crossover with: Warhammer 40,000
  • Status: Ongoing (taken over by another writer, last updated February 2020)
  • Synopsis: Just after Shepard comes back from Project Overlord, days after regaining life, EDI detects a signal from the nearby planet Aite. When Shepard investigates, she finds a very confused Imperial Guard Stormtrooper and an Eldar Farseer.
  • Comments: I found this a quite interesting crossover. Captain Gallardi (the Stormtrooper) incorporates Mass Effect technology in his gear, such as Mass Effect style armor, but also keeps his hotshot lasgun, which bypasses kinetic barriers. The technology issue gets taken care of quickly, but I found that everyone was in character, Gallardi having been part of an Inquisitor's retinue and thus slightly more easy with Xenos. He still refuses to allow Mordin to inspect his weapons or armor, though he eventually starts warming up, he has not yet lost his xenophobia entirely. Shepard is female, and follows most of the Fanon Fem Shep ways, but is very much a character, not an insert. Maeteris (the Farseer) has not joined the team on a ground mission yet, and focuses more on seeing the future, though in typical Eldar fashion, will hint and nudge Shepard, but never tell her outright.

Mythos Effect by Omniscent1
  • Recommended by: Drgyen
  • Crossover with: CthulhuTech
  • Status: Ongoing
  • Synopsis: Humanity has won the Aeon War and has since expanded and thrived. How will the galaxy fare with this new power?

Primal Beings, New Horizons by Trico216
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Warhammer Fantasy
  • Status: Ongoing
  • Synopsis: Lustria is destroyed, and the lizardmen depart for the stars. Finding an ancient gateway, what will the children of the Old Ones find on the other side?
  • Comments: The Lizardmen replace Humans in this story. Even John Shephard will be a Saurus.

Technophiles by thelordofdarkreunion
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Warhammer 40,000
  • Status:
  • Synopsis:
    • Technophiles: When the Cult Mechanicus learns of the existence of the A.I.'s known as the Geth and Reapers, they decide only one thing can be done, and enlist the help of Quarians to fight once more for their ancestral home.
    • Technophiles and Militarists: The Reaper invasion is nigh. Outnumbered and outgunned, the Citadel must turn to two new, dangerous allies for salvation: the Adeptus Mechanicus and Imperium of Man.
    • Things Alliance and Imperial Forces are No Longer Allowed to Do: As blending cultures and bored soldiers often goes, both the Alliance and Imperial militaries have gotten up to some very interesting hijinks. Admiral Hackett and the Commissariat have decided enough is enough, and posted these handy rules for their respective soldiers to follow.
  • Comments: A great blend of both franchises. While there certainly changes to the Alliance's lifestyle eventually, neither side is superior to the other.
    Video Games 

A Red Letter Day by open_sketchbook

  • Recommended by: GaryGibbon
  • Crossover with: the Paradox mod for Command & Conquer: Red Alert 3
  • Status: Complete
  • Synopsis: It is the year 2183, and Humanity is still divided. Since the wholesale slaughter of the Turian Expeditionary Fleet at Shanxi by the highly-advanced forces of the Soviet Union and the Allied Federation of Planets, humankind has been attempting to repair the damage caused by the war. In a show of cooperation and trust, Commissar-Commander Shepherd and Lieutenant Alenko are sent with their teams in a joint mission, along with Spectre Garrus Vakarian, to investigate claims of an attack on the human colony of Eden Prime. What they find there sets in motion a chain of events that could spell the doom of every sapient species in the galaxy.
  • Comments: A crossover with the writer's already insane mod for Red Alert 3, and heavily inspired by the writings of Peptuck, this is crack fiction that takes itself very seriously. Shepherd as a commie? Time-travelling jet troopers with laser guns? Transorbital Normandy-sized tanks? Roman cyberpunk Turian mercenaries with 80s mohawks? This is Mass Effect crossed over with Red Alert and then turned all the way up to eleven. If you fancy something incredibly silly that manages to take itself very seriously, read it.

Blood and Fire by Tavi
  • Recommended by: Gentlemens Dame 883
  • Crossover with: Halo
  • Status: Dead
  • Synopsis: The Citadel races have long been at war with the theocratic empire known as the Covenant. Decades ago they came to the rescue of the newcomer known as "humanity" when the Covenant took a hostile interest. Today, Covenant forces attack the human colony of Eden Prime... Halo/Mass Effect, takes the Fusion Fic path rather than a straight crossover.

Consuming Direct Control by Hyliian
  • Recommended by: MetalKing1417, USA Bobcat
  • Crossover with: [PROTOTYPE]
  • Status: Discontinued
  • Synopsis: With nothing left for him in the galaxy but empty space and idle time, Alex Mercer finds himself recruited in Commander Shepard's fight against the Collectors. Crossover with Prototype.
  • Comments: A rather humorous fic if I ever saw one. Mercer's hyjinks driving Shepard bonkers is too much for anyone to resist. The only real flaw, as admitted by the author is the slight bit of over focusing on Alex, though it is almost always bearable.

Cycles Upon Cycles by The Incredible Muffin
  • Recommended by: Tallens, WAEGirl
  • Crossover with: StarCraft
  • Status: Ongoing
  • Synopsis: AU from Legacy of the Void on the Starcraft side. Right after they defeat Amon, Tassadar warns the three Korpulu races of a new threat on the horizon. Putting aside their differences (mostly) they start to rebuild and prepare for this new threat, which takes an unexpected turn when a strange device is discovered in a remote system…
  • Comments:
    • This one has some different takes the usual Stations of the Canon, such as the first contact with the ME side being with the Quarians, rather than the Turians, who are then attacked by Batarian pirates. The war with the Turians, and Council at large, doesn't happen for some time after that. The humans from the ME 'verse are all adapted into SC-style units, Shepard being a Spectre (the Ghost variant), Ashley a marine, Vega a Marauder, Zaeed a Firebat and Grunt a Zerg. And the Normandy is a Battlecruiser variant with a cloaking device.
    • Overall, characters are well-written and interact believably with each other, though there are chapter which seem to be entirely made up of characters conversing. It may seem to be skewed heavily in favor of the SC side, but it does make clear that if they went into a prolonged war the Koprulu races would eventually be at a disadvantage due to fewer numbers and because the Turians would learn their tactics.
    • Updating on a fairly regular basis, with large and developed chapters each time, seeming to indicate the author has the story planned out pretty well, if not already written completely.
    • Very heavily favoured for the Starcraft side. Basically everything from the background of the story to inside the story itself is set up to make the Starcraft side as strong as possible, and overtake anything from the Mass Effect side. It is a good story if you like Starcraft, but warning for Mass Effect fans, Starcraft is basically shown as superior whenever it is possible for the author to do so. If you perfer Mass Effect, it might not be the story for you.

