The names of the goons from Biff and Griff's gangs, as well as Lorraine's friends.
As well as other info of the characters' backgrounds. Including Doc's mother's side of the family growing up in Hill Valley.
Almost Kiss: This happens three times in Part I, between Marty and Jennifer (though they did share a brief kiss before she went home with her dad). Towards the end of Part III, the two are finally able to kiss more definitively.
Aluminum Christmas Trees: The DeLorean. The DeLorean Motor Company went bankrupt in 1982, well before the film was made, and Robert Zemeckis had to argue with Universal to use the car since DMC wouldn't be able to give them any commercial endorsements. At the time the car was considered a failure; it's now entirely thanks to this series that anyone remembers it.
The use of the word "Dude" as an insult in the 1885 segments. Back then it was pretty much equivalent to "City slicker" or "Dandy", and meant someone from an urban environment trying to play cowboy. It's use as a term of affection only goes back as far as The Sixties.
Applied Phlebotinum: The flux capacitor makes time travel possible. Never mind figuring out how, it just does. Lampshaded by Marty.
"Nobody... calls me chicken." (With a variation in Part III, where he said "nobody calls me yellow.") This particular berserk button appears to be subject to sequel retconning, as it is nowhere in evidence in Part I.
The first time the DeLorean travels through time, it leaves its registration plate spinning on the spot behind it. After the DeLorean makes its final journey and gets destroyed by an oncoming train, the car's registration plate from 2015 is left doing the same thing.
In the original film's climax, Marty returns to the shopping mall just moments before his past self warps to 1955.
"The Power of Love" by Huey Lewis & The News is played in both the second scene of the first film, and the second-to-last scene in the final film.
In 2015, we find that Marty's life is not going too well, but the main plot then kicks in. We only return to the issue of Marty's future at the end of Part III.
In Part I Doc holds his experiment at the Twin Pines Mall, casually mentioning it used to be farmland, and that the owner tried to breed pine trees. When Marty travels back in time, he arrives at said farm, knocking over one of the "twin pines" while trying to escape the gun-wielding farmer. Upon returning to the present, the mall is now Lone Pine Mall.
The name of Clayton Ravine: Marty says that it's named after Clara Clayton, who fell to her death there — at least, she did until the Doc rescued her. When Marty returns to the future, the ravine is now named Eastwood Ravine, presumably to honor Marty (going by the name of "Clint Eastwood") who had faced down the robber and murderer Buford Tannen before (as far as they knew) dying in the ravine.
Several set pieces (such as a Tannen and his gang chasing Marty in front of the Clock Tower) are reused throughout the trilogy, to show that history repeats. Lampshaded by 2015 Biff: "There's something awfully familiar about all this."
The fundraisers trying to save the clock tower did, indeed, manage to save it.
There's also the moments which are used to serve as Fanservice — Doc Brown telling Marty "Where we're going, we don't need roads" in the third film.
Doc justifies sending Marty to 1885 in the middle of the desert by saying "You don't wanna crash into a tree that once existed in the past". In the first film, one of the first things Marty did after arriving in 1955 was (accidentally) run down one of Old Man Peabody's twin pines.
When Doc Brown makes a model of Hill Valley in the first movie, he apologizes to Marty that "this is not to scale." Lampshaded in the third movie when Marty interrupts him and says, "Yeah, I know. It's not to scale."
In all three films Marty wakes up in bed, believing his time-traveling escapades have been a nightmare. He is comforted by a character played by Lea Thompson (Marty's mother Lorraine in 1 & 2, his great, great grandmother Maggie in 3) by being told he's safe and sound in some place that jars him and reminds him it's not a nightmare after all.
The Tannen family has every reason to hate manure.
A blink-and-you'll-miss-it example occurs in the second film when Marty (indirectly) causes damage to Griff's car. Marty had previously done so to Biff's car in 1955, though in a different manner.
Car Fu: In Parts I and II, Biff tries to run Marty down with his car. Both times he crashes into a truck carrying large amounts of manure.
Doc's "Great Scott!" and Marty's "This is heavy!" Inverted in Part III, where they once exchange lines.
In the second and third films, Marty also developed the Catch Phrase "Nobody calls me chicken!" (or "yellow" in the Western setting) in response to his personal Berserk Button.
Also hilariously lampshaded in the first film: "Weight has nothing to do with this!", "There's that word again, 'heavy'. [...] Is there a problem with the Earth's gravitational pull?"
In the second and third films, Biff and Buford have good reasons to say,"I hate manure." His gang also subverts this in the first movie when they collide with the manure truck with a cry of "SHIIIIIIIIIIIT!"
Strickland seems to think that everyone's problem is that they're a slacker. Drive-by shooters peppering his home with bullets? "SLACKERS!"
Marty's variations on "What's that?" followed by a punch.
Various Tannens as well as Vice Principal Strickland tend to refer to Seamus, George, Marty, and Marty Jr. by their last names.
If you see a manure truck anytime during the trilogy, a Tannen is SURE to get covered deep in it before the movie's end.
The hoverboard: used in the second film multiple times (and in different eras), the device is used again (by Marty) to save Doc and Clara during the climactic train sequence in the third film.
The giant speaker seen at the beginning of the first movie is month's later used in the beginning of Episode 1 of Back To The future: The Game by Marty to get Doc's notebook back from Biff.
Marty's "auto accident": first referred to in Part II (during the 2015 segment), then narrowly averted during the finale of Part III.
In Part II, Marty watches a scene from A Fistful of Dollars during the 1985-A segment (at Biff's Casino). The scene is question is the part where Clint Eastwood uses steel plating under his poncho to protect himself during a gunfight. Marty then uses this trick (with a boiler plate) in Part III to survive his confrontation with Mad Dog Tannen.
Marty holding onto cars while skateboarding (skitching) in Part I, he uses the same trick (on a hoverboard) in Part II to steal the Almanac from Biff, and to Travel along a train in Part III.
In Part II Marty demonstrates his skill with a gun-based arcade game. This becomes important in Part III, giving him a sporting chance in an actual duel. This is subverted when he removes his gunbelt and lets Bufford shoot him in the boiler plate he wears under his poncho.
Marty's "chicken" problem, a key element of the sequels, is never even referred to in the first film. There is a scene from Part I where Lorraine, in the car with Marty, says "anyone who's anyone drinks." Marty then takes a sip from the bottle. Of course, this is so he can do a Spit Take, but it could also be theorised that Marty is reacting to indirectly being called "chicken". Another theory posits that the "chicken" thing is a side-effect of the altered 1985 (cf. "the ripple effect") from the first movie — Marty's father (and, by extension the whole family) is more confident; for Marty, this caused arrogant insecurity.
Related is that in Part I, Marty is concerned that nobody will like his audition tape. At the start of Part II, Marty simply assumes he'll become a rich rock star.
Though it could be argued that he's taking Doc's advice of 'achieving anything he puts his mind to' after seeing how that advice worked for George.
Contrived Coincidence: Doc Brown had the revelation for the flux capacitor on the exact same day Marty's parents met. Exactly one week later on November 12, there was the school dance where the two kissed for the first time, and lightning stuck the clock tower. It also happens that the day of the school dance was also the day Old Biff traveled back in time to change the past. This is virtually lampshaded in the second film.
