* AbilityOverAppearance: Cameron Frye was originally envisioned as being chunky and "homely in a lovable way". Creator/JohnHughes then remembered the tall, thin, very attractive (29-year-old!) Alan Ruck from auditions for ''Film/TheBreakfastClub'' (he didn't make the cut that time), and cast him based on that performance. What followed was what is considered to be one of the most soulful, enduring portrayals in Hughes' oeuvre. It probably also helped, however, that Ruck and Creator/MatthewBroderick had previously co-starred together in ''Film/BiloxiBlues'', and as a result of this, according to Ruck, "We didn't have to invent an instant friendship like you often have to do in a movie. We ''were'' friends."
* ActorAllusion: Ferris hacks into the school's system from his computer to change the number of absences he's had. [[Film/WarGames That's not the first time Broderick hacked into his school's system.]] Though Bueller is less enthusiastic about it:
-->''"I asked for a car, I got a computer. How's that for being born under a bad sign?"''
* BeamMeUpScotty: Ben Stein as the economics professor never says, "Anyone? Anyone? Bueller? Bueller?" He does say these lines but separately. He first says, "Bueller? Bueller?" while taking attendance and then later during his lecture asks, "Anyone? Anyone?"
* CaliforniaDoubling: Ferris' house is actually in Long Beach, California and the restaurant they go to is in West Hollywood.
* CastIncest: On-screen siblings Creator/MatthewBroderick and Jennifer Grey dated and were even engaged for a while after appearing in this film together.
* CreatorBacklash: Creator/JohnHughes actually disliked the TV adaptation and actually tried to block its release. Unfortunately, however, he was unable to do so, and the best that he could do was to stipulate that Creator/{{NBC}} and Creator/{{Paramount}} not use his name to promote the series.
* DawsonCasting: Averted with Mia Sara, (Sloane) who was 18 (playing a high school junior). Played straight with Matthew Broderick (Ferris) who was 23, Jennifer Grey (Jeannie) who was 25, and Alan Ruck (Cameron) who was ''29'' when the film was shot during the fall of 1985.
* DeletedScene:
** Ferris asks his dad on the phone about bonds his father purchased when he was born, he then takes one of them from a shoebox in his father's closet, cashes it at the bank with his girlfriend (telling the hard-of-hearing teller they are pregnant with a jeep), and uses the money to pay for his day off. It was removed because it made Ferris look like a thief rather than a lovable rogue
** At one point in the film there was a scene in which Ferris, Cameron, and Sloane would visit a Chicago radio station and Ferris would talk about how "come next year, I'll be the first kid to ride on the Space Shuttle". It was even featured in the film's trailer. Unfortunately, however, less than five months before the film was to be released, the [[UsefulNotes/{{NASA}} Challenger]] exploded 73 seconds after launch, resulting in the deaths of all seven aboard, including New Hampshire school teacher Christa [=McAuliffe=]. Because of this, Creator/JohnHughes had the trailer recalled from theaters and the line was edited out of the final film.
** Ferris orders something in French on the menu, and after everyone at the table tastes it, he is informed by the snooty waiter that he ordered "sweetbreads", which is a French dish made from the thymus gland. It was removed because it showed the waiter getting the better of Ferris, but later in the movie when Ferris is recounting the day to Cameron, he remarks "we ate pancreas".
* DyeingForYourArt: Creator/CharlieSheen stayed awake for 48 hours before filming his scene so that he would appear tired and strung-out. Now he prefers the quicker method of good, all-natural cocaine.
* EnforcedMethodActing: In the cab, when Ferris tickles Sloan. Actress Mia Sara's laughter was real, because Creator/MatthewBroderick and Alan Ruck actually took off her shoe and tickled her foot.
* FlipFlopOfGod: The DVD commentary pegs Ferris as a spoiled jerk. However, Hughes intentionally cut a scene that ''explicitly'' makes Ferris a thief, and cast Creator/MatthewBroderick in the role because he felt Broderick was the only one who could make Ferris likable. So do we empathize with Ferris or not? Either interpretation of the character is equally valid. And it doesn't help that both interpretations ''can'' work concurrently with each other (i.e. Ferris is a jerk and trickster, but he's OUR jerk and trickster).
* FollowTheLeader: After this movie became hugely successful, many teen shows throughout the next decade or so (particularly those aimed at children) implemented a Ferris Bueller-like character (i.e. Zack Morris from ''Series/SavedByTheBell'', Ronnie Pinsky from ''Series/SaluteYourShorts'', Parker Lewis from ''Series/ParkerLewisCantLose'', etc.). Some of these were just shallow/one-dimensional caricatures of Ferris; others weren't.
