Michael J. Fox plays Marty, his older self in 2015, his children Marty Jr. and Marlene (yes, the daughter), and Seamus in 1885. He also posed as William for the picture of him in Part III, who he also later voiced in the Telltale game.
Thomas F. Wilson plays 1955 Biff Tannen, 1985 Biff (three versions, no less: the Jerkass from the beginning of Part I, the wimpy version from the end of parts I and III and beginning of Part II, and the Jerkass In Chief from the 1985-A universe in Part II), 2015 Biff and his grandson Griff, and Buford "Mad-Dog" Tannen in 1885.
Lea Thompson portrays both Lorraine Baines McFly, George's wife, in 1955, three versions of 1985, and 2015, and Maggie McFly, Seamus's wife.
Elisabeth Shue plays Jennifer's younger and older self at the same time in Part II.
Dawson Casting: Marty, Lorraine, George, Biff, Jennifer, etc. Makes some sense in Lorraine, George, and Biff's cases, since in the first movie they had to play both their teenage selves and their adult selves. Initially, not so much the case with Jennifer, who was played by 19-year old Claudia Wells in the first film, but then played by 26-year old Elisabeth Shue in the Sequels and that wig she wore to make her resemble Lea Thompson made her look every bit her age.
There are no back seats in a DeLorean, original or newly built; they only have a pair of front bucket seats. (That's why Jennifer had to ride sitting in Marty's lap.)
Nike sneakers with self adjusting laces can be yours... for $1,700.
Disowned Adaptation: Bob Gale hated many of the video game adaptations of the franchise, particularly the first one by LJN Toys. According to him, the makers of the game didn't want any input from the filmmakers, and when he saw it, he wanted a lot changed, but was told it was too late to do anything. He advised fans not to buy it, and felt that Telltale Games handled the process much better.
Basically, this is the whole reason why the sequels exist in the first place — but Sid Sheinberg had insisted on certain changes to be made in the first movie.
One of Sid Sheinberg's changes, from "Professor Brown" to "Doc Brown", has become integral in Back to the Future culture. (Just how much so is suggested by Michael J. Fox's repeated bloopers in filming The Frighteners: he called the Judge character "Doc".) He also insisted on Emmett Brown's chimpanzee pet being changednote his reasoning was that movies with chimps didn't make money; when Clint Eastwood's Every Which Way films were pointed out, he retorted "That was an orangutan.", which became the dog Einstein, and requested Marty's mother's name go from Meg to Lorraine (his wife's name). The last note is mentioned in the first film's trivia in regards to the title, to which the Bobs adamantly stuck to their guns.
Cost considerations forced a complete change in the tactic to return to 1985 in Part I, from powered by a nuclear test explosion to powered by the lightning bolt. By all accounts, it was a major improvement, as keeping it "local" in Hill Valley added an immediate urgency and gave Doc something to do with the clock tower (in the original script, he simply watched from a mountainside).
I Am Not Spock: Actor Thomas F. Wilson (Biff). He even wrote a song about it. He also started carrying small laminated cards he'd hand out to fans he'd run into, featuring answers to the most frequent questions he's asked about the movies. Not only is he exactly the opposite of a bully (and Biff) in real life, he drew on his real life high school experiences of BEING bullied in order to play Biff.
Fake American: Marty McFly — Michael J. Fox is in fact Canadian. You can hear his accent slip when he pronounces "sorry" as "sore-y."
Hey, It's That Place!: Courthouse Square, on the Universal Backlot, has been in dozens of productions. The set tragically burned to the ground in 2008. It has been rebuilt however.
There are three Joeys in the trilogy: Marty's uncle "Jailbird" Joey, one of Biff's goons (nicknamed "Skinhead"), and the barkeep's assistant in 1885.
The Other Darrin: Jeffrey Weissman replaced Crispin Glover as George McFly in the sequels. Likewise, Elisabeth Shue replaced Claudia Wells as Jennifer Parker.
Pop Culture Urban Legends: Once real-life history got into the decade of the 2010s, pretty much every year there would be a picture claiming that that day was the day Marty went to when he went to the future (with the date being photoshopped to the current date). It's easy to tell the fakes, since the real years in the movies all end in 5. Now that the real date has passed, only time will tell if these fakes will stop being made.