Dishonored Effect by Darridus
  • Recommended by: VictorioMWolff-Haddock
  • Crossover With: Dishonored
  • Status: Dead; last updated March 19th, 2014
  • Synopsis: Corvo Attano, the newly reinstated Royal Protector of the Empire, finds himself lost in an unfamiliar world when the Outsider decides to take interest in the world beyond the Isles, and further still.

Eagle's Fall by CharNobyl
  • Recommended by: Zaptech, USA Bobcat
  • Crossover with: Command & Conquer: Tiberian Series
  • Status: Complete
  • Synopsis: Established in the same setting as Renegade, this story covers the First Contact War between GDI and the Turian Hierarchy — specifically, the bloody ground war that resulted in the alternate timeline of that story.
  • Comments: A well-written, gritty, and realistic depiction of how a war between GDI and the Hierarchy would have played out. Indications of a Gambit Pileup are starting to show as both the asari and Brotherhood of Nod agents have begun to appear.
    • USA Bobcat: Now completed, this is a great read. Even if you don't believe me, believe Peptuck himself! Peptuck has declared that he considers this to be the canon (well, fanon) prequel to Renegade, and Char-Nobyl is working alongside Peptuck on Renegade, including incorporating elements from Eagle's Fall. Fans of this story, rejoice! Specialist Locke lives! And is confirmed to being appearing in Renegade!

Exitium by Fluoxetine (Fanfiction.net link)
  • Recommended by: p0nypanda
  • Crossover with: Doom (2016)
  • Status:
  • Synopsis: As humanity stands on the brink of total extinction, Samuel Hayden, Director of the Unified Argent Corporation, enacts a desperate last-ditch plan to ensure mankind's survival. In another time, and in other place, a turian patrol ship encounters a mass relay unlike any other. The peoples of Citadel space and the Terminus have no idea that beyond it lies one thing: Doom.

''Force Effect: A Knights of the Old Republic & Mass Effect Crossover
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Knights of the Old Republic
  • Status: Ongoing
  • Synopsis: Shepard and her crew thought that The Crucible would save them and destroy the Reapers. They were wrong. New rules. New enemies. New war.

Harbinger by Peptuck
  • Recommended by: Wild Goose
  • Crossover with: First Encounter Assault Recon
  • Status: Dead
  • Synopsis: A rampage by an insane psychic on an Alliance colony draws the attention of Commander Shepard, Citadel Spectre and former FEAR point man. Events are set in motion that may mean the death of a galaxy, or salvation from the Reapers. ME/FEAR fusion. M!Shepard/Ashley.
  • Comments: Shepherd is the Pointman.

The Human War by Generatedname.
  • Recommended by: Omeganian
  • Crossover with: XCOM2
  • Status: Dormant; last updated May 2018
  • Synopsis: For centuries, since driving their Ethereal overlords off Earth, humanity has been at war with them. Now, an attempt to flank their enemy's territory makes them stumble across this little alliance calling itself Citadel Council...
  • Comments: The author already tried once to write a fic called When Civilizations Meet. That one was a regular crossover between XCOM: Enemy Unknown and Mass Effect. This one reads more like the XCOM universe meeting Renegade Reinterpretations.

I'm Nobody by free man writer (co-written with Jebest4781.)
  • Recommended by: Lermis
  • Crossover with: Kingdom Hearts
  • Status: Ongoing.
  • Synopsis: He didn't have anything when he was born. Just a name and number. But over time, what he had grew. He, with his friends began to understand that there was more to their existence then just their name and number. They will prove that they were meant to be real. To exist. To become something more than just a Nobody.
  • Comments: One of the rare few times that Mass Effect gets crossed over with a fantasy setting, and it's glorious. It starts very much like a typical "X character ends up in another world" setup, with Roxas mysteriously finding himself in the Citadel. However, over the course of the events the Kingdom Hearts and Mass Effect universes start blending more and more, and the cast of characters gets increasingly diverse, slowly but surely diverging from canon. It starts with the Heartless appearing in the Citadel and goes from there. It also introduces several new Disney worlds — or references — that were not included in the original games, such as The Incredibles, Treasure Planet, Lilo & Stitch, and more.

The Infinty Effect by creamofwheat2311
  • Recommended by: TimothyMan
  • Crossover with: Halo
  • Status: Ongoing
  • Synopsis: After discovering a Precursor artifact, the UNSC Infinity and the Sangheili Shadow of Intent are transported to a universe unlike anything they have ever seen, and forced into a war against a foe they never could have imagined: the Reapers. Alliances are founded, friendships are formed, and decisions are made that will change this galaxy forever. Post Halo 4, Pre ME3. AU.
  • Comments: I'm very new here so I'm sorry if my inexperience shines blindingly through, so a slightly more in depth synopsis is the Infinity and Shadow of Intent are transported to Mass Effect's Sol System just before the Reapers arrive. Overall I would give this an enthusiastic recommendation. First contact was done well, the space and land battles are fun, and the characters seem well written for the most part. Some things that bother me a bit is that Halo tech is buffed even more but it is at least somewhat balanced by being seriously outnumbered, and people are alive that at the moment is kinda hand waived how they survived. While this story is my favorite, I hope someone can give it a more detailed critical analysis.

In the Shadow of Gods by Anne Whyne
  • Recommended by: FarmerKyle
  • Crossover with: Halo
  • Status:
    • Original - Discontinued & Deleted
    • Rework - Ongoing
  • Synopsis: "They stand apart from humans as heroes, saviors, and gods among men. But when we stand in the shadows of gods, we fail to see the cost to them. Sometimes the only one that can understand the weight of the universe is someone else who bears it." A Halo/Mass Effect crossover.
  • Comments: One of the better crossovers of its kind, and a great fanfic all around. Shepard here is Paragon, with dashes of Renegade to keep things interesting. Also doesn't speed up the trust issue between John and the rest of the team, especially after Cortana tries to hack EDI. Great characterizations all around, the fights are well done, and overall a great story!
    • Abandoned, as of now. The author has issues with some of the stuff that goes on over at ff.net. Her full explanation can be found here. It's a damn shame from where I'm standing.
    • Deleted from FF.net by Critics United.
      • First chapter of re-write now posted at relevant link here. Hallelujah.

