!!The movie:
* ActingForTwo: In the flashback, the medieval Slayer and her Watcher are played by the same actors as Buffy and Merrick. On the other hand, the Slayer and the Watcher continually reincarnate looking identical to her past lives, so they are theoretically still the same characters.
* CastingGag: The BigBad of the movie was a vampire played by Creator/RutgerHauer. Creator/AnneRice had originally envisioned Hauer as Lestat when she wrote ''Literature/TheVampireChronicles'', but by the time ''Film/InterviewWithAVampire'' was filmed in the early 90s, she said he was too old to play Lestat.
* CreatorBacklash: Joss Whedon eventually walked off the set due to how his vision was being mishandled and rewritten.
* DawsonCasting: 22-year-old Creator/KristySwanson playing high school senior Buffy.
* DeletedRole: Creator/SethGreen filmed some scenes as a vampire but most of them were cut. He can be seen from behind and briefly when Buffy kicks him outside the gym.
* FakeNationality: The medieval maiden played by the California-born Swanson in the flashback sequences would obviously have to be non-American. She comes off as [[FakeBrit English]] [[NotEvenBotheringWithTheAccent (not that Swanson tries very hard)]], but a brief line by Merrick suggests that she was Hungarian. (In the original script, she's an Italian.)
* FakeBrit: Merrick, a British character being played by the Canadian Creator/DonaldSutherland.
* ThrowItIn: Amilyn's ludicrously protracted and over-the-top death in the movie, ad-libbed by Creator/PaulReubens.
* ThePeteBest: Kristy Swanson was the original Buffy, but of course Sarah Michelle Gellar is the one who played the role in the TV series. And achieved greater fame as a result.
* WagTheDirector: According to Creator/JossWhedon, Creator/DonaldSutherland was under the impression that he was the star of the film. And rewrote all of his dialogue.
* WhatCouldHaveBeen:
** Creator/AlyssaMilano almost got the lead role in the original movie. She would later become one of the leads for ''{{Series/Charmed}}'' - a show heavily influenced by ''Buffy''.
** The first incarnation of Creator/JossWhedon's idea of "a young woman who is far more than she seems" that eventually developed into ''Buffy'' was called "Rhonda the Immortal Waitress".
** Music/DavidBowie, Music/MickJagger and Creator/CaryElwes were set to make cameos as vampires but these were cut due to time and budgetary constraints.
** Amilyn was written to be female and played by Joan Chen. When she dropped out, the character became male instead.
** In the original version of the script, Merrick committed suicide to escape being turned into a vampire by Lothos, who wanted to know the Slayer's identity so he could dispatch with her. It is this version that was restored in the Buffy "Origin" comic.
** Buffy says she wants to marry Creator/ChristianSlater. In the original script, she said Creator/CharlieSheen.


!!The TV series:
* AbilityOverAppearance:
** Producers were reluctant to cast Creator/AmberBenson as Tara because she was too voluptuous - they wanted someone daintier and waifier to take Willow's place as TheWoobie. But Amber won them over with her ability to play awkward and vulnerable.
** Creator/AlysonHannigan's casting went something like this too. Joss stated that all the other girls who auditioned for Willow wore NerdGlasses and acted stereotypically [[HollywoodNerd nerdy]] (including Riff Regan, who played her in the pilot). Alyson won the part based on the fact that she didn't do that.
* ActingInTheDark: Clare Kramer and Charlie Weber didn't know about the link between Glory and Ben until the episode it was revealed.
* ActorAllusion:
** Giles piping in "Dance Macabre" during his slideshow presentation in "[[{{Recap/BuffyTheVampireSlayerS4E10Hush}} Hush]]". Creator/AnthonyStewartHead appeared in the pilot of ''Series/JonathanCreek'', which used this song as its theme.
** Mark Metcalf had previously played "The Maestro," Italian for The Master, on ''Series/{{Seinfeld}}''.
** Seth Green played Alyson Hannigan's boyfriend in ''Film/MyStepmotherIsAnAlien''.
* ActorInspiredElement: Alyson Hannigan was the one who introduced Joss Whedon to Nerf Herder's music, leading to them scoring the show's theme song.
* ActorSharedBackground:
** Creator/JamesMarsters based his accent on Anthony Stewart Head's. Giles uses an RP English accent on-camera, but his actor sounds like a working-class "tough guy" in real life, using an accent close to Estuary English. Head uses it for Giles' adolescent persona in "Band Candy."