The Red Stapler: The DeLorean. At the time the movie came out the Delorean Motor Company had been bankrupt for almost 3 years and DeLoreans were considered a failed car. Nowadays there's an active "time machine conversion" community, DeLorean dealers, and DeLorean conventions — all because of Back to the Future. There's apparently even a company in Texas that bought the rights to the design and is making new DeLoreans.
Scully Box: Because Christopher Lloyd is 6'1", much taller than the 5'4" Michael J. Fox, camera tricks were used to avoid using one. For example, the two are rarely in the same shot together and, when they are, one is usually sitting down or much closer to the camera than the other. When Doc Brown is talking, he's often moving around so much that the viewer can't really tell how tall he is. Lloyd also improvised a hunch in his posture that helped give the character more of a Mad Scientist look.
The 1985 scenes, by being so current at the time of filming, falls headlong into this. Justified, in that the differences in eras wouldn't be nearly as significant if they'd been downplayed.
A specific one, that may not be understood by younger viewers, is the significance of the terrorists in BTTF I being Libyans. In 1985 when the movie came out, Libya under Col. Gaddafi was seen as a big Cold War bogeyman and considered by Ronald Reagan to be a serious enemy of the United States.
Banned in China: The film was banned in China mainland for a while because the notion of time travel "disrespects history". The ban has been lifted by now.
Big Name Fan: When the film was screened at the White House, Ronald Reagan personally asked the projectionist to rewind the film to Doc's disbelief about "the actor" who became president. Not only did he find the line hysterical, but he would use the line "Where we're going, we don't need roads" in his following state of the union address and was even offered a part in the third film.
The Cast Showoff: Kind of. Although Michael J. Fox is miming his performance of "Johnny B. Goode" he did actually learn to play the song (having played guitar in high school) so he could do so accurately. The guitar solo was actually played by Tim May, who also had previously performed the guitar solo on "Born to Hand Jive" from Grease.
Wonder why George had peanut brittle for dinner in 1985? Originally, after meeting with Biff, Marty tries to urge George to stand up for himself when a child selling peanut brittle shows up. Instead, he caves, buying all of it, with the child's father saying "See, I told you we'd only have to stop at one house."
Just when Marty leaves for the dance, Doc gets asked for a permit by a cop for his "weather experiment", and Doc gets it: a $50 bill, quite a bit of money back then. Also, Marty worries about his plan, asking "What if I go back to the future and I end up...gay?", to which Doc says "Why shouldn't you be happy?"
George, realizing he's late during the dance, goes into a phone booth to confirm the time, but Dixon, the bully who'd kicked George and later cuts in on him and Lorraine, traps him inside, with Strickland chastising him.
Two examples that didn't make the film because of Eric Stoltz. When they filmed the cafeteria scene, Stoltz roughed up Thomas F. Wilson for real and Wilson almost broke his collarbone. The normally nice guy Wilson planned to get revenge during the car park scene at the dance by actually punching Stoltz but Michael J. Fox had taken over by then so he never got the chance.
The outtake reel revealed that Marty did his Spit Take upon seeing Lorraine smoking because Michael J. Fox didn't know that the bottle he was drinking out of contained actual alcohol.
Executive Meddling: Attempted, but thwarted by the power of Spielberg. Universal head Sid Sheinberg didn't like the title Back To The Future and sent Spielberg a memo suggesting that it be changed to Spaceman From Pluto, in reference to the two scenes in which Marty is mistaken for an alien while in his hazmat suit, and asked that those two scenes be re-written to accommodate the title. Spielberg, who was good friends with Sheinberg and wanted to let him down gently, sent a letter back thanking him for "the wonderful joke," and Sheinberg was too embarrassed to admit he was serious.
Hostility on the Set: Tom Wilson has said that he and Crispin Glover didn't get along very well with Eric Stoltz when he was initially playing Marty, as Stoltz acted fairly arrogant throughout filming. Wilson even said that for years he thought Stoltz was fired due to his behavior on set, not because the producers wanted Fox originally.