Marty: That's right, Doc. November 12, 1955. Doc: Unbelievable that old Biff could have chosen that particular date. It could mean that that point in time inherently contains some sort of cosmic significance. Almost as if it were the temporal junction point for the entire space-time continuum! On the other hand, it could just be an amazing coincidence.
There is a deleted scene where in 2015, Terry (the auto mechanic who cleaned out the manure from 1955) explicitly mentions the date 11/12/55 in front of Biff. The commentary indicates this was to be the explanation behind the coincidence, but got left out due to time constraints.
The DeLorean. Anyone who grew up in The Eighties and enjoyed the BTTF movies will invariably hold a sort of unrequited love for them, even though in their unmodified form they're underpowered and don't handle too well. (Arguably, that's part of the joke — getting a real DeLorean up to 88 miles per hour is about as likely as getting it to travel through time.) In fact, the car is so iconic that these days it's practically impossible to look at a DeLorean without thinking of these movies.
Other examples: Biff's '46 Ford Super DeLuxe convertible, Marty's tricked-out 1985 Toyota 4x4, and Doc Brown's 1948 Packard Victoria convertible.
Marty, everywhen but 1985. In a way, he was also one of these in (the alternate) 1985!
Inverted with Doc, he seemed to fit in better in 1885 and was a respected member of the community (as opposed to the crazed crackpot rep he had in 1985).
Five-Temperament Ensemble: Biff (choleric), George and Clara (melancholic, the former starting out very neurotic), Doc (phlegmatic), Lorraine (sanguine), Mr. Strickland (choleric/melancholic), and Marty (sanguine/choleric).
The McFly Family: Lorraine (sanguine), George (melancholic), Dave (choleric), Linda (phlegmatic), and Marty (sanguine/choleric).
The ending scene of Part I is also the opening scene of Part II. Since Elisabeth Shue had replaced Claudia Wells as Jennifer, the scene was refilmed for the sequel. The re-shot version is nearly identical, with the only difference being that Doc Brown's face is shown this time, he gives a significant look with his eyes, and hesitates slightly before responding to Marty asking whether he and Jennifer end up as "assholes". You'll notice that they didn't even bother to match Shue's hairstyle with Wells'. Sure, most people didn't notice at first because of the four-year lag in Real Life, but if you watch the two films back to back it can be pretty jarring.
Crispin Glover also didn't return, so in all refilmed 1955 scenes in Part II, George is always seen from behind (except one shot of recycled footage viewed through Marty's binoculars).
The Spear Carrier couple ("Who is that guy?" "That's George McFly...") also get replaced in Part II's 1955 scenes, as do most of the other 1955 extras.
Speaking of 1955 extras, the character Lester ("I think he took his wallet") was played by an unnamed extra in Part I, who could be seen crouching over Biff. Obviously, as Lester became a marginally Ascended Extra thanks to Marty's interference in Part II, he was Other Darrin'd for the sequel.
Honor Before Reason: Marty is guilty of this due to his Berserk Button of being called cowardly in any way. This has done nothing but gain him more trouble than necessary and making things more difficult than they were before.
Future Marty knew that Needles' proposition was illegal and that he could get fired if he went through with it, but does so anyway when called a chicken. Of course, Future Marty is indeed found out, immediately, by his employer (who was monitoring the call!), who then fires him.
This almost gets Marty killed in Part III until Seamus and even Dr. Brown called him out on his stubbornness to not accept being called cowardly.
Hover Board: Picked up in 2015, used in both 1955 and 1885.
"Calvin Klein" is actually a subversion, as Lorraine sees it written on his underwear and believes it's his name. Marty does correct her but she still calls him Calvin. Marty bemusedly goes with it to avoid arousing further suspicion.
"Clint Eastwood", on the other hand, is played completely straight. Marty can't even back out of a duel because it would tap his personal Berserk Buttonand pre-emptively ruin Clint Eastwood's career in Westerns by associating his name with cowardice.
Immediate Sequel: Part II and III literally begin seconds after the previous ones, II after I, and III after II.
Intergenerational Friendship: Marty and Doc. Word of God explains that the friendship started when Marty was around 13-14 years old. After being told for years that Doc Brown was a dangerous, crackpot, lunatic, he snuck into Doc's lab to see for himself and instead was fascinated by what he saw in there and thought Doc's inventions were cool. Doc found him and was happy Marty thought he was "cool and accepted him for what he was". Doc then gave Marty a part-time job helping out with experiments, helping in the lab, and feeding Einstein. Read for yourself.
In Part III Marty befriends his Great-Great Grandfather Seamus. Seamus isn't much older than Marty during the time period though.
It Runs on Nonsensoleum: It's never really explained how the Mr. Fusion device Doc adds to the DeLorean from 2015 is able to generate the requisite 1.21 gigawatts of energy — not to mention undergo nuclear fusion — using an aluminum can and some other bits of garbage, though it's possibly supposed to be a comic-book style of fusion that turns matter directly into energy.
Laser-Guided Karma: For all the crap Biff and his family line tries to pull to Doc and Marty throughout the course of the trilogy, there is always a cart of manure placed just at the right moment to deliver Tannen some sweet, sweet justice.
Look Behind You: Works on most Tannens, although Griff's got some really neat cybernetic implants. He almost seems a bit surprised when he looks back and finds that his hand has caught Marty's fist. Also doubles as Schmuck Bait.
Mad Scientist: Emmett Brown is the poster child for this trope, but only when he's inventing or planning; because of great writing it's just one facet of his character. He can also be quite lucid and/or calm.
Biff Tannen: "Make like a tree and get out of here!" Lampshaded by none other than the Biff Tannen from 2015: "You sound like a damn fool when you say it wrong!"
In the now-closed theme park ride, 1955 Biff uses marbles to trip up the security staff coming after him and gleefully quips "Have a nice trip, see you next winter!" As he runs off, one of the fallen men says "It's 'see you next fall'!"
Biff thinks pointing out his malapropisms is about as funny as a screen door on a battleship!
Buford Tannen in Part III is also prone to this:
Buford: (to Marty) Eight o'clock Monday, runt. If you ain't here, I'll hunt you and shoot you down like a duck. Gang Member: It's dog, Buford. Shoot him down like a dog.
Model Planning: A Running Gag. Doc Brown builds elaborate models of city blocks or canyons to demonstrate his plans to Marty, then apologizes for "the crudity of the model". It also catches on fire, repeatedly.
My Car Hates Me: The DeLorean has a tendency to fall into disrepair at the exact moment Marty lands in another time period. Sometimes, however, justified: in the first movie, the plutonium needed to power the flux capacitor isn't available, and in the third movie, the fuel line is damaged and the gasoline leaks out, which the car needs to accelerate. The DeLorean's habit of stalling in the middle of a road has prevented possible time paradoxes: In the original movie, Marty is forced to disguise the car behind a billboard, being unable to drive it openly through 1955 Hill Valley. By stalling right before the final run towards the clock tower it delayed Marty about 30 seconds; if he had started driving when the alarm went off he would have beat the lightning bolt and been stuck in the past for the rest of his life. At the end of the film, the DeLorean stalls again, preventing Marty from interrupting the shootout at Lone Pine Mall (thus avoiding direct contact with his past self).
Nice Job Breaking It, Hero: Oh so very much. It seems like poor Marty can't go long without accidentally making the timeline worse thus requiring the need to undo the damage. "Saving" George from being hit by the car in Part I and buying the Sports Almanac in Part II were probably the worst cases. Not to mention any time Marty loses it whenever he gets called "chicken", which ends up making most situations twenty times worse.
