* ActorAllusion:
** The krogan are very similar to [[Franchise/StarTrek Klingons.]] It's no surprise then that Wrex's adviser Gatatog Uvenk is voiced by an actor [[Creator/MichaelDorn famous for playing a Klingon.]]
** Kal'Reegar, the quarian you meet before facing the Geth Colossus, concerns himself less with politicking and more with shooting, just like [[Series/{{Firefly}} another character]] played by Creator/AdamBaldwin.
** Miranda, the Cerberus FemmeFatale, is voiced by (and modeled after) Adam Baldwin's co-star from ''{{Series/Chuck}}'', Yvonne Strahovski, who plays Sarah Walker, a CIA FemmeFatale.
** Creator/SteveBlum plays a strong, deadly, artificially created, technically newborn lizard warrior with a childlike ([[ValuesDissonance for his species]]) demeanor, a love for battle and an undying loyalty to his human master. [[Anime/DigimonTamers Curious]].
** Mordin's actor really did [[TheCastShowoff perform]] Creator/GilbertAndSullivan.
* AscendedFanon: BioWare's response to Garrus' and Tali's popularity and the fans' desire to have them romance options.
* FanNickname:
** The game that gave birth to Garrus being called Space Batman.
** [=SuZe=] was Jack's nickname before people knew it was "Jack". Short for "''Su''bject ''Ze''ro". It's fallen out of use now, probably because hardly anyone in the game calls her "Subject Zero." [[BerserkButton For good reason.]]
* HeyItsThatVoice: Tons!
** Grunt, [[spoiler:the Shadow Broker]], and Wilson are voiced by Creator/SteveBlum, albeit the first two being [[http://www.youtube.com/watch?v=dUrnu245Kas slightly altered]].
** Jack is Damsel from ''VampireTheMasqueradeBloodlines'' and Juhani from ''VideoGame/KnightsOfTheOldRepublic''.
** Miranda is Creator/YvonneStrahovski, best known as Sarah Walker from ''Series/{{Chuck}}''.
** Zaeed is voiced by Creator/RobinSachs.
** Legion is Creator/DCDouglas.
** In the Admiralty Board: Shoreh Aghdashloo, Martin Jarvis, Simon Templeman, and Creator/ClaudiaBlack.
** Kal'Reegar is Creator/AdamBaldwin.
** Captain Bailey is Michael Hogan.
** EDI is Tricia Helfer best known as Number Six in ''Series/BattlestarGalactica2003'' (and known as the Black Cat in ''WesternAnimation/TheSpectacularSpiderMan'').
** (Female) Shepard, voiced by Creator/JenniferHale is also known as the Black Cat, from ''WesternAnimation/SpiderManTheAnimatedSeries''.
** Liara is voiced by Creator/AliHillis, [[RuleOfThree and also known as]] Black Cat in ''VideoGame/TheAmazingSpiderMan''.
** Illusive Man is voiced by Creator/MartinSheen.
** Kelly Chambers is Alice De Raey from ''ThisIsWonderland''.
** Aria is Trinity from ''Film/TheMatrix''.
** Aethyta and Admiral Xen are voiced by Creator/ClaudiaBlack.
** Gavin Archer and Admiral Han'Gerrel are voiced by Simon Templeman ([[VideoGame/LegacyOfKain Kain]], [[Franchise/DragonAge Loghain]]).
** Patriarch and Wreav are voiced by Creator/JimCummings.
** Creator/KeithSzarabajka is Harbinger.
** Creator/MichaelDorn is Gatatog Uvenk.
** Creator/CindyRobinson is Detective Anaya.
* MemeAcknowledgment: Creator/BioWare merchandising produced shirts for the "Sir Isaac Newton is the deadliest sonofabitch in space!" and "I'm Commander Shepard, and this is my favorite store on the Citadel" memes.