Inspiration for the Work: Bob Gale conceived Back to the Future after he visited his parents in St. Louis, Missouri. Searching their basement, Gale found his father's high school yearbook and discovered he was president of his graduating class. Gale had not known the president of his own graduating class, and wondered whether he would have been friends with his father if they went to high school together.
Looping Lines: Crispin Glover lost his voice due to nervousness while filming. For some scenes, he had to silently mouth his lines, with his voice being dubbed in later at a recording studio.
Non-Singing Voice: Michael J. Fox did not sing "Johnny B. Goode" (the final singing audio was recorded by Mark Campbell), although he did learn to play it. For bonus points, his guitar coach Paul Hanson taught him to play the song in B, figuring an 80s guitarist like Marty wouldn't play a song in B flat. He's playing the song on-set in B and says it's a "blues riff in B," but nobody told Tim May, the guitarist who recorded the final audio, so the film audio is the original B flat version. Of course, May was more well versed in 50s music, having previously played the guitar solo on "Born to Hand Jive" from Grease.
Orphaned Reference: Ever wonder why George had peanut brittle for dinner in 1985? Originally, after meeting with Biff, Marty tries to urge George to stand up for himself when a child selling peanut brittle shows up. Instead, he caves, buying all of it, with the child's father saying "See, I told you we'd only have to stop at one house."
Sleeper Hit: No one expected the movie to become as big as it did. Robert Zemeckis openly admitted he was just hoping it would break even and the final bit with the Delorean flying and "something's got to be done about your kids!" was meant as a joke on Marty having just changed the past for his parents. Michael J. Fox recalled that when he was in London filming the Family Ties tv movie, his agent called and told him that the movie was a hit. He was pleased, but the agent had to reiterate that it was a BIG hit.
First, when Marty dines with his future maternal family in 1955, Lorraine asks whether his family owns a television set, to which Marty says, "Yeah, you know we have two of 'em...", making her younger brother say "Wow, you must be rich!", to which their mother says, "Oh, honey, he's just teasing you. Nobody owns two television sets!"
Later, Marty tries to explain his knowledge of an episode of The Honeymooners as having seen it as a rerun. In several non-English dubs of the movie, the word 'rerun' doesn't exist (usually because the country concerned had not adopted the policy of re-airing episodes of television shows as of the mid-eighties), so Marty says instead that he saw "The Man from Space" episode of The Honeymooners "on tape".
As the 1955 Doc looks at Marty's camcorder, he says "Now this is truly amazing: A portable television studio. No wonder your president is an actor, he's got to look good on television!"
Many of George McFly's mannerisms (the shaking hands, the infamous Honeymooner's laugh) were ad libbed by Crispin Glover. Allegedly, much of that was Glover's normal behavior, and the real challenge was getting him to act normal for the improved-1985 scenes.
Huey Lewis improvised the line "I'm afraid you're just too darn loud", as the silly excuse for Marty's band to be rejected.
During the "Mister Sandman" Sequence, when Marty sees the 1955 Texaco gas station, there was originally only one attendant working on a car, but Robert Zemeckis had the costume department find 3 more attendant costumes, believing it'd be funnier.
According to Bob Gale, Red (the homeless guy)'s name was ad-libbed by Michael J. Fox, so he isn't Red Thomas, the mayor of 1955 Hill Valley.
Troubled Production: Everyone involved in the first film was sure it would bomb because absolutely nothing went smoothly. (Among the crew, it was nicknamed The Film That Would Not Wrap.) The shoot nearly drove Zemeckis insane, ruined his health, and threatened to wreck his career if the film wasn't a hit. Star Michael J. Fox was running on fumes, commuting between the BttF and Family Ties sets with virtually no sleep in-between. In his interview on Inside the Actor's Studio, he notes that he was basically a zombie, which luckily enhanced his acting a fair bit.
J.J. Cohen was initially chosen to portray Biff Tannen after Eric Stoltz was cast as Marty McFly. However, Cohen was replaced from the role as he wasn't considered physically imposing enough next to Stoltz and was cast as one of Biff's gang members instead. According to Bob Gale, had Michael J. Fox been cast from the beginning, Cohen would've probably won the part, because he was much taller than Fox.