** In "Nightmares", Buffy's personal nightmare is being buried alive by the Master. Creator/SarahMichelleGellar is terrified of graveyards for this same reason, which is [[NightmareFuel amusing]] seeing as her character was buried alive ''twice'' in the show ("Nightmares" and "Bargaining Pt. 1"), and [[IronicFear spends most of her evenings in graveyards]].
** Creator/AlysonHannigan maintains that she [[PerformanceAnxiety cannot sing or dance]] (which hasn't stopped multiple writers from shoehorning her into [[Series/HowIMetYourMother splashy musical numbers]], but oh well), mirroring Willow's nightmare of being forced to sing ''MadameButterfly''. ("[[{{Recap/BuffyTheVampireSlayerS1E10Nightmares}} Nightmares]]")
** Baby Buffy went through a phase during which she idolized ice skater Dorothy Hamill. Sarah Michelle Gellar Gellar enjoys figure skating in real life.
** The scene in "[[Recap/BuffyTheVampireSlayerS3E8LoversWalk Lovers Walk]]" where Cordelia gets impaled is based on a real incident. At five years old, playing around a swimming pool that was still under construction, Creator/CharismaCarpenter fell onto a piece of rebar. Only in real life she fell off a horse and not through stairs.
** Faith became a Boston native after Creator/ElizaDushku was cast, though Eliza herself is actually from Watertown rather than South Boston like Faith.
* BreakthroughHit: For Creator/JossWhedon.
* TheCastShowOff:
** In "What's My Line" Buffy goes ice skating, showing off Sarah Michelle Gellar's talent at it.
** Anthony Stewart Head is called on to sing in "Where The Wild Things Are" and "Restless", before the MusicalEpisode.
** Michelle Trachtenberg did ballet for years, and showed off her dance talents in "Once More With Feeling".
* CreatorBacklash:
** Creator/SarahMichelleGellar disliked Season 6 because of the dark tone of the storylines. She also wasn't a fan of the extensive preparation that had to be done for the MusicalEpisode.
** Most of the cast came to hate the library scenes because they would take forever to film.
** Subverted with Alyson Hannigan. She requested that she not sing too much in "Once More With Feeling" because she hates her singing voice. But upon seeing the episode, she was surprised at how good she sounded and regretted not singing more.
** Creator/JamesMarsters was so disturbed by Spike's attempted rape of Buffy that he had it written into his contract that he would never film such scenes again.
** Creator/SethGreen disliked being OutOfFocus in Season 3, as he hated having to show up for work when he'd only have one or two lines the whole time. This is why Oz gets PutOnABus midway through Season 4.
** Jenny Calender's actress, Robia Lamorte, had become a born-again Christian by the time she reprised her role as a guise for The First Evil and didn't take kindly to it, seeing it akin to playing Satan.
* CreatorsFavorite: Xander (who was a stand in for Joss), Dawn (with her actress being such a big fan of the series, focus was given to her), and Kennedy (Whedon really liked the character and gave a lot of focus to her) being standouts.
* TheDanza: Larry Bagby III as Larry Blaisdell. DB Woodside as Robin Wood.
* DawsonCasting:
** Some actors were a full decade older than their characters. In an extreme example, Creator/CharismaCarpenter was 26 when she played 16-year-old Cordelia.
** Averted by Dawn and Faith, who are both the same age as the actresses playing them, Creator/ElizaDushku was even legally emancipated from her parents so she wouldn't be limited by child labour laws. Dawn was likewise made a couple of years older to match Michelle's age, since she was originally written as a preteen. Mercedes [=McNabb=] (Harmony) was also sixteen when the first season was shot.
* DyeingForYourArt: According to Joss Whedon, all three lead actresses had the same brownish auburn hair colour when they were cast. Sarah Michelle Gellar eventually bleached her hair blonde for Season 2, Alyson Hannigan went fully redhead, and Charisma Carpenter darkened hers.
* FakeBrit:
** Spike, played by American Creator/JamesMarsters. He based his accent off Anthony Head's real voice.
** Juliet Landau as Drusilla, attempting the Victorian era cockney accent.
** Wesley, played by Seattle native Alexis Denisof.
** Potentials Molly and Annabelle are played by Americans Clara Bryant and Courtnee Draper.
** The men from the Watchers' Council are played mostly by Americans, with the exception of Alistair Duncan.
** Kali Rocha as Cecily in "Fool For Love". If the theory that Cecily and Halfrek are the same person is canon, then this is an in-universe example.
* FakeIrish: David Boreanaz attempts an Irish accent for Angel's past. Emphasis on [[OohMeAccentsSlipping attempt]].