No Man Should Have This Power: Doc Brown repeatedly promises to himself to destroy his own time-travelling technology, which finally happens at the end of Part III. (And then it almost immediately turns out that he had built a new one.)
No Pronunciation Guide: For "gigawatts". Not so noticeable to the general public at the time, but over 20 years on, the prefix "giga-" (beginning with a hard "g") has become commonplace for computer-related termsnote (Gigabyte and gigahertz likely being the most commonly known among the average computer user), so nowadays it's bound to give even non-engineers pause. (Or, make people think you're referencing Back to the Future...)
Pimped-Out Car: Doc made a time machine out of a car, and later a train, not to mention the flying abilities.
Playing Gertrude: Lea Thompson is just nine days older than her onscreen son Michael J. Fox (and Crispin Glover is actually younger than Fox!). Justified in that, for the bulk of the first movie, she's playing the character when she is Marty's age.
Pretty in Mink: In the first two films, there is a girl wearing a white fur shoulder wrap among the crowd gathering around a knocked-out Biff. This is notable because the actress is noticeably different in the two films.
Plenty from Pepsi, to the point it's amazing they didn't try to work it into Part 3. For a really good example, watch the scene between Marty and George just after the "Darth Vader" scene... notice that Michael J. Fox never completely covers the logo of his Pepsi bottle. Also, the writers had to fight to keep the "give me a Tab" gag in the first movie, because Pepsi didn't want Marty mentioning another company's soda. The futuristic Pepsi glass in Part II makes it look awfully good, though
Ditto from JC Penney, which gets shown at least three times of the trilogy.
The local Texaco station catches Marty's attention in 1955 when an army of servicemen come out to take care of one car. In 2015, Marty gawks at a giant robot operating the station.
Also meta-funny, given that full-service stations are nearly extinct in Real Life. apparently 2015!Texaco decided to resurrect the concept, but with ROBOTS!
Forget West Point. To master firearms, visit your local 7-Eleven. Foreign dubs reference Disneyland instead.
The producers also put a Zale's Jewlery ad onto a Courthouse Square bench in Part I, and Zale's neon signs in the 50s scenes of both Part I and Part II. This was done mostly as a play on the names Zemeckis and Gale.
The first piece of audio heard in the first movie is an ad for a Toyota dealer, which plays on Doc's radio. In 1955, this dealer instead sold Studebakers.
During the pre-production of the first movie, someone negotiated an endorsement deal with the state of California's Raisin board that Btt F could do for raisins what ET had done for Reese's Pieces. He came back and told the writing staff that they needed Marty to habitually eat raisins throughout the film. The execution kept getting scaled back until the final inclusion of raisins was a single poster on the park bech the drunk is sleeping on when Marty returns to 1985. The California Raisin board was not happy and demanded their money back.
Invoked by the producers, specifically choosing brands whose 1955 logos were very different from their 1985 counterparts.
Western Union will deliver a packet precisely when and where you ask. Even if it takes 70 years!
Rule of Cool: Doc made his time machine out of a DeLorean out of style. He does begin to mention that there was a reason based of the car's aluminium structure, but is cut off before he can fully explain it.
It doesn't matter what Marty and Doc do to the timeline for good or ill, Lorraine's brother Joey will end up a jailbird.
Marty seems to wake up assuming he's at home with his mother. And of course always thinks it was a dream.
"I hate manure!"
Marty's inability to get the fashions of the period right. Taken to the extreme with the cowboy outfit in Part III. To be fair, in Part III the clothes are picked by 1955 Doc, and even Marty questions their authenticity.
Whenever Marty finds himself in a new era or timeline, he can't resist walking aimlessly through the town square gawking, usually wandering right in front of an oncoming car (or carriage).
Recurring family businesses, like the Jones manure truck.
Say My Name: Doc and Marty do tons of this throughout the movies. And regardless of the decade, or even the century, Marty will be addressed by a Tannen with "Hey, McFly!."
Sci-Fi Writers Have No Sense of Scale: Time travel needs 1.21 gigawatts — the only source of which is supposedly plutonium or a lightning bolt. A lightning bolt actually generates three whole orders of magnitude more power, peaking at just over one terawatt, and a plutonium-powered fission reactor kinda wouldn't generate any power whatsoever.
Screw Destiny: Prevalent throughout the series as Marty and Doc change reality by time-traveling, but comes to a head two times. First, Doc, despite his misgivings, has his life saved by knowing how and when he is going to die, and Marty narrowly avoids a crippling accident that would change his life forever, thus changing the future they had just worked to save to the one we have now. At the very end of the trilogy, Doc says that it proves that there's no such thing as fate. Although the point about Marty avoiding his accident is less Screw Destiny and more learning a lesson while in the past/future and avoiding the situation on his own.
Two to Chitty Chitty Bang Bang: Doc owns dogs named after famous scientists (Copernicus in 1955, Einstein in 1985), just like how Caractacus Potts owns a dog named after a famous inventor (Edison). And they both make flying vehicles. The time machine train in Part III even sprouts wings like Chitty.
Another Chitty shout-out is how they both have breakfast-making machines in Part I and Part III.
It's best explained, as the filmmakers do, by paying careful attention to the Clocktower. In the original timeline the stone ledge under the clock is perfectly intact only for it to be broken when Doc climbs up there during the climax. The ledge is broken in all subsequent appearances. So yes, there was an original timeline that Marty erased through his actions in the past.
Stealth Joke: A stock DeLorean DMC-12 only got about 130 horsepower. It would go 0-60 in about a day and a half. That, of course, is before you dump a fusion reactor in the back seat, with the requisite lead shielding to keep everyone inside from dying of a radiation overdose, easily doubling the weight of the car. So the notion that the car ever got up to 88 is hilarious.
Stock Sound Effects: BTTF loves Castle Thunder, especially in the first two installments. It appears literally dozens of times, mixed in different ways, during the big Clock Tower Finale.
Take That: Biff Tannen and the Tannen family are named after then-Universal Studios executive Ned Tanen, who gave the Bobs a hard time during the making of their previous movie I Wanna Hold Your Hand.
That Was Not A Dream: Once in all three films. In each one Marty gets knocked out and comes to in a dark room being nursed to health by a woman he thinks is the mother he knows, believing his recent hardships were a nightmare. The woman inevitably reassures him in a way that tells Marty (and the audience) that it actually wasn't a dream.
Thermal Dissonance: The outer surface of the DeLorean comes out of a time jump extremely cold. If the air is humid, it promptly gets covered in ice.
Time Is Dangerous: The DeLorean has to be traveling at 88 miles per hour. Which means that unless you know what's going to be in front of you when you arrive in the new timeline, you're going to crash. By the third movie, Doc seems to be acknowledging this. Marty's a little less sure, but both times Doc assures him that the obstacle he's seeing in the present won't be there in the destination time.
Time Travel for Fun and Profit: Doc is the former, Marty and Biff seem to be the latter. Though Marty quickly gives up on the latter after Doc catches him red-handed and sermonizes him.
Title Drop: It's done several times throughout the course of the trilogy. In fact, it's become so common for Doc and/or Marty to drop the title that it's practically become a Catchphrase / Borrowed Catchphrase.