The Last Spartan by Dino Jake
  • Recommended by: Gamerex 27, Crow T R0bot
  • Crossover with: Halo
  • Status: Dormant; last updated December 2018
  • Synopsis: An AU fic in which the Halo and ME universes share the same galaxy. After a well deserved rest in cryo-sleep, Master Chief finally awakens... to a whole new galaxy.
  • Comments: This may very well be the only well-written Halo and Mass Effect crossover this Troper has ever read. Everyone is in character, the alien races of Halo do a very nice job of changing up many different events in the game (all for the better), and the few OC'S in it (which are not introduced until chapter 10) are very realistic and engaging characters.
    • The story starts off garbage. The idea of the Halo races giving up their most powerful capability, their slipspace drives, because of a smaller power asking them to is ridiculous, as is their banning of A.I.s no matter how many ass-pulls the author tries. It's a very sloppy attempt at merging Halo and ME.

Man off the Moon by FiendLurcher.
  • Recommended by: Ylzbq, Tropers/allfictions, Dyuran.
  • Crossover with: Fate/EXTRA
  • Status: Dormant; last updated December 2020
  • Synopsis: Hiding from the force that ravaged it 14,000 years ago, the Moon Cell slides into another world where humanity advanced along a completely different axis. There a man of many regrets is given a second chance to walk among the living, but when granted the ability to walk away... Can he take it?
  • Comments: This fic is unique in that so far, any changes Emiya makes to the timeline are not because of using his magecraft, but rather because of his experience and growing friendship with Shepard (who here has just signed up for the military).
    • Dyuran: A highlight of this fic is how dedicated the author is to incorporating the Mass Effect lore (as found in the in-game codices), the Fate lore, real science as well as taking into consideration the real-world applications of those when logically extrapolated (which is especially evident with regards to world-building, where the author doesn't shy away from carefully building it up in a believable way). It is also extremely well-written and very long, having over 756k words at the time of this writing. Another thing this fic does well is characterization, with personal development and struggles being depicted with care and consistency (especially with regards to Emiya, though certainly not limited to him).
  • Now with its own Tropes page.

The Marker by Faust23
  • Recommended by: GrantMK2
  • Crossover with: Dead Space
  • Status: Dead
  • Synopsis: Lured away from her research on the protheans, young archaeologist Liara T'Soni joins an expedition to an unexplored part of space. There, a ruined world and a derelict ship hold secrets that may explain the cause of the prothean extinction or may be the harbinger of their own.
  • Comments: A well written crossover with Dead Space about Liara working with a team to investigate the mysterious USG Ishimura. Set before any official first contact with humanity, it gives a fresh view from nonhuman characters, avoids the usual cliches and even manages to make Saren competent if not likable.

Mass Effect: Clash of Civilizations by Eterna1Soldier
  • Recommended by: Meta Skipper, MetalKing1417, Red-Dead-Redeemer
  • Crossover with: Halo
  • Status: Dead; last updated May 2016
  • Synopsis: In 2157 a Citadel Council exploratory vessel is tasked with opening a dormant Relay into unknown regions of the galaxy. What they find is something they never expected. What happens when two civilizations centered around different technologies clash?
  • Comments: This fic explores well the implications of two cultures meeting. The characters have stayed true, and the OCs are well-fleshed out. The space battle scene is also written well, being more than one side has bigger guns, hence they win. Overall, a well-written fic, though the author's long update times are to be noted.

Mass Effect: Dishonored One by The Last Order
  • Recommended by: VictorioMWolff-Haddock
  • Crossover With: Dishonored
  • Status: Dead; last updated February 1st, 2013
  • Synopsis: Commander Shepard discovers one of Cerberus's greatest secrets and learns the universe is more complex than she thought. Now she prepares for war but she is not alone. The dishonored one fights with her and the outsider guides them. The galaxy will never be the same after they are done with it.

Mass Effect: Human Revolution by IgnusDei
  • Recommended by: Kalaong, GoneRampant, Zaptech, Poptard, PNG, Minty Fresh Death
  • Crossover with: Deus Ex
  • Status: Ongoing
  • Synopsis: The empty years between the present day and the discovery of the Prothean Ruins on Mars are filled in with the three Deus Ex games... and end with anti-aug fanatics in control. Humanity is a bioconservative shadow of its canon glory. But fear not, Honest Corporate Executive David Sarif saw it all coming, and preserved his technology, researchers, himself, and Adam Jensen as Human Popsicles. Unfortunately, after more than a century on ice, only Adam made it to the 2170's — and barely makes it off Earth ahead of the torch-waving Muggles. But even off-world, Adam just can't stay out of trouble he never asked for. His first attempt to put down roots is on Elysium, and only his (suppressed!) rescue of the colony from batarian raiders enables him to leave the planet intact. He seems to find a home on the Citadel itself, distinguishing himself as Garrus Vakarian's partner in C-Sec. Only Commander Shepard, fresh from the attack on Eden Prime, gets herself assassinated hours after she sets foot on the Citadel. Adam Jensen never asked for this, but someone has to stop Saren — and he's better equipped than anyone else in the galaxy to do it.
  • Comments: Conspiracies, cyborgs and snark hit the Mass Effect universe hard enough to knock out a charging krogan. The author is a transhumanist who was disappointed with Mass Effect 3's endings, and has chosen this combination of extropian promise and old-fashioned badass to set it right. Prepare for asari terrorists taken out with thrown fridges, naive sentinels driven to distraction with CASIE mods, and krogan sucker-punched by inert ultra-tensile carbon fists. Be warned that it takes a while to get into gear, though, so try to stick with it at least four chapters. Also, IgnusDei was personally involved with the development of DX:HR — at least to the point of having designed several set pieces.