* FakeNationality: Bianca Lawson is American playing Kendra, who WordOfGod confirms is from rural Jamaica.
* HeAlsoDid: Nicholas Brendon (the guy who played Xander) [[http://verybadkoalas.com/2010/09/29/episode-1/ has a webcomic]].
* HeyItsThatPlace:
** The external (and some internal) shots of Sunnydale High School are of Torrance High, the same school used for the ''Series/BeverlyHills90210''
** The exterior of Angel's mansion is of Frank Lloyd Wright's Ennis House, a popular shooting location.
** Buffy's old school, Hemery High, is the clock tower made famous in ''Film/BackToTheFuture''.
** "Fear Itself" took place in what would become better known as the Murder House house in ''Series/AmericanHorrorStoryMurderHouse''.
** The battle between the Slayers and Kakistos ("Faith, Hope, and Trick") takes place inside L.A. Firestation 23, also used as HQ for the ''Franchise/{{Ghostbusters}}.''
** The Gentlemen are seen floating down the same street that later served as [[DesperateHousewives Wisteria Lane.]]
* KilledByRequest: [[spoiler: Anya]] became the only regular character permanently killed off in the GrandFinale, because [[spoiler: Emma Caulfield]] had no interest in playing the character again and asked for it.
* NamesTheSame:
** Everyone knows Cordelia. Cheerleader. AlphaBitch. Rival of Buffy. Hopeless with rifles. There's also [[VideoGame/LollipopChainsaw Cordelia.]] Her little sister is a cheerleader. {{Tomboy}}. Very much an ally. Wields a sniper rifle.
** Definitely a coincidence, but still funny: in the comic ComicBook/{{WITCH}}, there's a redheaded MagicalGirlWarrior called ''Will'' who has a bit of LesYay with a shy MagicalGirlWarrior called Tara''nee''. The same comic also features a LovableAlphaBitch called Cor''n''elia.
* NamesToRunAwayFromReallyFast: Real life example: Robia [=LaMorte=]'s (miss Calendar) surname means "(the) death" in Italian and "the dead woman" in French.
* TheOtherDarrin:
** Kristy Swanson played Buffy in the movie, but Sarah Michelle Gellar took over for the TV show because Kristy was thought too old to play a sixteen-year-old at the age of twenty-eight. Likewise Donald Sutherland played Merrick in the movie, and is portrayed by Richard Riehle in a flashback to Buffy discovering she's a Slayer.
** Nikki Wood, the second slayer Spike kills, is played by a stuntwoman in "Fool For Love." When The First assumes her shape in Season 7, she was recast as a more vulnerable-looking actress.
* TheOtherMarty:
** Riff Regan played Willow in the unaired Proof of Concept to sell the show but never intended to play her in the series.
** Another actress was cast as Anya, but dropped out when she found out it was only for two guest spots. Emma Caulfield took over and eventually became a regular for the rest of the series.
* PlayingAgainstType:
** So Creator/SethGreen isn't the PluckyComicRelief?
** Creator/NathanFillion as the sadistic, satanic serial killer working for the Big Bad (If you take the First Evil to be Satan and that Caleb had killed people ForTheEvulz before meeting it).
* PlayingGertrude: Charisma Carpenter is older than Robia La Morte, who plays her teacher.
* ProductionPosse: Several actors who had starred in ''{{Series/Firefly}}'' had smaller parts on both this and ''Angel''. Notably Nathan Fillion as Caleb. Jonathan M Woodward played Holden in "Conversations With Dead People" and Tracy in ''Firefly'''s "Message In A Bottle" (as well as Knox on ''Angel'').
* PromotedFangirl:
** Michelle Trachtenberg was a huge fan of ''Buffy'' before being signed onto the show, and once told Joss "There was never a Buffy episode that sucked. I love you!"
** When "[[Recap/BuffyTheVampireSlayerS3E8LoversWalk Lover's Walk]] episode originally aired in the US, it was followed by an advert for the phone service 1800-COLLECT, in which Creator/SarahMichelleGellar and Creator/DavidBoreanaz offered a prize of a walk-on part in "[[Recap/BuffyTheVampireSlayerS3E20TheProm The Prom]]."
* RealLifeRelative: Nicholas Brendon's twin brother worked as his stunt double, and they also brought him in to play Xander's magically created double in season five's "[[{{Recap/BuffyTheVampireSlayerS5E3TheReplacement}} The Replacement]]".