Toxic Friend Influence: Marty's "friend" Needles. Pretty much everything bad that happened to Marty in the original future was because of him.
Two-Part Trilogy: Marty's "chicken" problem was added for the sequels, as well as nemesis Douglas "Flea" Needles. Justified in that the second and third part were originally intended to be a single movie, titled Paradox.
Vague Age: Doc's age in 1955 and 1985 is never mentioned in the films. The fact that Christopher Lloyd looks exactly the same in both time frames doesn't help.
Fairly hilarious in that his age is referenced in Part II (with his "old" mask removal and his comments about having work done), so he didn't have to wear makeup. Yes, he really was given an age-up for the original 1985. Lloyd just has that old puppy dog face no matter what his age, apparently.
Villain Decay: Actually invoked with Biff. In the first film, he goes from being George McFly's bullying co-worker to the family's submissive mechanic, all because of George's punch in the 1950s. He got worse in the sequel but went back to being subservient by the end of the third movie.
Aluminum Christmas Trees: In-universe. 50s Doc initially takes this approach towards a Reagan Presidency, but comes around to it when he sees Marty's "portable television studio" (read: a camcorder), realizing that the President has to look good on TV.
Been There, Shaped History: Back in 1955, Marty McFly plays Chuck Berry's Johnny B. Goode when he steps in for Chuck's cousin, Marvin Berry. While Marty is playing, Marvin calls Chuck up so he can listen in on this "new sound." He also gives a black janitor political aspirations the exact year the Civil Rights Movement started.
The Big Damn Kiss: George and Lorraine at the dance, complete with "Earth Angel" swelling on the soundtrack, and saving their son's entire existence.
Big "NO!": Marty after Doc is shot by the Libyans.
Blatant Lies: Marty's mother in the beginning of the first movie tells him that she never went chasing after boys. When we see her younger self, it turns out that she was instantly enamored with his dad and, due to Marty taking his dad's place due to an accident, all but attempted to force herself on him.
Borrowed Catchphrase: "If you put your mind to it, you can accomplish anything." Doc never actually says it in the movie (or the rest of the trilogy), but Jennifer attributes it to him. Only Marty and George ever say it — in fact, it seems that George has adopted it as his own catchphrase at the end of the movie.
Celebrity Paradox: Huey Lewis exists in the BTTF universe, as proven by Marty's posters in his room — and so does the audition judge, played by... Huey Lewis. Even better: at the end of the movie, Marty's clock radio plays "Back in Time" by Huey Lewis and the News. The song was specifically written for (and contains a TON of references to) a little movie called Back to the Future.
At the start of the film, Marty is conveniently given a flyer by a woman who (along with other volunteers) is attempting to raise money to save the historic clock tower. The scene is played for laughs, but the flier contains crucial information on how to return to the future, including the exact date and time that the clock tower was struck by lightning.
Lorraine tells the kids that if her father hadn't hit George McFly with his car in 1955 before the dance, none of the kids would've been born. She also says that she and George fell in love after they had their first kiss at the dance. It's all seemingly useless information that parents just say for no reason, right?
When Marty hides the DeLorean shortly after arriving in 1955, he is shown putting the walkman he later uses as part of his alien impersonation in the car for no other reason than to establish he has it.
Chekhov's Gunman: Dixon, the guy who cuts in on George and Lorraine at the dance, was previously seen kicking George around when he had the "Kick Me" sign on his back.
Marty is at Doc Brown's house, and thinks he will be on time for school, only to discover all his clocks are twenty-five minutes slow.
Doc Brown proves to Marty that the time machine works by syncronizing watches with a digital clock he attaches to his dog, then sending the dog one minute into the future. When the dog shows up again, his clock is a minute slower than Doc's.
Clown Car: Biff's goons make the mistake of insulting one of The Starlighters outside his Cadillac, causing four others to exit the car.
Comically Missing the Point: Played with, perhaps. It initially sounds as if Marty is amazed by the time machine. Then he adds the phrase, "out of a DeLorean?!"
Marty McFly: Are you telling me you built a time machine... out of a DeLorean?!
Common Knowledge: In-universe example, when Doc Brown is showing Marty how to set the target date on the time machine:
Doc Brown: Say you wanted to see the signing of the Declaration of Independence." (sets date to JUL 04 1776)
The Declaration was not signed on this date.
Doc Brown: Or witness the birth of Christ!" (sets date to DEC 25 0000)
Jesus would not have been born in December. Plus "0000" isn't even a year on any calendar (the year before AD 1 was 1 BC). Both of these were intended as jokesby the filmmakers who knew full well that neither of these dates were accurate. Nobody got it.
Contrived Clumsiness: Marty "accidentally" trips Biff when they're in the diner in 1955 Hill Valley.
Contrived Coincidence: The lightning strike just happens to take place within a week of the day Doc Brown came up with the idea of the time machine. If it had happened a year or two later, Marty would have had to wait all that time before he can go back to the future, and if had happened before Doc's eureka moment, Marty can't go back until they acquire some plutonium.
Covert Pervert: Believe it or not, Doc Brown. In a deleted scene, the audience is shown some of the contents of the briefcase 1985 Doc was planning to take with him during his time travel expedition; among them was a Playboy Magazine. Upon finding it, the 1955 Doc responds thus:
1955!Doc: Suddenly the future's looking a whole lot better!
Damsel in Distress: Invoked and then played straight — Marty's plan is to stage an Attempted Rape of Lorraine (his own mother) so that George can intervene and win Lorraine's affections. However, when Biff interrupts the staged attempted rape and tries to actually rape Lorraine, it's up to George to save the day, which he does, achieving the desired result.
Easily Forgiven: While Biff in the altered timeline appears to have become a harmless, eager-to-please Gentle Giant who is barely recognisable as the bully he used to be, both George and Lorraine seem to be remarkably grudge-free about him trying to rape Lorraine.
First Kiss: George and Lorraine have theirs during the Enchantment Under The Sea Dance, while the band plays "Earth Angel".
555: Doc Brown's phone number, as well as Jennifer's grandmother's.
Florence Nightingale Effect: Discussed Trope. How Marty's mother fell in love with his father... and how Marty accidentally ends up replacing his father in her affections. Squicks Marty, repelling him, and inadvertently making him even more attractive to her. Especially after he defends her from Biff in the school lunch room. Lampshaded by Doc.
Stella keeps taking off Milton's coonskin hat, while Marty is taking in the surroundings of the Baines' dining room.
When Biff says "Make like a tree... and get out of here", one of his henchmen turns his head towards him, and his eyebrows slowly try to crawl their way up to his hairline.
After Doc Brown is asked by the police officer for a permit for his "weather experiment" the shot moves to Marty slipping his letter into Doc Brown's jacket. In the background the Doc is looking for the permit... in his wallet. In the novelization, and in a deleted scene, the "permit" is a $50 bill, which was worth quite a bit in 1955.
Garage Band: Marty McFly's band, which auditions for the school dance.
Audition Judge: Hold it, fellas. I'm afraid you're just too darn loud.
Genius Bonus: Biff and his goons are very intimidated by the Starlighters, saying "We don't want to mess with no reefer addicts." To many viewers, knowing that marijuana is not addictive and does not cause violent behavior, this may make them seem like cowards. Those familiar with the time period, though, will know that it was the era of Reefer Madness and the goons had just bought into the propaganda. May double as a Parental Bonus.