When Claudia Wells temporarily dropped out of the movie due to scheduling issues, Melora Hardin was briefly cast as Jennifer Parker opposite Eric Stoltz, but had to be replaced after he was dismissed as it was discovered that she was taller than Michael J. Fox.
Zemeckis and Gale originally pitched the film to Disney and then to Columbia Pictures, both of whom turned it down due to problems with the "kid dating his young mother" part of the story, albeit for completely opposite reasons: Disney felt that it was too raunchy, Columbia didn't think it was raunchy enough!note Keep in mind that this was at a time when the major studios were making raunchy sex comedies like Fast Times at Ridgemont High, Animal House, Cheech and Chong's Next Movie and other films which bordered on softcore porn. To them, this aspect of the story felt like a quaint form of Cringe Comedy.
The original time machine was a modified refrigerator, changed because it would have been a very stationary prop and Steven Spielberg had images of children locking themselves in the fridge to the horror of their parents. They also would have driven into the blast of a nuclear bomb to fuel the flux capacitor, changed because that alone would have doubled the production costs and the clock tower lightning strike made a fairly simple and stationary location. In the script written for this kind of time machine, the original timeline's Biff became a cop that kept "borrowing" stuff from George and had a daughter. With the change in the timeline, Biff became a security guard working for George, who became a boxing champion in that script.
For younger readers who don't understand how someone could become trapped in a refrigerator, they used to be held closed with a physical catch that could only be opened by a handle on the outside, and these older models were still somewhat plentiful at the time of the film. Modern ones all use magnets to hold themselves closed, with no catches.
The producers considered using "Papa Loves Mambo" by Perry Como when Marty arrives in the 1955 Hill Valley, before deciding on "Mister Sandman", thereby making it the "Mister Sandman" Sequence. "Papa Loves Mambo" would however show up in Part II where it's the song playing on the car radio as Biff drives to the dance..
There was originally going to be an explanation as to why Marty and Doc were friends: Doc just showed up one day and hired Marty to clean his garage, paying him $50 a week and free beer.
Originally when Marty looked Doc up in the past, Doc was going to be having a party, and was flanked by two women when he opened the door. The scene played out the same, but with Doc's two girlfriends laughing at Marty. Then, instead of getting the idea for time travel from falling down while hanging a clock, Doc was inspired after whispering something into a woman's ear and subsequently being hit in the head with a beer bottle.
In the original treatment, the time machine was rigged up inside a car wash. Marty McFly was chronically depressed, and in a hilarious misunderstanding, he mistook the time machine for a suicide device and climbed into it in order to kill himself. Also, there was originally going to be a major plot point where people in the past repeatedly mistook Marty for an alien.
The studio wanted Zemeckis to cut the "Johnny B. Goode" scene to improve pacing, but relented because the test audiences considered it one of the best parts of the movie.
Channel Hop: More than a decade after the original run on CBS, the show resurfaced from March to August 2003 on Fox on their then-new "Fox Box" Saturday morning lineup, programmed by 4Kids Entertainment- likely to fill the E/I quota.
Keep Circulating the Tapes: Only 18 episodes made it to VHS and Laserdisc, and none of them made it to DVD until October 20, 2015, when Universal released a Complete Series DVD set of the show—one day shy of the "futuristic" date Marty, Doc, and Jennifer visited in BTTF Part II. Up until then, you had the aforementioned incomplete releases, and whatever tapes were circulating from the original run on CBS, and the reruns on Fox (see above).
George's reluctance at letting Robert Zemeckis adapt A Match Made in Space into a movie references an article in USA Today's Real Life reproduction of the 2015 newspaper cover prop. According to this page, the phony article was written by Gannett vice president Matt Urbanos to replace the junk filler used by the original newspaper prop.
One popular fan theory was that Doc reverse engineered the hoverboard in order to get the time train working, since the board was pretty much the only bit of future tech at his disposal at the time. This idea was sort of used in "Continuum Conundrum," when Doc mentions he used components from the hoverboard to help get the steam trike time machine working.