Mass Effect New Origins V2 by erttheking
  • Recommended by: drsdino
  • Crossover with: Halo
  • Status: Complete
  • Synopsis: On the dawn of the 27th century, the UNSC discovers a Mass Relay, and unlock its power. What follows not only includes making contact with new species and making new friends, but making new enemies as well, and the entire galaxy will shake.
  • Comments: An interesting fan fiction, has some typos and very long Author Notes that boil down to either swear ridden ranting, or odd tangents that descend into babbling. But it has interesting characters, character development. And best of all?... NO STAR CHILD HURRAY!
    • Sithking Zero: Ertheking is a good author... but his stories can get slightly predictable at times. He dislikes the Citadel for several reasons, and he hits them in pretty much each story: the Genophage, the Quarians, and AI's. The earth governments are superior to the citadel in terms of some form of tech, and have the moral high ground while the Citadel squirms. He has gotten better, and he can write very convincing characters. I would say to skip this one and go to one of his more recent projects, "From the Ashes," which is a Fallout/Mass Effect crossover.
    • Mickey Moose: Personally I don't find him to be a good author at all. Or rather, while he's got some talent as a writer, he fails as an author. A lot of the "story" he writes isn't a story at all, but is rather an extended timeline with vignettes interspersed in between timeline entries. All told, his work reads like the bastard child of an encyclopedia and a short-story-filled fiction magazine.
    • YatNami: While the author is good at world building, he is not very good at writing dialogue or character interaction. That issue is present here, but thankfully its toned down compared to his other works. I would recommend it if you like stories with solid world building, but if you looking for good character interaction, I would fine a different story.

No Gods, Only Guns by Peptuck
  • Recommended by: MetalKing1417, Zaptech, USA Bobcat, DigitalPatriot
  • Crossover with: Borderlands
  • Status: Dead
  • Synopsis: Ancient artifacts of immense power. Murderous synthetics. Ruthless megacorps. Unscrupulous mercenaries. Genocidal stellar god-machines. Incompetent galactic governments. Claptrap dubstep. The horrors of the galaxy are many, but there's one thing a good, mentally-unstable fortune-seeking antihero can rely on: the gun at his, her, or its side. Mass Effect/Borderlands fusion.
  • Comments: First off: Udina with an eye-patch and cyberarm! On a more serious note, the story is another fusion by Peptuck that combines Borderlands' general batshit insanity and over-the-top humor with the interstellar political drama and impending apocalypse of Mass Effect, with Lilith replacing Shepard.
    • DigitalPatriot: Definitely gotta recommend this. The author manages to combine the characters and atmosphere of both Mass Effect and Borderlands 2 near perfectly, while changing events up enough for it to be a true fusion, rather than just another "retread of Mass Effect with someone else in Shepard's Place". Also, I will see your Udina and raise you Torgue Urdnot.

Paradigm Shift by SemaphoreRaven
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Dishonored
  • Status: One Shot
  • Synopsis: The Outsider is a jerk, communication issues are resolved, a game of chess is played, some pirates have bad timing, and Corvo acquires a shotgun.

Parallel Processing by Fluoxetine
  • Recommended by: Doctor Fluffy
  • Crossover with: Titanfall 2
  • Status: Ongoing
  • Synopsis: Years and years after the events of Titanfall 2, the Frontier Militia has defeated the IMC, reorganizing itself as the Systems Alliance, spreading from world to world. However, the Systems Alliance soon finds itself in contact with a new enemy — the mysterious group known as Cerberus. Things become even more complicated, however, when the Systems Alliance Armed Forces stumbles upon a Batarian slave-trading operation, and finds themselves on the galactic stage. However, there are mysteries in the background: Who, or what is Cerberus? What is the role of Titanfall's strange, time-manipulating Precursors in Mass Effect's well-known past?
  • Comments: Currently on a bit of a slow burn, not that the fans mind due to it thankfully averting Mass Effect as the Butt-Monkey of crossover fanfics, its focus on cultural clash, and worldbuilding. I don't mind, anyway.

Projects Magia and Lazarus by ffdrake
  • Recommended by: Kalvan
  • Crossover with: Dragon Age
  • Status: Dormant, last updated July 2015
  • Pairings: MHawke/Merrill, Male Shepard/Tali'Zorah, hints of one-sided Liara/Made Shepard and Ashley/Male Shepard
  • Synopsis: Cerberus thought they had found the key to human evolution once they stumbled upon two unlikely people wandering the woods lost and confused. Now the Projects meant to better humanity, Magia and Lazarus, might just the key to bring an end to Cerberus, the Collectors, and the Reapers.
  • Comments: Merrill's reactions to everything just have to be read to be believed. And her conversations with Tali crank both of their Adorkableness up to eleven. Be careful, though, it suffers from a major case of Rouge Angles of Satin.
  • Tags: Rated M, Sci-Fi/Romance

Psi Effect by Capn Chryssalid
  • Recommended by: Mangod
  • Crossover with: XCOM: Enemy Unknown
  • Status: Dormant (last update in June 2019)
  • Synopsis: A fun-loving asari mercenary finds herself a little in over her head when she ends up abducted by terrifying aliens from beyond the galactic frontier. These asari-like creatures call themselves 'humans.' They seem to be secretly nosing about on the borders of known space, acting through proxies, conducting covert operations, and they've got a deal for an enterprising asari...
  • Comments: A funny story about how OC Ilena Thanoptis, an Asari mercenary, gets dragged into being the public face of Eclipse, which is in reality a XCOM Black-Ops front for destabilizing the Batarian Hegemony and collecting information on the rest of the Citadel Races. The story is only six chapters long at time of Writing, but so far the story has managed to both be very funny (Ilena being a stereotypical vapid Asari maiden) and have some rather great action beats (Annabel Shepard's fight against Urdnot Wrex).
    • Story has gone a decent ways since then. While there are a handful of moments that are a little confusing with something being mentioned then immedietly jumping into a flashback with little explanation — after it happens a few times you get used to it. The current happenings (chapter 12) and the unfurling events surrounding Eclipses new allies are being handled very well in my opinion.

Red Alert: The Dawn of Man -- Redux by Tallman7
  • Recommended by: Tankred
  • Crossover with: Command & Conquer: Red Alert 2
  • Status: Dead
  • Synopsis: The end of the Soviet/Allied war came, but it didn't end the story. This is the story of how Humanity was finally united against a greater threat, and afterwards.
  • Comments: It details a scenario where the events that caused Red Alert 3 was averted by the Soviet Commander known only as "the Bear" (who turns out to be a woman), who upon realizing that Communism was a stupid idea and lacking any intentions of letting the war continue, defected to eternal rival and the Allied Forces' preeminent commander (known only as "The Eagle") with the Time Machine and a handful of loyal Soviets. Although the road turns out to be rocky and sometimes narrow (at one point requiring the Eagle and the Bear, now the political leaders of their respective factions, to blindside the whole world with a sudden announcement of their impending marriage in order to end the rapidly worsening Cold War), the Allies and the Soviets just barely end up getting along when faced with what is basically a light A.I. uprising. The story has an even progression rate, well-written and accurate characters along with good descriptions that makes it hard to put down.
  • Conclusion: If you didn't like how EA screwed up the Red Alert continuity any more than I did, and want to see the marriage of Allied and Soviet technology used against the Mass Effect races, this one is for you.