Biff, when he sits at Lorraine's table and tries to grope her.
Biff: You want it, you know you want it, and you know you want me to give it to you.
During the scene where Marty and George are going over the plan of how they're going to get George with Lorraine we have this exchange while George is doing his family's laundry:
Marty: Because George (voice begins to stutter) Nice girls get angry when not-nice guys take advantage of them. George: Hoh! You mean you're going to touch her on her— (holding a bra in his hand)
When the teacher gives Marty's girlfriend her tardy slip, she holds it up between them, her middle finger very prominent.
God Guise: Marty uses his radiation suit and Walkman stereo to dress up as "Darth Vader from the Planet Vulcan". He frightens George and threatens to melt his brain if he doesn't take Lorraine to the school dance.
Improvised Lightning Rod: Doc Brown uses the Clock Tower as a lightning rod to gain the 1.21 gigawatts of electricity the DeLorean needs to get back to the future.
Improvised Zipline: Doc Brown uses the heavy duty electrical cable attached to the clock tower as a line to reach the ground quickly and fix a break in the line.
Incest Is Relative: Parodied, in that whilst Marty knows who Lorraine really is, she has no idea as to his true identity. Luckily for Marty, Lorraine likens kissing him as to kissing her brother.
In Spite of a Nail: Only Doc, the McFly family and Biff Tannen have changed upon Marty's returns to 1985; everything else is exactly the same as "before". Notable exception: Before Marty travels through time, he meets Doc in the parking lot of the Twin Pines Mall. After Marty runs over one of Old Man Peabody's pine trees in 1955, he finds himself and Doc fleeing the Libyans at the Lone Pine Mall.
Old Man Peabody: Take that, you mutated son of a bitch!
Just Keep Driving: Used as a one-off joke when Marty escapes the wrath of Old Man Peabody and steps on the entrance to the construction site of Hill Valley. After attempting to ask a passing middle-aged couple where he was, the woman starts to freak, tapping her husband rapidly on the shoulder and yelling "DON'T STOP OR WE'REDEAAAADDD!!!"
Kid from the Future: Marty, although his parents know nothing of who he really is. Lorraine is enamoured with him due to his cavalier attitude (and the "Florence Nightingale effect") and George initially thinks he's a pushy pest who keeps following him around.
Let's Get Dangerous: Bumbling fretful Doc, when he sees that he accidentally unplugged the other end of the cable, sucks it up, and ziplines off the clock tower in the middle of a storm.
Letting the Air out of the Band: Happens the minute Biff angrily marches in to throw George out of the diner. Apparently, someone in the room had a good sense of dramatic tension to unplug the jukebox at that exact moment.
Limit Break: George punching out Biff after Biff laughs at him and pushes Lorraine to the ground.
Parental Bonus: After Marty wakes up from being knocked out in 1955, he learns that his pants are "over there... on (Lorraine's) hope chest". Many people who were born after the 1950s may not understand what a hope chest is. It's a chest that young girls used to keep in preparation for their marriage. The joke here is that Lorraine was already fantasizing about marrying the young man that she did not realize was her future son.
The Peeping Tom: The then-teenage George McFly spies on his future wife, Lorraine, from a tree next to her window. This becomes a crucial plot point as this is the point where Marty alters history. When George falls out of the tree, Marty pushes him out of the way of an oncoming car... accidentally preventing his parents original meeting.
Percussive Maintenance: Marty bashes his head against the DeLorean's steering wheel when it refuses to start. At this, the ignition miraculously turns on.
Police Are Useless: Aside from Attempted Rape above, Biff in 1955 also makes multiple threats of assault throughout the movie, and in one scene attempts to commit MURDER, and nobody even seems to think that he's doing anything illegal.
The Power of Rock: Subverted: Marty's guitar solos produce indifference in their audience, though played straight in the same scene while actually singing the song.
Marty: I guess you guys aren't ready for that yet.
Reliably Unreliable Guns: Marty is saved repeatedly from being shot by Libyans because their rifle jams. They are shooting an AK-47, which are famed for their reliability even under the harshest conditions. However, we do see them simply trying to clear the jam rather than abandoning the gun immediately.
Ret Gone: Dave, Linda and Marty in the photograph.
Rule of Cool: How did Marty play a song that requires guitar components that didn't exist in the 50's? And how did the band learn to accompany him so perfectly? Who cares, it's awesome!
Scary Black Men: "Who you callin' "spook", peckerwood?!" Biff's gang seems more afraid of the copious amount of pot smoke billowing out of the car than anything else: "I don't wanna mess with no reefer addicts!"
Science Marches On: Played with in Doc Brown's apparently sincere assumption that "plutonium is available in every corner drugstore" in 1985, among other assumptions.
Doc declares he has to send Marty "Back! To the future!"
And again at the end of the movie when Doc comes back from 2015, to pick up Einstein and go back to... you know.
Took a Level in Badass: George standing up to Biff is a critical moment thats fill him with self-confidence and changes the destiny of his whole life and family.
Turn Out Like His Father: Played with in every possible way. People tell Marty he's going to be a loser like his dad, then the past changes and his dad is not a loser but Marty is still destined to be a loser, then that future is possibly avoided presumably letting Marty succeed at a creative pursuit like his dad.
The Libyans. They come charging in, shooting at Doc Brown from the van, they hit a kiosk and the van tips over. Then Marty, Doc, and the film forget about them completely, even having a joyful reunion at the end without bothering to see what's going on with the homicidally angry terrorists in the van a few yards away.
Since said van was travelling at around 80mph when it hit the kiosk, it's probably a safe assumption that the Libyans are at the very least unconscious, and more likely dead.
What happened to Doc Brown's remaining plutonium? Did he use it all before fitting Mr. Fusion, or did he just throw it in a bin somewhere? (Which, given the general recklessness he displays during the trilogy, is not that much of a stretch.)
Who's on First?: Marty's attempts to get a Tab, and then a Pepsi Free, at Lou's Cafe in the 50's.
Lou: You want a Pepsi, pal, you're gonna have to pay for it!
You Keep Using That Word: At least from 1955!Doc's point of view, as he thinks that Marty's use of the word "heavy" still applies to weight and measurements, when, from Marty's point of view, he's just using the slang term for something that has a deep, powerful impact, whether philosophical, intellectual, or emotional.
Angry Black Man: The dad of the family living in Marty's house in the alternate 1985. To be fair, he did catch Marty breaking into his daughter's room, so the anger was justified. His wielding a bat made him into a Scary Black Man.
Apocalypse How: Several potential paradoxes in this film could destroy the entire universe, which would be a Class X-4, worst-scenario. (The effect might actually be localized to their own galaxy, which is a Class X-3.)
As Long as It Sounds Foreign: Future!Marty works for a "Mr. Fujitsu"; "Fujitsu" is the name of a Japanese company, but it's short for "Fuji Telecommunications Equipment Manufacturing"note (Fuji Tsuushinki Seizou if you're wondering, but parsed down to Fuji-Tsuu Kabushiki-gaisha(Stock Company) nowadays), not a surname.
As You Know: Played with cleverly; Griff's gang drops a piece of exposition as something they expected Marty Jr. to know, but young Marty Sr. doesn't.
Whitey: Hey McFly, you bojo! Those boards don't work on water! Unless you got POWAH!
