* AscendedFanon: It was a common enough trope in ''Mass Effect'' FanFic to have ''both'' John and Jane Shepherd as protagonists, usually depicted as a BrotherSisterTeam. [[note]] This originated from ''VideoGame/KnightsOfTheOldRepublic'' fandom where two Revans were used as a nod to the Skywalker twins, and a way to have both the canonical male Revan and the fan-preferred female Revan [[/note]]. What's ''VideoGame/MassEffectAndromeda'' got on the character creation screen? Yup. Ryder has an opposite-sex twin that you customize in the same way.
* BannedInChina: For about two days in Singapore.
* BeamMeUpScotty: Shepard's flirting can be cringeworthy, but s/he never says "We'll bang, okay?" in-game. That quote originated from a Youtube Poop that mashed together several Shepard lines out of context.
* CanadaEh: Believe it or not, both Shepards Voice Actors are Canadian. While Jennifer Hale is fairly good at hiding the accent, Mark Meer tends to fall into saying "Aboot" every once and awhile.
* CashCowFranchise: Four novellas, two comics (plus two free mini-comics), and three spinoff [[IOSGames iPhone]] games, so far.
* CelebrityVoiceActor: ''All'' over the place. Creator/SethGreen, Creator/AdamBaldwin, Creator/YvonneStrahovski, Creator/TriciaHelfer, Creator/MartinSheen, Creator/ClaudiaBlack, [[Film/TheMatrix Carrie-Anne Moss]]... the list goes on. In fact, it could be said that the in-development movie could very well be made with many of the characters literally being played by their voices (in fact, FanDumb might result if anything else were to happen in some cases!)
* DoingItForTheArt: [=BioWare=] had an entire animation team ''just for eyes''.
* InspiredBy: Mass Effect's technological aesthetics, particularly of the omni-tools and Alliance armor, were heavily influenced by box office bomb Anime/FinalFantasyTheSpiritsWithin. The game's art director was a big fan of the movie's style.
* LongRunners: Ten years and counting. The series started in either November 2007 with the release of the first game, or May 2007 with the release of the first novel and lore guide, and it was still receiving new content (in the form of MP DLC) by at least December of 2017, with [[https://www.dailystar.co.uk/tech/gaming/639235/Mass-Effect-Andromeda-DLC-BioWare-release-date-Dragon-Age-Anthem plans]] for at least one more main game. Since then the series has had four main games (''1'', ''2'', ''3'', and ''Andromeda''), two more-or-less independent multiplayer modes with their own mechanics and extensive unique content (for ''3'' and ''Andromeda''), and roughly 25 hours of single-player DownloadableContent missions with their own stories. Other content includes 7 novels, 2 GaidenGame IOS titles (''Infiltrator'' and ''Galaxy''), 8 comic book miniseries (rather short ones though), and a straight-to-DVD animated film (''Paragon Lost'').
* RelationshipVoiceActor: Almost example, as Mark Meer ([=MaleShep=]) is married to Belinda Cornish, who voices Rana Thanoptis, the asari scientist who shows up on Virmire and has a minor role in the next two games. Don't forget that, in the first game, [[HarsherInHindsight Shep has the option to ''shoot'' Rana]]. [[spoiler: Turns out she was indoctrinated anyway.]]
* TheWikiRule: [[http://masseffect.wikia.com/wiki/Mass_Effect_Wiki The Mass Effect Wiki]].
* WhatCouldHaveBeen: At one point, it was going to be possible to [[spoiler:save both Kaidan and Ashley. This was removed when the developers realized no one would want to go on to further games with one of them dead if given the option]].
** When Creator/DrewKarpyshyn was still attached as head writer, the Reapers' motivation was originally linked to the buildup of dark matter in the galaxy from overuse of eezo; hence the strange readings from Haestrom's sun in ''Mass Effect 2'' (see AbortedArc). Their rationale was going to be that the energy can't accrue if there's nobody in the galaxy advanced enough to make it. When Karpyshyn was re-assigned to ''VideoGame/StarWarsTheOldRepublic'' after ''Mass Effect 2'', the new writers instead went with [[spoiler: the general conflict between organics and synthetics]] we see in ''Mass Effect 3''.
* WritingByTheSeatOfYourPants: Different interviews with writers across the series reveals that many things about the series' overall plot and some bits of lore was more or less constantly in flux and changed around quite a bit as members of the writing team were added or left (most notably the lead writer for the first ''VideoGame/MassEffect1'', Drew Karpyshyn, left around half-way through the production of [[VideoGame/MassEffect2 the second game]] and was replaced by Mac Walters). According to interviews in the interactive documentary about [[VideoGame/MassEffect the third game]], ''Final Hours'', the (quite controversial) ending was not decided upon up until a few months before the game's release.