Red Alert: Mental Effect by Mental Omega
  • Recommended by: Varaxar
  • Crossover with: Command & Conquer: Red Alert 2 (Heavily borrows from the mod Mental Omega in particular))
  • Status: Revived with regular updates.
  • Synopsis: After the Soviets win in Yuri's revenge, Yuri is brought back by his last, most zealous followers from the Cretaceous and conquers the world; driving the Allies and Soviets to Mars. After a series of interplanetary wars that parallel the Tiberium saga culminating in the Scrin invasion, the Alliance; formed of the Allies and Soviets, leaves the solar system and forms its own state elsewhere. Many years later, the Citadel comes into contact with man's divided factions, and then things start getting strange.
  • Comments: With the exception of the hapless mooks, most everyone seems to be portrayed as reasonably competent and able. In a break from most mass effect A Us, there are actually two Shepards. Female shepard is portrayed by Catalina Cioban; an Epsilonist girl orphaned in a raid on her home world. Male Shepard is represented by Wolfgang von Schafhausen; an alliance N7 commando from a military family who's surprisingly sensitive for a military man. The story heavily features outright zany elements in ways only red alert can, with talking dolphins, guitar aficionado hulking cybernetic monstrosities, and is positively crammed with little references to not only Red Alert 2, but to just about every part of the C&C series, from the well known to the obscure and even a number of the more well known C&C mods. Familiar faces pop up in unexpected places, and the story is complemented by an extensive cast of new characters. It's definitely worth a look if you're hoping to see something a little different, and it does its best to avoid human wank. It's got sharp action, a great appreciation for scale, solid concepts and characters that are so far quite interesting.
  • Tags: M!Shepard, F!Shepard, Action,

Renegade by Peptuck
  • Recommended by: corin, USA Bobcat, Deep Recon
  • Crossover with: Command & Conquer: Tiberian Series
  • Status: Dead
  • Synopsis: A Mass Effect/Command & Conquer: Tiberian Series Crossover/Alternate Universe fic that replaces the Mass Effect Earth with Tiberium Earth, with GDI taking over the role of the Systems Alliance, that follows the plot of the original game. Female Colonist Sole Survivor/War Hero Shepard who appears to be a combination Vanguard/Adept. Not yet clear whether she's Paragon or Renegade.
  • Comments: Inspired by a discussion on Spacebattles.com.(Spacebattles story thread here.) Essentially serves as a novelization of the game that explores how different everything would be if GDI replaced the Alliance, and how their technology and Tiberium would dramatically influence politics, i.e. Nod intervenes in the slaver attack on Elysium, GDI goes to war with the Batarian Hegemony, the Scrin were behind Akuze and Eden Prime, etc. The story is still relatively new, however, so there's no idea when it will be updated.
    • My favorite fanfic of all time. And even if you don't know Command And Conquer, I have three words for you: Spectre Garrus Vakarian.
    • Definitely seconded. This isn't Mass Effect with GDI in place of the Alliance, it is a true mixture. Basic example: With the aggressiveness of GDI Foreign Policy, the Council expands the number of Spectres, leading to Spectre Garrus Vakarian, who the Author himself described as "Turian Jack Bauer meets the Kool-Aid Man."
    • Good fics are already hard to find, that much is well-documented. Good crossover fics is a contest of finding a minority group within a minority group, but Renegade is one of those wonderful few. There is a minor change in tone for readers going from chapter one to seven in one sitting (as this troper did), from rather dark 'n gritty to downright funny, but when the comedy is genuinely entertaining (good comedy fics being another minority among minorities), it's more than excusable. Well-worth the read. —Deep Recon
    • seems to be a dead fic as it hasn't been updated in several years. unless Peptuck is going to pull a Kane...

The Second Contact war by Mythicspider629
  • Recommended by: VictorioMWolff-Haddock, Red-Dead-Redeemer
  • Status: Ongoing
  • Crossover With: Call of Duty
  • Synopsis: After the battle for the citadel and Jane Shepard's death, the galaxy has finally begun to calm down, and, besides a handful of people, everyone has forgotten about the Reapers or chooses to ignore them. This makes things easy for the citadel council. And with the majority of the Normandy crew scattered throughout the galaxy, there is no one left to stop the Batarians from being stupid.

The Sins of our Fathers by MarkerMagnum (Ao3 Link)
  • Recommended by: VictorioMWolff-Haddock, Red-Dead-Redeemer
  • Status: Ongoing
  • Crossover With: Halo
  • Synopsis: Unknown to the Citadel Council, the Human-Covenant war nears its vicious end. Miranda Keyes is seconds too slow. Delta Halo fires, leaving UNSC space as a lifeless snapshot in time. The Citadel must mourn the loss of a civilization they never knew.
  • Comments: a unique Halo X Mass Effect fanfic where Earth has become barren and most of the UEG characters are the AIs.

Smoke, Sorcery, and Steel by A Very Thirsty Megalomaniac
  • Recommended by: VictorioMWolff-Haddock
  • Crossover With: Dishonored
  • Status: Dead; last updated October 1st, 2018
  • Synopsis: A long time ago, the Outsider formed. Contrary to many's beliefs, he could not change his face. When aliens saw him in their dreams, they knew humanity long before humanity knew them. And they feared. Now their space whaling routes cross paths, and the aliens stare upon humanity's face proper. And they fear. Perhaps rightly so. The Outsider only shrugs, and then offers his mark.