Book and Switch: Biff hides a girly magazine inside the dust jacket of the sports almanac, which Marty mistakes for the real thing. An earlier scene in 2015 established the dust jacket for the purpose of this scene.
CPR (Clean, Pretty, Reliable): Subverted — Biff comes to just as someone (named "CPR Kid" in the credits) asks, "What's CPR?", and Marty knocks Biff out again. Amusingly, the "Universal Animated Anecdotes" included in the DVD had to clarify that CPR does not mean punching someone in the face.
From the Actual DVD Commentary: No, kids, that's not CPR.
Cue the Rain: It starts raining soon after lightning strikes the time machine and Marty is left stranded in the past again. Justified, of course, in that this is the same storm that played a role in sending Marty back to the future in the first film, and there were all sorts of signs of a storm brewing the whole time anyway.
Young Biff: Why don't you make like a tree and get out of here? Old Biff: (smack) IT'S "LEAVE", YOU IDIOT! Make like a tree and LEAVE! You sound like a damned FOOL when you say it wrong!
Dramatic Irony: In alternate 1985, it is established that Lorraine ends up marrying the obscenely rich Biff. Then in 1955, when Biff torments Lorraine, she responds that she wouldn't marry him even if he had a million dollars.
Exact Eavesdropping: Marty and Doc have the misfortune of being stalked and heard by Biff during their argument about time travel for profit.
Fake Shemp: Word of Bob Gale says that Crispin Glover got an ego and started making outlandish demands for his return in the sequels. Gale and Zemeckis decided to forget Glover and get creative by using a double actor and some nifty tricks with stock footage and computer effects. It backfired on the producers and Glover sued. The suit was settled out of court and the Screen Actors Guild revised their rules on stock footage use.
When the "DESTINATION TIME" readout on the time circuits flash to "JAN 01 1885 12:00AM" and Doc remarks "Damn, gotta fix this thing." By the time Marty catches up with Doc in the third part of the trilogy, he had already been there for nine months.
Biff-A is watching A Fistful of Dollars, and crows when Clint Eastwood showed he was wearing a stovetop under his poncho, "A bullet-proof vest! Ingenious!" Guess how the showdown in III is resolved?
Heroic BSOD: Doc at the end, when all of the implications of Marty's return from the future hit him. He faints.
Hesitation Equals Dishonesty: At the end of the first film, Doc lies about Marty and Jennifer not being "assholes in the future." When the scene was reshot for the start of the second film, Doc hesitates before answering their question.
History Marches On: The USA Today paper reporting on Marty Jr.'s arrest also reports that "Queen Diana" is scheduled to visit Washington, D.C. Of course, Diana tragically never lived to see 2015, let alone become queen.
I Want My Jetpack: Hoverboards, holographic movie posters, auto-adjusting clothes, ubiquitous robots, dehydrated pizza, weather reports accurate to the minute, commercially available fusion reactors small enough to power car, flying cars in such numbers to cause traffic jams...From the perspective of reality in The New Tens, this stuff had better get a move on, though as the Zee Rust entry below shows, they were deliberately going overboard with this stuff.
So help them though Nike seems pretty determined to get those self-lacing shoes out by 2015.
Japan Takes Over the World: 2015 was partly based on the assumption that the Japanese economy would have overtaken the US one by the early 21st Century.
Kick the Dog: There's a scene in 1955 where Biff gets a hold of a ball belonging to a bunch of kids, and while listening to them plead to have it back, mocks them and then throws it onto a second story balcony.
Male Gaze: While trying to keep track of Marty, Jr. through some Star Wars-esque binoculars, Doc Brown's line of vision constantly shifts to the very busty women that passed by him.
Married In The Future: Doc takes Marty and Jennifer into the future where she sees their future home and kids, but everything else sucks. In Part III, however, Marty manages to avert the event that led to that timeline.
No Paper Future: Averted, at least in the case of faxes and "dust-repellent paper".
Not So Great Escape: Marty finds himself trapped in Strickland's office while trying to retrieve the almanac and has to desperately hide beneath the desk and in other spots to avoid being discovered, including getting his hand crushed by Strickland's chair.
However, this is later subverted when Old Biff steps out of the taxi, and the driver charges him $174.50 for the ride. While this is still expensive relative to the time of the movie's release, it suggests that a future taxi ride only costs three sodas.
Or it suggests that a bottle of Pepsi doesn't cost a full fifty dollars, but that Doc gave it to Marty just in case. He does wind up able to buy the Almanac as well, after all.
Ridiculous Future Sequelisation: A holographic advertisement for Jaws 19, directed by Max Spielberg, with the tagline: "This time it's really, really personal." All Marty has to say is, "The shark still looks fake." Well, to be fair, the very first thing he has to say is, "AAAAAAAAHHHH!"
Blink and you'll miss it, but the StarCar from The Last Starfighter can be seen in 2015. You can catch it just as the Jeep rockets down from the sky in the chase sequence.
Shown Their Work: The college football scores Biff hears on his car radio are the actual scores of actual college football games played on Saturday, November 12, 1955 — except, oddly, the Texas A&M-Rice matchup, which the radio announcer says A&M won 20-10 when the actual score was 20-12.
Marty: Let's land on him, we'll cripple his car. Doc: Marty, he's in a '46 Ford; we're in a DeLorean. He'd rip through us like we were tinfoil.
Absolutely Truth in Television. DeLoreans feature a fiberglass body overlaid with relatively thin sheet metal (which would sometimes crack during manufacturing). Some of the crash tests show an unbelievable amount of crumpling when hitting a solid wall, so the Doc is quite accurate with his observation.
1955!Doc: No! It can't be; I just sent you back to the future! Marty: No, I know; you did send me back to the future. But I'm back — I'm back from the future. 1955!Doc: Great Scott! (faint)
To Be Continued: Audiences were upset they actually showed scenes from III. Thanks for the Spoiler Alert, Zemeckis. Deliberately done to assure audiences that the last chapter would be finished in a matter of months, not years.
Took a Level in Badass: 1985-A Mr. Strickland. Living in a crapsack world infested with trigger-happy gangs doesn't help.
Trailers Always Spoil: The preview for Part III includes a shot revealing that Marty (still in his cowboy gear) eventually gets back to Jennifer, which is one of the trilogy's major subplots.
Trophy Wife: Marty's mother has been coerced into becoming Biff Tannen's trophy wife, complete with unwanted breast augmentation. Though Marty is eventually able to Set Right What Once Went Wrong, the viewer sees that she would have eventually shot him to death.
Unintentional Period Piece: A weird case; the Cafe 80's scene, (remember, this movie was made in 1989), invokes this trope directly. The result was rather bizarre at the time, and still is. This is probably intentional, as Doc referred to it as "one of those nostalgia places that were not done very well."
Unstoppable Mailman: The Western Union man at the end manages to arrive at exactly the time he was told to. Justified in that he and other mail carriers were holding bets on whether or not Marty would be there.
Video Phone: The Future McFly household's video phone is connected to the television set. Personal information about the individual on the other end of the line is scrolled through on screen, including name, age, occupation, home address, spouse, children, and assorted hobbies and preferences. Video calling is also sponsored by AT&T.
Even though Doc's copy of USA Today is a localized edition (the joke seems to be that they took over the whole newspaper industry), "Youth Jailed" is not exactly cover story material. Especially when you see the other stories from that day.