* RealLifeWritesThePlot:
** Kristine Sutherland announced she wanted to leave the series at the end of Season 3. Joss Whedon compromised and featured her in only five Season 4 episodes. She agreed to come back for Season 5 [[spoiler: to be killed off]].
** Halfrek was meant to appear in more Season 7 episodes, but Kali Rocha was committed to a play. In fact she filmed all her Season 7 scenes in one day.
* RecycledTheSeries: Although not so much recycled as "remade properly" according to Creator/JossWhedon's vision.
* RomanceOnTheSet:
** Here's an odd one: Amber Benson and Adam Busch... who played Tara and Warren respectively.
** Creator/AlysonHannigan (Willow) is married to Alexis Denisof (Wesley).
* ShrugOfGod: Joss Whedon was originally shocked at people shipping Buffy and Faith. But when one fan had him look at her website, where she analysed all the LesYay scenes between them, he later said the fans were spot on about the subtext between the Slayers.
* ThrowItIn:
** The famous Creator/MutantEnemy title card was reportedly scribbled by Whedon with only seconds to go until broadcast.
** In "[[Recap/BuffyTheVampireSlayerS2E14Innocence Innocence]]", The scene where Angel dumps Buffy in his apartment was originally supposed to take place on Buffy's lawn. Halfway through shooting the scene, SMG and David Boreanaz told Joss that the scene wasn't working, so he moved it to the bedroom. Buffy can still heard saying she saw him "at the house". She was so LostInCharacter afterwards they had to close down the set for half an hour, being that invested in the romance.
** The gag in "[[Recap/BuffyTheVampireSlayerS3E18Earshot Earshot]]" with Giles walking into a tree was ad-libbed by Creator/AnthonyStewartHead. He never dreamed Joss would keep in the cut.
** In the [[Recap/BuffyTheVampireSlayerS3E22GraduationDayPart2 Season Three finale]], Cordelia [[SecurityCling cowers behind]] the diminutive Jonathan. According to Danny Strong, this scene was an idea of Charisma's, because she was leaving for ''Angel'' and never got much screen time with him.
** Not in the original work but in the motion comic ''Anywhere But Here'' there is a scene where Kennedy guesses Willow is upset about Tara's death. A line's added that makes her look like Queen Bitch.
** The scene in the pilot where the Master blinds a vampire and says "you've got something in your eye" was added to fill time.
** Kali Rocha was cast as Halfrek in Season 6 after having briefly played Spike's human love interest Cecily in a flashback. Knowing that eagle-eyed viewers would notice, they wrote in Halfrek saying "William?" when she sees Spike.
* TooSoon: The episode "Earshot", which depicts a student bringing a rifle to school [[spoiler: (albeit to kill himself and no one else)]], was set to air within a week of Columbine and was therefore delayed until after the season finale, which was also delayed in light of Columbine because of [[spoiler: the destruction of Sunnydale High School.]]
* TrollingCreator: David Fury wrote in many scenes of Buffy laughing just to troll Sarah Michelle Gellar, who hates laughing on camera.
* TropeNamer: For...
** BigBad: And, by extension, its {{snowclones}}:
*** BigBadDuumvirate: The Trio.
*** BigBadEnsemble
*** BigBadWannabe: Poor Spike fits the bill. And he's the trope namer for "Big Bad", too! Life is so unfair.
*** BigGood: This being a Whedon show, though, even the Big Goods (Quentin Travers, Sineya, the Shadow Men) [[KnightTemplar aren't very good]].
** BreakawayPopHit[[invoked]]: "Once More With Feeling"
** BuffySpeak
** ButtMonkey: Xander used it to refer to himself in "Buffy vs. Dracula."
** CameBackWrong: "Smashed"
** CameBackStrong: "Prophecy Girl"
** FunnyAneurysmMoment: "The Freshman" (InUniverse version)[[invoked]]
** GameFace: "Prophecy Girl"
** InferioritySuperiorityComplex: Holden Webster's expert opinion on Buffy. ("Conversations with Dead People")
** InsaneTrollLogic: "Triangle"
** UseYourHead: Spike's [[BadBoss helpful suggestion]] to one of his mooks ("[[Recap/BuffyTheVampireSlayerS2E3SchoolHard School Hard]]")
* And the ''[[Administrivia/RenamedTropes former]]'' Trope Namer for:
** BadassDecay: Formerly known as Spikeification.[[invoked]]
** ChekhovsBoomerang: Formerly known as Olaf's Hammer.
** FangThpeak: Formerly known as WhedonThyndrome.
** WeirdnessCensor: Formerly known as SunnydaleSyndrome.
* {{Tuckerization}}: Riley's last name Finn was taken from Marti Noxon's dog.