The Spartan Effect by Gatekeeper333
  • Recommended by: inferno1818, hunter 139
  • Crossover with: Halo
  • Status: Ongoing with monthly updates
  • Synopsis: Everyone's favorite Spartan is looking for a new purpose, lucky for him, the Commander his happy to oblige.
  • Now has a TV Tropes Page: The Spartan Effect
  • Comments: An excellent crossover between the Halo and Mass Effect universes and one of the best fanfictions I have ever read. This takes place during the events of Mass Effect 2 and the author does a very good job of integrating Master Chief and Cortana into the Normandy. All of the characters are true to the source materials with few liberties being taken. Gatekeeper333 has also done a great job of making Shepard one of the best written Shepards I have read in a long time by making him very sarcastic with a lot of depth. The author also has a writing style somewhat similar to The Hitchhiker's Guide to the Galaxy in the non-action scenes and does a great job with the comedy. The action scenes are all very well written with the exception of the first couple chapters. With the exception of the first couple chapters, this fanfic is amazing in almost every way.
    • Seconded: This is hands down the best “Master Chief and Cortana end up in Mass Effect” fic I’ve ever read. I daresay it’s even better than In the Shadow of Gods. The Master Chief’s characterization is on point, as is Cortana’s and the rest of the Normandy crew. There are some issues of course; the Terry Prachett writing style can be rather distracting at times, and personally, I think Master Chief is somewhat quieter than he really should be. But character interactions drive the heart of this story, and the Spartan Effect has enough differences to make up for it, including an excellent portrayal of Cortana’s rampancy and most recently Master Chief’s loyalty mission where the Normandy crew has to deal with a colony overrun with Flood that had stowed away on the Dawn.
  • Tags: M!Shepard, Action, Mass Effect 2*

Spectre ga Gotoku | Mass Effect Kiwami 2 (Substory 27: Krogan Sushi) by al_fletcher
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Like a Dragon
  • Status: One-Shot
  • Synopsis: What if sidequests in Mass Effect worked like the ones in Yakuza?

Stars Fade by totallybursar
  • Recommended by: USA Bobcat
  • Crossover with: Dragon Age
  • Status: Dormant (last updated June 2017)
  • Synopsis: Shepard knows that destroying the Reapers will kill her. Except she's never been good at dying. The explosion of dark energy from the Crucible thrusts Shepard into a totally different universe. Post ME3 ending, DA2 Act 2 beginning. (FF.net Description)
  • Comments: A crossover with the Dragon Age series. Shepard just can't catch a break, though luckily her omni-tool still works. She's not happy with the slavery that mages endure, or the fact that she's attracted the interest of the Qunari. But more importantly, there are no toliets! It's a throughly engaging read that brings to life the realities of the Dragon Age series without losing any of the appeal.

Starwatch by CruxMDQ ([[Ao3 Link)
  • Recommended by: ZeroDead, TwixTrix
  • Crossover with: Overwatch
  • Status:
  • Synopsis:
    • Starwatch - A young Alliance Navy lieutenant is given the mission to reopen a long forgotten vault on the Moon - and can only witness how Reaper is accidentally unleashed into a universe where humanity is about to find out that it is not alone.
    • Starwatch: Compact - After the battle of the Citadel and Sovereign's defeat, the Citadel Spectres and the Alliance agency that succeeded Overwatch must pick up the pieces and gear up their efforts to prepare for the looming threat, while also dealing with the inertia of their parent governments, the machinations of shadowy forces, and competing initiatives.
  • Comments: This project so far spans two arcs, the first one being about the First Contact War and taking place some thirty-odd years after the events of Overwatch, and the second one roughly happening at the same time Mass Effect unfolds. The writing style follows the ME dynamic, with heavy character development and interludes between combat missions. Of note are Reaper's and Tracer's characterizations and evolution as the story unfolds.
    • Synopsis: After the battle of the Citadel and Sovereign's defeat, the Citadel Spectres and the Alliance agency that succeeded Overwatch must pick up the pieces and gear up their efforts to prepare for the looming threat while dealing with the inertia of their parent governments, the machinations of shadowy forces, and competing initiatives.

Sudden Contact Series by A Very Thirsty Megalomaniac.
  • Recommended by: Nederbird
  • Crossover with: StarCraft
  • Status:
  • Synopsis:
    • Sudden Contact - The Protoss and Turians make violent first contact after the former accidentally chase a Terran scavenger through a previously dormant Mass Relay in the Sara system. A few turians end up on the Koprulu side of the relay and emergency-land on Mar Sara, encountering both terrans and the invasive Zerg. The war in the hitherto isolated Koprulu sector soon spills over into Citadel space, pulling the rest of the galaxy into a three-way war between the zerg on one side, the terrans, protoss, and Citadel races on a second side, and Sovereign and his geth on a third side.
    • Sudden Supremacy - The UED is here. Magnificent and relentless, they march forward in defiance of the watching darkness. On the edges, the only person with both the knowledge and means to stop what's coming remains wracked with doubt, at war with her nature. Jim Raynor, meanwhile, struggles onward in a galaxy that has outgrown him. Sequel to Sudden Contact. Complete.
    • Sudden Terminus - The end is nigh. The outcome is uncertain.
  • Pairings: Raynor/Kerrigan; later Raynor/Miranda, Kerrigan/Garrus, Tychus/Jack, and Nova/Saren.
  • Tags: Fusion Fic; Fix Fic; Original Flavour; Switching P.O.V.; Alternate Universe (for humanity only: the colonies are the Koprulu terrans while Earth is the UED); plenty of Deconstruction too, though that is not a primary characteristic.
  • Comments: Point of View is divided between multiple characters from both franchises, whose numbers skew heavily in favour of StarCraft in Sudden Contact but is balanced in the sequels. The fic starts at the beginning of both games' storylines and is interwoven instalment-to-instalmentnote  in such a seamless and lore-friendly manner that it feels as if they had always been one and the same. The author endeavours to present most characters as true to their canon personalities as possible, except where he nuances antagonists such as Mengsk, Udina, and Arterius into something less cartoonish, where they still preserve their canon traits as flaws in a more complex personality. The fic presents the races at varying degrees of parity with each other: the terrans, the UED and the Council species are roughly at part with each other, with each side having some technologies that are superior to the others', while the zerg and protoss vastly outmatch the others... at the outset.

The Sword of the Geth by DoctorpooandtheTURDIS
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Halo
  • Status: Ongoing
  • Synopsis: Dying on Mantle's Approach, Cortana wakes up in an unfamiliar environment. In her drive to get home, she 'employs' the assistance of the local synthetics. Very quickly, however, he plan goes off the rails, with a looming galactic threat, and the local organics' own fear of her kind. She never wanted to be a galactic overlord. But a UNSC AI in an environment woefully unprepared for one of her caliber makes an easy one.
  • Comments: Cortana allies herself with the Geth to find a way home and help their public image. oh, and Cortana is given a 12-foot humanoid Geth Prime for a body.