* HarpoDoesSomethingFunny: Ben Stein originally only had his iconic "Bueller......Bueller" scene, but Creator/JohnHughes thought he had such distinctive voice that he asked Stein to just talk about any subject he knew a lot about, which led to the short scene of him teaching a class on the Great Depression.
* IAmNotSpock: For a long time, Creator/MatthewBroderick never liked talking about this movie, though it seems he's eased up about it, [[AdamWesting since he appeared in a 2012 Super Bowl commercial that parodied the film]].
* IWantYouToMeetAnOldFriendOfMine: Creator/MatthewBroderick and Alan Ruck had previously co-starred together in ''Film/BiloxiBlues'', while Creator/CharlieSheen and Jennifer Grey previously co-starred together in ''Film/RedDawn1984''.
* OldShame: Creator/CharlieSheen said a few years later that watching his one scene in the movie made him want to punch himself in the mouth. He seems to have made peace with it, reprising his character in his exact scene from the John Hughes tribute episode of ''Series/TheGoldbergs'' in 2015.
* OrphanedReference: When telling Cameron about how great the day was, Ferris says, "We ate pancreas". The restaurant scene originally had Ferris order sweetbreads, only to later be told that it's in fact pancreas. As mentioned above, it was deleted because it portrayed Ferris as a complete ButtMonkey as opposed to the LoveableRogue John Hughes wanted to portray him as.
* PlayingAgainstType: Most of Creator/MatthewBroderick's roles, before and after this film, are more milquetoast than Ferris.
* RecycledSet: The hall scenes in which Jeanie is seen walking down the hall and the kid collecting money to save Ferris are the halls from ''Film/TheBreakfastClub''.
* RecycledTheSeries: Lasted barely a season, mainly because it was heavily changed to the point where it could be considered InNameOnly. Among other things, the setting was changed from Chicago to L.A., Ferris was now an obnoxious nerd who [[SmallNameBigEgo only believed he was wildly popular]] (and attended school without complaint!), Cameron was still neurotic but lacked the tragic {{backstory}} from the film, thus making him a figure of fun, Sloane was now catty and shallow (the spelling of her name was also changed to ''Sloan''), [[ArsonMurderAndJaywalking Ferris's parents were now named Bill and Barbara instead of Tom and Katie]], and the list goes on and on. Not even a very young Creator/JenniferAniston (as Jeannie) could save it.
* RomanceOnTheSet: The actors who played Ferris's parents (Cindy Pickett and Lyman Ward) later got married in real life. Unfortunately, however, they divorced in 1992.
* ShoutOut: Sloane got her name from Sloane Tanen, daughter of then Paramount Film Group president Ned Tanen.
* StarMakingRole: Three years prior, ''Film/WarGames'' is what got Broderick noticed. But this movie clearly is what made Broderick a star, and it is arguably his most famous role.
* TechnologyMarchesOn:
** If mobile phones were as widespread then as they are today, it'd be harder for Ferris to bluff his parents if he could be contacted anytime, anywhere.
** A video of Ferris dancing on the parade float or him catching the foul ball at Wrigley Field would have most likely made its way to Website/{{Youtube}} today, and the jig would be up.
** Ferris' line, "I asked for a car. I got a computer. How's that for being born under a bad sign?" doesn't work the same as it did. While a modern teen expecting a car would still be disappointed to only get a computer, computers are now much more desirable for teens than they were in the 1980s, and virtually every teen would expect to get their own eventually.
* TooSoon: As mentioned above, John Hughes originally shot a scene in which Ferris would discuss on a radio show wanting to be the first kid to ride the Space Shuttle, but ended up excising that scene due to the Challenger accident.
* ThrowItIn:
** "They think he's a righteous dude" was improvised by Edie [=McClurg=], the actress who played Grace.
** Ben Stein improvised the entire lecture about the Hawley-Smoot Tariff.
** Rooney's line about leaving "my cheese in the wind" was ad-libbed. Creator/JohnHughes wanted a comment that was complete nonsense.
* UnintentionalPeriodPiece: Ferris' leopard pattern vest he wears throughout the film places it firmly in the eighties. EightiesHair and suspenders add to it.
* WhatCouldHaveBeen:
** Creator/JohnHughes' first choice to play Ferris was Creator/MichaelJFox. Amusingly, Broderick was the first choice to play Fox's role of Alex P. Keaton on ''Series/FamilyTies''. However, Broderick declined, partially because his father, James Broderick, had become terminally ill, and partially because he did not actually want to commit to a weekly TV series.