* WhatCouldHaveBeen:
** The entire first season was shot before the pilot had even aired, so some of the scenes were re-shot. Buffy's "it's my first day" speech to Giles was actually the ''last'' scene filmed, as they decided that Sarah Michelle Gellar's originally performance was too aggressive.
** At the height of its popularity, a animated version was considered. They had got the designs down and even made a promo. But no network was willing to buy it and it wound up dropped in the end. Though it did get a nod in the season 8 comic which somewhat lampshades the missed opportunity.
** Ms Calendar was originally written as 'Nikki' instead, but they changed it to Jenny to avoid confusion with Nicholas Brendon (who was called Nicky by everyone on set). This was apparently no longer an issue by the time they wrote in the character of Nikki Wood.
** Creator/JossWhedon planned to make a spin-off called "Ripper", about Giles' adventures in England. At first it was meant to be a show, then a mini-series, then finally a made-for-TV movie. Apparently, he still hopes to make it.
** After the series ended, Creator/ElizaDushku was offered her own spin-off series as the character Faith. But then she turned it down to do ''Series/TruCalling''.
** Amongst those who auditioned for Buffy were Creator/KatieHolmes and Creator/SelmaBlair.
** Creator/RyanReynolds was originally offered the role of Xander. He passed on it because of his own awful high school experiences. "I love that show and I loved Creator/JossWhedon," Reynolds told 'The Toronto Star' in 2008. "But my biggest concern was that I didn't want to play a guy in high school."
** Creator/NathanFillon auditioned for Angel. He played Caleb in the last season.
** Tucker from Season 3's "The Prom" was set to be a member of the Trio, but his actor wasn't available. So they created Andrew as Tucker's brother, with a RunningGag that [[RememberTheNewGuy no one remembers him]].
** Dawn was originally intended to have the power to speak to the dead. She was also supposed to be able to move objects with her mind. These powers were later dropped.
** Originally, Whedon didn't want either of Buffy's parents to appear as characters on the show. Accepting that that could get complicated, he settled on just having her mother, Joyce, appear in a nearly regular role, while Buffy's father Hank appeared in very few episodes.
** Oz was originally supposed to wear thick rimmed glasses, much like the lead singer of Music/{{Weezer}}. This was dropped at the last minute as Whedon felt that it looked tacky.
** Whedon toyed with the idea of making Xander gay instead of Willow. But when he saw the chemistry between Amber Benson and Alyson Hannigan, he made them a couple.
** Spike, Oz, Faith, Wesley and Drusilla were all supposed to be killed off, but have ended up living long past their initial storylines. Also, [[spoiler:Jenny and Joyce were supposed to be killed off sooner than they were]].
** The Oz-Veruca storyline in season four was supposed to last longer, but had to be cut short. Seth Green had been cast in a film whose production was suddenly pushed forward, requiring him to be written out sooner.
** According to Nicholas Brendon, he and Creator/SarahMichelleGellar proposed a storyline for season seven where Xander and Buffy get together romantically. Their idea was shot down, and they continued with the Buffy-Spike relationship.
** The Master was originally supposed to have a beard and long hair before Mark Metcalf suggested the bald look as a homage to ''Film/{{Nosferatu}}''.
** Creator/JamesMarsters originally auditioned for Spike with a Texan accent. This was quickly jettisoned in favor of a London accent instead.
** Xander was supposed to be revealed as Glory's host, tying in to his declaring at the start of the season that he's "through being everyone's butt monkey" and ultimately expelling her himself.
** Throughout Season 7, Joss had terrible trouble deciding if Principal Wood would survive the finale. He describes the result as the episode just happening to be filmed on a day where he was leaning toward Wood surviving.
* YouLookFamiliar:
** Spice Williams plays the police instructor who tries to murder Buffy, Patrice, in "What's My Line?" She also appeared in "The Zeppo" as a member of the Sisterhood of Jhe, and later turned up on ''Angel'' as a convict hired to kill Faith in prison.
** Creator/JeffKober first appeared in season three episode "Helpless" as a vampire named Kralik. He appeared again during season six as warlock Rack.
** Brian Thompson portrays the vampire "Luke" in season 1, as well as the demon called "The Judge" in season 2.
** Tom Lenk plays a vampire lackey to Harmony a few season before playing Tucker's brother (and a member of the Trio).

!!The comics:
* ScheduleSlip: the last ''Spike'' issue.
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