Similarly, though perhaps less severe, later in the movie we see the papers from the alternate timeline where "Hill Valley Man Wins Big at Races" is the main headline on a 1958 copy of the local paper, over "Khrushchev Becomes New Soviet Premier." In the same scene we also see that "Emmet Brown Committed" has pushed a story about Nixon running for office for a Fifth time (!!) and vowing to end the Vietnam War. It seems the local press in Hill Valley really doesn't care for anything going on beyond their little town! Truth in Television: a lot of small-town newspapers are like this.
Zeerust / Twenty Minutes into the Future: Done on purpose; the filmmakers didn't want to try to accurately predict the future, so they just combined Jetsons-esque devices with some obvious jokes (the McFlys have a fax machine in every room of their house, which apparently all print the same message at once).note (A thermal paper fax machine, at that. Some of the printouts have been seen at conventions years later, already decaying due to temperature exposure.)
Ironically, some of their predictions actually came pretty close. Things like 16:9 flat-screen TVs with the ability to watch multiple shows at once don't sound too crazy in a world with Google TV. Hell, think about Marty Jr. watching about eight shows at once, then ask yourself: how many tabs do you have open in your browser right now? (Of course, they completely missed the internet, but so did nearly everyone.)
Enforced by Major League Baseball- they could have sent the Miami Marlins to the American League, potentially setting up a Cubs-Marlins World Series in 2015, but instead chose to send the Houston Astros to the AL.
The idea of a robot dogwalker (like Marty sees in Hilldale) doesn't seem so farfetched, given the growth of the personal robot market in recent years. The flying thing's unlikely, though.
Action Film, Quiet Drama Scene: The scene in the saloon towards the end, which you could compare to High Noon. Buford and his gang have Marty trapped, and Buford is counting down to a showdown. Doc is unconscious. Marty is visibly struggling with whether or not to fight Buford, as Seamus looks on.
Mary Steenburgen stars as a woman who falls in love with a time-traveler, just like in Time After Time. It's also worth noting that her first role was in a Western, where her character was being romanced by a man played by — Christopher Lloyd! He lost her to Jack Nicholson in that one, though.
Also worth noting is in this film, she is a 19th century woman who falls in love with a 20th century time-traveler, the opposite of her role from Time After Time, where she was a 20th century woman who falls in love with a 19th century time-traveler.
The three old-timers at the saloon are all played by veterans of westerns: Dub Taylor, Harry Carey, Jr. and Pat Buttram.
Amplified Animal Aptitude: Doc's dog Copernicus seems to at an almost human level of intelligence at times. For starters, after Doc finishes reading the letter that his future self wrote to Marty, Copernicus seems to be rather sad about Doc being Trapped in the Past. In addition, Copernicus is the one who discovers Doc's tombstone, and he seems to realize what it says.
Big Damn Heroes: Marty defeats Buford Just in Time to stop him executing Doc; meanwhile, Doc swoops in Just in Time to save Marty from getting hanged AND Clara from falling. Lampshaded by Marty: "Why do we have to cut these things so damn close?"
Bittersweet Ending: Averted. Initially, it looks like a Bittersweet Ending because Doc Brown is stuck in the 1800s, but he is with the woman he loves, and Marty is reunited with Jennifer in his own time, but it looks like he will never see Doc Brown again. However, they are reunited in the end anyway because the Doc builds a steam-powered train time machine.
The Blacksmith: Doc sets himself up as one when trying to repair the DeLorean until giving up and hiding it in the Delgado Mine. By the time Marty comes to 1885 to rescue Doc, he's still operating as a blacksmith.
Bullet Dancing: Spoofed, as Marty turns this into the Moon Walk. And it is awesome. Buford and his gang are so dumbfounded that they just watch in disbelief. Then he hits Buford with a spittoon, and all hell breaks loose.
Dub-Induced Plot Hole: Not exactly a plot hole per-se, but Doc's last line "Already been there (the future)" is sometimes dubbed to "I already am in the future." The original line is meant to be the lead-up for the Time Train's flying capability. The dubbed line turns it to a character moment, showing that whenever he can go, his heart is still in the Old West. Both versions work in their own way, though the dubbed version makes the train's flight something of an Ass Pull.
Dude, She's Like in a Coma: Played to be romantic rather than creepy. When Marty gets back to 1985, he sets out to Jennifer's house to check if she's alright from the events of Part II, and finds her asleep on her front porch. After trying and failing to wake her the old-fashioned way, he kisses her on the lips, where-upon she wakes up.
Early in the film, Doc, confused on who "Clara" is, denies to Marty that he knows that any woman by that name and dismisses the notion of love at first sight as "utter romantic nonsense". Then the Hill Valley 1885 mayor rolls in and talks to Doc, reminding him that at a town hall meeting he agreed to meet the new schoolteacher. Doc breezes over a majority of the details, until the mayor mentions her name, "Clara Clayton", to which Doc freezes in horror and gives the same Oh Crap face previously used for comedy a more serious twist.
When Marty is reunited with Doc, who is currently talking down Buford, they are discussing about a recent shoeing job done on one of Buford's horse's that, because it went afoul, Buford thinks Doc should be held responsible. When Buford mentions the prices of the new horse and whiskey he bought that day, "$75 for the horse, $5 for the whiskey", Marty quickly does the math and whispers in shock, "That's the eighty dollars!" note (According to the tombstone Marty found, Doc was "shot in the back by Buford Tannen over a matter of eighty dollars.")
Train Engineer: Is this a hold-up? Doc: No, it's a science experiment!
For Want of a Nail: A non-standard example for a time-travel story; the fuel line being punctured by rough terrain leads to the complex plot of getting the DeLorean up to time-travel velocity. One would think that packing an extra can of gasoline for a trip to pre-petroleum times would be a no-brainer, but 1955 Doc is not as Genre Savvy about time travel as his 1985 counterpart. People do get confused into thinking it was the Indians because Marty pulls an arrow out of the bodywork immediately before noticing the dripping fuel under the car.
Freeze-Frame Bonus: When Needles challenges Marty to a race near the end, we are given two shots of Marty shifting gears in his truck. First, he moves the gearshift selector to the far left and up for 1st gear. Then, we see him shift again all the way right and down, for Reverse.
When Doc and Clara return in the time machine train, Doc in the foreground tells Marty and Jennifer to make their future a good one. In the background, for whatever reason, the child playing Verne points to his crotch. It's been hypothesized that the child actor was trying to signal to someone (possibly director Zemeckis) that he needed to pee.
Marty complains that Clint Eastwood never wore such a ridiculous getup, and Doc doesn't know who that is. They have this conversation in front of a drive-in theater, with a poster for Revenge of the Creature, Eastwood's first film.
Going Native: Doc has adjusted to life in 1885 very well. Well, he did mention how the Old West was his favorite time period.
Greek Chorus: The three old-timers who hang out at the saloon.
Honest John's Dealership: One never actually shows up in the film, but we do see a billboard in 1885!Hill Valley advertising a business called "Honest John's Dealership! Quality horses bought and sold!"
Again, keeping similar jobs in a family, The Statler family owns the horse dealership in 1885, an Oldsmobile dealership in 1955, and a Toyota dealership in 1985.
I Lied: In a deleted scene, Buford says this after shooting Marshall Strickland.