Terran Ingenuity (FF.net link) by Xeno Major
  • Recommended by: SAMAS, GreatLimmick
  • Crossover with: Starcraft II
  • Status: Dead
  • Synopsis: Sometime after the events of Wings of Liberty (and possibly Heart of the Swarm), James Raynor decides to quit the Korpulu Sector altogether, eventually settling down on Shanxi with whoever wants to come with him. When somebody discovers the huge relay in the system, you can guess what happens next. Everybody involved is in for some big surprises.

There Is Always Some Kind of Way Out of Here by The Archaon
  • Recommended by: VictorioMWolff-Haddock
  • Crossover with: Watch_Dogs
  • Status: Dead; Last updated November 6th, 2014
  • Synopsis: Aiden Pearce has never been a man to give up, and when he finds himself surrounded by Blume troopers, he does his best to give them one last black eye. This sets off a series of events, landing Aiden in a new world. Some things, however, never change, and now the Illusive Man has sent Shepard to 'deal' with a little problem, a little problem know as 'The Fox.'

Thirty Seconds Flat by Fluoxetine
  • Recommended by: Gentlemens Dame 883
  • Crossover with: PAYDAY: The Heist
  • Status: Dead; thread last updated February 2016
  • Synopsis: The Reaper War is 250 years in the past now, but peace on the Citadel is once more threatened, this time by a group of disturbingly competent criminals with a mysterious backer.

United We Stand by Mayto
  • Recommended by: Red-Dead-Redeemer
  • Crossover with: Halo
  • Status: Dormant; last updated June 5, 2021
  • Synopsis: Starting off at the height of the Human-Covenant War during the battle of New Ghent: just as the local UNSC forces are losing to the Covenant, drop pods of unknown origin appear. These troops soon reveal themselves to be aliens, but not of Covenant races, and even more surprising to the combatants, begin fighting the Covenant to assist the humans.
    The Citadel intervenes in the Human-Covenant War.
  • Comment: A crossover that isn't just yet another First Contact War, "Humanity Fuck Yeah!", roflstomp.

When There Was a Tomorrow by General Rage
  • Recommended by: Lord Gale, Crow T R0bot, USA Bobcat
  • Crossover with: Halo
  • Status: Complete
  • Synopsis: Halo/Mass Effect. Takes place Post-ME2 and Shadow Broker DLC. Noticing an anomoly out in the far reaches of space, Shepard takes the Normandy crew in to investigate. "Just Recon," is all. Until they find a wormhole that reads similarly to Reapers, with Covenant ships pouring out of it. The Author ships Shepard/Tali.
  • Comments: Despite many a spelling error, this is amazingly well written. The characters are all faithful to the source material, both the Mass Effect AND Halo characters. This story is better appreciated if you've read the Halo Novels, but even if you haven't it's highly reccomended. The firefights are exciting, the drama intense, and the humor well written. The story updates slowly, due to the sheer SIZE of the chapters — at LEAST 20k per chap, if not MORE.
    • Eh... YMMV. The blatant exposition, and the fact that Shepard suddenly speaks like a native of the southern United States might put people off. It is quite grating whenever I read Shepard asking if "He can help ya out."

XCOM: Second Contact (FF.net link) (Thread on spacebattles) by Agayek
  • Recommended by: Mikemerc, USA Bobcat, Unclouded TJ, Stormedge
  • Crossover with: XCOM: Enemy Unknown
  • Status: Extended Hiatus
  • Synopsis: With the destruction of the Temple Ship humanity knew peace. XCOM never forgot their motto however, 'always vigilant, always reliable'. Loosely follows the plot-line of the original game with new characters and relationships.
  • Comments: X-Com humanity replaces the Systems Alliance. The Galaxy will never be the same.

    Web Animations 

The Reaper Summer by Helljumper206

  • Recommended by: Tropers/Vinnymoneyho
  • Crossover with: RWBY
  • Status: Ongoing (Last updated May 2021)''
  • Synopsis: For as long as she could remember, Summer had been fighting. Not remembering her past before her service to humanity and the galaxy at large. With the threat of the Reapers about to be dealt with once in for all, images of a time before appear. A/N: Commander Shepard is Summer Rose. (FF.Net Description)
  • Comments: An interesting take on if Femshep is Summer Rose. There is an extremely heartwarming scene where she reunites with the rest of her family, which brings tears to my eyes. Outside a few grammar mistakes, it's well written. And we see Ace-ops learning why you don't mess with an N-7 operative who is also a biotic.
    Western Animations 

Avatar of Victory by James Golen

  • Recommended by: Tikigod784
  • Crossover with: Avatar: The Last Airbender
  • Status: Complete
  • Synopsis: A blend of the Avatar and Mass Effect universes in that the Earth of A:TLA replaces our Earth. What this means for the universe besides Shepard being the Avatar is that Bending is a present and practiced phenomenon among all the races of the Citadel as well as the presence of spirits and certain other aspects of the Avatar universe. Interesting not just because of the crossover itself but because it shows an Avatar who is fundamentally broken and has spent most of her life (including parts of this story) making things worse for herself rather than the spiritual growth that we've seen the other Avatars go through. Fight scenes are excellent and detailed, with most enemies that Shepard faces being competent, and not just because some of them are better at bending then she is. Canon names being included in regard to humans actually does get explained so don't let that throw you off.

Ben 10 Mass Effect Crossover by Parker_Fox
  • Recommended by: VictorioMWolff-Haddock
  • Crossover With: Ben 10
  • Status:
  • Synopsis: Ben Tennyson finds himself in the Mass Effect universe shortly before the start of the second game.
  • Comments: This has scratched the itch I have with Ben 10 being isekai'd to Mass Effect world, with the teen hero helping the Normandy team's moral compass stick harder on Paragon. While Omnitrix is nerfed by being a bit glitched after being temporarily modified by Skurd, it merely forced Ben to be more creative. One of this fic's flaws is that, unlike most Ben 10 fanfics, it still addresses Ben as Ben instead of his alien form's name after every transformation, while spending a paragraph on the transformation scene.