** Creator/JohnnyDepp was also considered, as well as Creator/RobertDowneyJr, Creator/JimCarrey, Creator/RobLowe, Creator/TomCruise and Creator/JohnCusack.
** Mia Sara almost didn't play Sloane because at the same time she auditioned, she was simultaneously auditioning to play Sarah in ''Film/{{Labyrinth}}''.
** Molly Ringwald missed out on Sloane. According to Ringwald, "John wouldn't let me do it: he said that the part wasn't big enough for me".
** Anthony Michael Hall turned down the role of Cameron, as he didn't want to get typecast. Creator/EmilioEstevez also turned it down. For some reason, Creator/JohnCandy auditioned.
** Paul Gleason was considered for Ed Rooney. Gleason had previously played the role of an assistant principal in ''Film/TheBreakfastClub''.
** The script contained a scene where Ferris, Sloane, and Cameron go to a strip club. Paramount executives told Creator/JohnHughes there were only so many shooting days left, so the scene was scrapped.
** Choreographer Kenny Ortega[[note]]who would later choreograph co-star Jennifer Grey's next film, ''Film/DirtyDancing''.[[/note]] had originally choreographed an elaborate dance sequence for when Matthew Broderick sang atop the float at the parade. Unfortunately, however, Broderick had dislocated his knee a few weeks earlier filming the scene at the end of the movie where hes running through yards on his way home, so the choreography had to be scrapped.
** After working together on Film/WeirdScience, Creator/JohnHughes offered Creator/BillPaxton the role of the garage attendant. However, Paxton turned it down because he felt the role was too small. He admits that he regrets turning it down because Hughes never offered him a role again.
** The movie didn't have a soundtrack album for decades because Hughes himself blocked one back in the 1980s, because he felt the movie's music was too eclectic to make a coherent album. Many were delighted when La-La Land Records released an official album (there have been ''bootleg'' releases) in 2016.
* WordOfDante: A researcher discovered the titular day off was [[http://sports.yahoo.com/mlb/blog/big_league_stew/post/Bueller-For-which-Cubs-game-did-Ferris-play-hoo?urn=mlb-318065 June 5, 1985]], based on the Cubs game that Ferris goes to in the movie. If true, that would add extra relevance to Ferris' thoughts about life after high school, as the gang would be mere days away from graduating. The game where scenes from the film were shot was actually played on September 24.
* WordOfGod: Creator/JohnHughes said in 1999 that several of his "Shermer" movies, including ''Film/SixteenCandles'', ''Film/TheBreakfastClub'', ''Ferris Bueller's Day Off'', and ''Film/PlanesTrainsAndAutomobiles'', are all a part of the [[TheVerse same universe]]. According to Hughes, [[Film/SixteenCandles Samantha Baker]] knows Ferris.
* WordOfSaintPaul: [[http://www.independent.co.uk/arts-entertainment/films/news/why-cameron-wore-a-red-wings-jersey-for-almost-the-entirety-of-ferris-bueller-s-day-off-a7087126.html According to Alan Ruck]], the reason Cameron wears a Gordie Howe Detroit Red Wings jersey is because Cameron had a grandfather in Detroit, whom he had a great relationship with, that used to take him to Red Wings games.
* WriteWhoYouKnow:
** Cameron and Charlie Sheen's character were both based on people Creator/JohnHughes knew in high school.
** In addition, Alan Ruck based Cameron's phony impression of Sloane's father on legendary stage director Gene Saks, who had previously directed both him and Creator/MatthewBroderick in ''Film/BiloxiBlues''.

Other Trivia:
* This is former U.S. Vice President UsefulNotes/DanQuayle's favorite movie.
* Three replica [[CoolCar 1961 Ferrari 250 GT Spyder California]] replicas were used in filming.
** The Hero car was built by Mark Goyette and leased to Paramount for filming. This one was used in almost all exterior shots, and is the one that jumps over the camera. When filming was completed, it was returned to Mark, with the exhaust crushed and the rear body panels cracked. He repaired it and sold it to a young couple in California. The husband ran it off the road, and Mark rebuilt the front end. The couple later sold it in the '90s, and it resurfaced in the early 2000s, but hasn't emerged again since.
** A kit was sold to Paramount for their stunt car, but they did such a poor job assembling it that it was unusable for anything but falling out the window of Cameron's house at the end. It was later rebuilt and ended up in Planet Hollywood Minneapolis, but fell off the map along with Planet Hollywood Minneapolis.
** A third kit, meant to be a shell to be dropped out of the window, was bought but never completed. Mark Goyette mentions he heard it was completed and sold off, but it could just as likely be sitting in a backlot at Paramount.
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