* TheOtherDarrin: The voice for the man trying to get a refund from the turian shopkeeper on the Citadel doesn't sound '''anything''' like it did in the first game. If he didn't specifically mention that he'd been trying to get a refund for two years, most players probably wouldn't have noticed it was him.
* PlayingAgainstType:
** Creator/MartinSheen as the Illusive Man.
** Carrie-Anne Moss as [[TheDon Aria]].
*** Though... acting cool and sarcastic in a nightclub while she waits around for Our Hero? [[TheMatrix Not much of a stretch.]]
** Kal'Reegar is a much more open-minded, upstanding character than some of Adam Baldwin's more notable roles, standing in sharp contrast to ''Chuck'' and his parts in the Whedon universe.
* RelationshipVoiceActor:
** [[Creator/AdamBaldwin Kal'Reegar]], [[Creator/YvonneStrahovski Miranda]], and Aria are [[Series/{{Chuck}} John Casey, Sarah Walker, and Gertrude Verbanski]].
** EDI and Bailey are [[Series/BattlestarGalactica2003 Number Six and Colonel Saul Tigh]].
* SerendipityWritesThePlot: Many characters, especially [[spoiler: Legion]], have dialog for missions that happen long before you are able to recruit them. It's speculated that the game was originally much more open when it came to recruiting people and the space limitations of the Xbox 360's DVD drive forced BioWare to break things up.
* StarMakingRole: Legion is one of two roles that made a star out of Creator/DCDouglas, the other being [[VideoGame/ResidentEvil5 Albert Wesker]].
* ThrowItIn: Michael Beattie, Mordin's voice actor, came up with the idea of [[VerbalTic sharply breathing between sentences.]] It's now considered one of Mordin's defining characteristics.
* WhatCouldHaveBeen: The ''Mass Effect'' Wiki has a [[http://masseffect.wikia.com/wiki/Mass_Effect_2_Cut_Content comprehensive list.]] Some examples:
** Cut content from the Firewalker DLC [[http://youtu.be/9TSBIdOktfE reveals]] that one of the scientists you're trying to find was a minor NPC from the first game on Eden Prime, the one who was "raving".
** Unimplemented content, pre-release posts on Weekes's dev blog, and other leaks indicate that Tali, Miranda and Thane could be romanced by Shepards of either gender in earlier development. In the final product, the most visible remainder of this is that most of Tali's lines are the same for both Shepards, which are clearly intended to nudge the player to a romance with her. Female Shepard can even attempt to initiate a romance with Tali, but she will dodge the issue.
** Similarly, Kenneth and Gabriella were meant to be romanceable like Kelly.
** Character recruitment was originally intended to be much more open-ended, and modding your save file to add party members before you should be able to recruit them will let you hear their dialog for earlier circumstances, such as taking Legion to Purgatory. This likely changed because of the late decision to split the Xbox 360 version of the game into two discs; the forced recruitment progression funnels the player along a path that's not entirely linear, but predictable enough to split the game with.
** A few leftover voice recordings in the released game indicated that Liara was initially intended to have a much deeper and longer storyline which was later made a reality with the DLC Lair of the Shadow Broker.
** Early video previews showed more involved gun mechanics; weapons would cool down on their own la the first game, with ejectable thermal clips as a "need More Dakka right this second" option. Specialized ammunition was shown to be a consumable resource instead of a passive ability and as such could be turned on or off at will.
** Going through the dialogue and screen text files reveals that several of the loyalty missions originally had very different plots:
--->''"Bored with being the galaxy's top bounty hunter, Zaeed's also exhausted by up-and-comers seeking a rep written in his blood. Now he's learned that the second-best bounty hunter has gone corporate, and job one is to kill Zaeed. Zaeed's plan: wipe them out first... with extreme prejudice."''\\
''"You helped Zaeed fake his own death, and he's grateful."''\\
''"Kasumi revealed that Nava Corp has designed and is about to unleash tailored bio-viruses against the citizens of the Alliance. Only Nava Corp possesses the vaccines. Kasumi needs you to help stop Nava Corp permanently."''