Records of an Irken Defective by KiwiDayDreams
  • Recommended by: Lord Gale
  • Crossover with: Invader Zim
  • Status: Dead
  • Synopsis: Mass Effect/Invader Zim. A post-ME2 fic, in which (fem)Shepard is called to Earth to investigate a mysterious death in an old abandoned house, only to confront some sort of deranged, psychotic robot. The fight escalates, and they stumble upon a stasis pod containing a certain green Invader, asleep since the year 2025...
  • Comments: This story begins as comedy, with a bit of ingenious series-mixing here and there, and great characterization typical of good Mass Effect fanfiction until we arrive at the fate of the rest of IRK. This fic is not the bright and happy crossover this troper expected in the slightest, but then again, given the source material... regardless of how horrifying it was for this troper, this is a very intriguing and well written fic, and if you have the stomach to watch Tali nearly drown, then by all means, read it.

Shepard's R&R by ed2481 and Loyal2Luna
  • Recommended by: Reterusu, Poptard
  • Crossover with: My Little Pony: Friendship Is Magic
  • Status: Indefinite hiatus
  • Synopsis: Commander Shepard awakens from his coma after surviving the near-destruction of the Catalyst. His extended sleep was all the rest he was getting, as the galaxy has discovered a mysterious new race of equines with mysterious powers. With the help of his old companions, Ambassador Shawn Shepard journeys to the planet Equus to make sure the Equestrian's welcoming to the galactic community goes as smoothly as possible... and secure the Serenity system's resources for the Council.
    Multiple Crossovers 

Hunters of Death by DesertChocolate

  • Recommended by: Infinite Freedom 01, Omeganian, Mikeal52, MetalKing1417
  • Crossover with: Pacific Rim, Godzilla
  • Status:
  • Synopsis: Decades after the sacrifice of Gipsy Danger, a hopeful mankind looked to the stars. With a army of Jaegers in tow. Now, decades later, the Normandy SR-1 is sent to Eden Prime, and The Shepard Twins, one raised on Earth, the other in space, prepare to show the universe what they're made of. Because sometimes, it takes monsters to kill monsters.
  • Status: Rewrite]] started.
  • Comments: Though Jaeger battles don't happen too often (Mainly due to them being a bit unwieldy for the average Mass Effect fight) the influence of their existence is clear from the moment the teams hits the Citadel, mainly the ripple effect caused by a humanity using Jaegers. The story has more to do with Mass Effect with giant robots, but a fun show for fans of both the movie and the games. Now with flying Jaegers and biotic Kaiju!

Magnificent Scoundrels by thelordofdarkreunion
  • Recommended by: VictorioMWolff-Haddock
  • Crossover With: Halo, Titanfall, Ciaphas Cain, Star Trek: The Original Series, Star Wars, Marvel Cinematic Universe
  • Status: Ongoing
  • Synopsis: When galaxies collide, the greatest heroes from each team up. The question is not if they can survive this strange new reality, but rather if this new universe can survive them.
  • Comments: Multiple universes are merging, and the only ones who can save it are the crews of Normandy, Master Chief & Cortana, Ciaphas Cain & The Valhallan 597th, Hans Solo & Chewie, Jack Cooper & BT- 7274, and Guardians of The Galaxy.

Mass Foundations by Nord Ronnoc
  • Recommended by: Ameriken
  • Crossover with: Fallout, Doctor Who, Soul Series.
  • Status: Ongoing
  • Synopsis: There are universes that diverge from a choice and there are universes that are fundamentally different from one another, forming a vast, limitless multiverse. In these set of universes, there are orbs that manipulate and alter any reality, rip apart the boundaries between them. If left unchecked, they will bring an end of everything. Welcome to the multiverse. Enjoy your stay.
  • Comments:
    • Unlike most fanfics, it's actually well-written. It's consistently interesting, too. As far as crossover fan fiction goes, this one is definitely worth a read.

Screw This, I'm Firing the Halo Array
  • Recommended by: Pantegral
  • Crossover with: Halo, The Hitchhiker's Guide to the Galaxy, Star Wars, Star Trek: The Next Generation, BioShock, Harry Potter, StarCraft, Alien
  • Status: Dead
  • Synopsis: It's the end of Mass Effect 3, and it sucks. Luckily, new universes come to the rescue! Complete and utter crack.
  • Commments: The first two chapters are just your typical silly crack fic. From the third chapter onwards, however, the story shifts into an incredible awesome take on what would have happen if ships and people from a dozen different universes were dumped into the Battle of Earth's final stages. Probably the best ME mega-crossover I've read so far: the writing is actually good, and the story doesn't take itself too seriously — the butchered riffing of the Arbiter's trial in Halo 2 has to be read to be believed.
    • Hero2014: I agree with everything said above, especially the well written bit. It's interesting seeing the evolution of this story. The first two chapters are legitimately just crack, but from the third chapter on it starts an actual story arc, throwing just about every fictional universe it can into the final battle against the reapers. A cracky concept, yes, but the author actually explores it logically, making for a remarkably gripping read, especially the sixth—and unfortunately last—chapter. If nothing else, it's worth reading for sheer novelty.

The Supernovas of Mass Effect by Blindluck92
Vigil (Fanfiction.net link) by Peptuck
  • Recommended by: Zaptech
  • Crossover with: XCOM: Enemy Unknown/First Encounter Assault Recon/Eclipse Phase/Destiny (plus other settings according to Word of God)
  • Status: Dead; last updated September 2016
  • Synopsis: Mankind has survived its crucible, and while scarred and changed by the Ethereals, they advance into the cosmos. The galaxy beyond is a place of wonder and terror, of wealth and strife. Amid the threats and opportunities, both within and without, XCOM remains vigilant.
  • Comments: A Fusion Fic similar to XCOM: Second Contact, where XCOM humanity exists in the Mass Effect setting. Unlike most crossovers, the setting integrates other aspects of other franchises, like FEAR and Eclipse Phase technology. Also averts The Stations of the Canon, as First Contact happens in 2103 with the geth and things spiral out from there.

Voyage unto Infinity by supertruckin
  • Recommended by: VictorioMWolff-Haddock
  • Crossover With: Halo, Star Trek: Voyager
  • Status: Ongoing
  • Synopsis: The USS Voyager comes face to face with the massive ship that is the UNSC Infinity after Voyager's nearly fatal first test of their quantum slipstream drive. Getting home isn't their only issue. They will have to work together in order to unravel the ancient threat that plagues the new galaxy that they find themselves in.

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