In Spite of a Nail: Again, the new timeline has barely changed toward the end, except that the ravine the train is supposed to cross over is originally called "Shonash Ravine" but was supposedly called "Clayton Ravine" after Clara fell in it (which Marty and Doc stopped from happening). After the train crashes into the ravine and Marty goes home at the end, the DeLorean rolls along the tracks and past a sign that says "Eastwood Ravine". Marty was going by Clint Eastwood in 1885, so "Clint Eastwood" fell into the ravine instead.
Instant Death Bullet: Subverted. Marty and Doc both assumed that Doc will be shot on Monday, because that's when he dies. Turns out he got shot on Saturday in the original timeline, and didn't succumb to his wound for another two days.
Instant Sedation: We find out Doc reallyCan't Hold His Liquor when he swallows a shot of whiskey and instantly passes out - the whiskey has barely gotten in his stomach, much less into his bloodstream or brain to have any effect.
Buford likes doing this, apparently. In a deleted scene, he shoots Marshall Strickland in the back too.
Irony: Biff-A idolizes Clint Eastwood. Buford, however, thinks the name is utterly ridiculous and doesn't hesitate to call "Eastwood" a coward and kill him on sight.
In addition, when Marty is preparing to go back in time at a movie theater, he is afraid that he'll crash into the painting of a group of Indians underneath the screen. Doc reassures him that when he goes back in time, the theater won't have been built yet and the Indians won't be there. As soon as he arrives in 1885 however, he nearly crashes into a group of very real Indians who just happened to be riding through the area at the time.
Like Parent, Like Spouse: The "Bobs" (Zemeckis and Gale) claim that McFly men are attracted to women who look like Lea Thompson, to explain why Marty's paternal great-great-grandmother looks so much like his mother. In addtion, Claudia Wells (and later, Elizabeth Shue) both look a bit like Lea Thompson.
Logo Joke: Old Universal logos appear during the opening, in honor of the 75th anniversary of Universal Pictures Film Company, Inc.
Love at First Sight: Doc and Clara, though Doc's skeptical before they meet when Marty says that this happened with him and Jennifer.
Lyrical Dissonance: An odd example, considering you don't actually hear the words to the song, but the first song played at the hoedown is an uptempo version of "Nearer, My God, to Thee" of Titanic infamy. The song is traditionally very somber, so it's odd to hear such a positive version.
May-December Romance: If you're being very gentle with how old Doc must be, he still must be at least twice Clara's age. Of course, the visit to the rejuvenation clinic in 2015 probably added thirty or forty years to his life, so it's not as unfortunate as it sounds. They also replaced his spleen and colon.
Mood Whiplash: One of the reasons why the scene where Buford shoots Marshall Strickland was removed. The producers thought it was too depressing, and after doing it, it didn't seem right that Buford not die. They were worried it would make audiences want Marty to kill Buford, and he can't, because Buford needs to live long enough to extend the Tannen family line. In 1985-A in Part II, Buford was explicitly identified as Biff's great-grandfather, meaning Marty couldn't risk killing him. This leaves a minor plot-hole in the scene when Bufford is arrested by the Deputy, instead of the Marshall.
At the end of the movie, right after Marty makes it back to 1985, we see a sign for "Eastwood Ravine," and it looks like the DeLorean has triggered the train crossing gates at a traffic intersection — both funny moments. A few seconds later, a modern train destroys the DeLorean — one of the most iconic cars in cinematic history — and Marty realizes that this strands his best friend in the past.
Oh Crap: The look on Doc's face when Buford comes to shoot him on Saturday, and he realizes that just because he died in the original timeline on Monday doesn't mean that's when he got shot. This is lampshaded by Buford by explaining that his derringer, despite its small size and ability to only shoot one shot, causes a slow, agonizing death.
Oireland: Seamus and Maggie McFly, complete with stereotypical (and non-existant in reality) accents.
Ominous Pipe Organ: Heard when Marty confirms to Doc that he returned to 1955 even after being sent to the future. In-universe: backed up against the organ in his house in terror at Marty's apparition, Doc's groping hands just happen to play a series of dissonant and ominous chords.
Prophecy Twist: The photograph of Doc's tombstone accurately predicts the date and the cause of his death if history continues on the same course. What Marty and Doc don't realise is the cause (being shot in the back) wouldn't necessarily happen on the same day as the resulting death. Mad Dog Tannen subsequently shows up to kill Doc two days earlier than expected.
Reality Is Unrealistic: Seamus McFly frequently is ridiculed for wearing a bowler hat instead of the typical Wild-west cowboy hat everyone else has on. The comedy in this may well have been intentional, but bowler hats were actually the popular style back then. The cowboy hat we know today (the Stetson)? Back then, it looked like this.◊
Schizo Tech: Invoked; by the end of the film, the DeLorean is a 1980s car, whose time circuits are powered by a 2015 fusion device, with jumps calculated by a computer built of 1955 vacuum tubes, running on 1885 train wheels.
There's also the time machine built out of a train which the Doc and family later arrive in, playing it somewhat more straight.
The Slow Path: The DeLorean does this — mothballed by Doc in 1885 so Marty can retrieve it 70 years later in 1955.
Spear Carrier: The train engineer who asks if it's a robbery and Doc answers, "It's a science experiment."
Steam Punk: Doc's custom sniper rifle, the time train from the end, as well as Doc's refrigerator in the blacksmith shop. The sheer size and complexity of the refrigerator, along with the difficulty of getting a conventional steam locomotive up to eighty-eight miles per hour (easily done with an internal combustion engine), illustrate more "realistic" applications of Steam Punk tech. The time train at the end throws all realism out the window, but as Doc once said, "If you put your mind to it, you can accomplish anything."
Unusually Uninteresting Sight: The Indians' reaction to the DeLorean when Marty arrives in 1885. True, they are being chased by the US Cavalry and one of the Indians hits the DeLorean with an arrow, but you would think at least a few of them would stop dead, especially since they just saw the DeLorean appear out of thin air in a flash of light.
Urine Trouble: The first McFly born in America greets his future descendant with this trope.
Voice Over Letter: Subverted. At the end of Part 2, Marty receives a letter from time-displaced Doc in 1885, and reads the first few sentences of it aloud. In Part 3, the entirety of the letter is read by Doc. What makes this case different is that it's read by 1955's Doc, who won't write the letter for another 30 years, and so is reading it for the first time along with the audience.
Only Child Syndrome: Both Marty and Lorraine have numerous siblings that aren't that important to the plot, and of course Doc and Clara have two children together. George and Jennifer are only children however. As far as we know, anyway — we never actually met George or Jennifer's family. In the novel, we meet George's family and it is implied he is an only child.
Part 1: Lou: "A colored mayor, that'll be the day."
Also in Part 1, one of Biff's gang calls one of the band's members a "spook", which is a largely forgotten racial epithet for a black person.
The band members respond by calling him "peckerwood", which was likewise a racial slur for a white person.
Part 3: Saloon Patron: "Where'd you get that outfit, off'n a dead Chinee?"
San Dimas Time: "If only I had more time... wait a minute, I have all the time I want; I got a time machine!" He then proceeds to screw it up by giving himself only a few extra minutes, thus allowing him to make it back to the mall parking lot just in time to see Doc get shot.Justified in that he hadn't counted on the starter for the DeLorean failing. Again.
Time Crash: Doc is concerned that causing an unresolvable time paradox or having someone encounter his or her past self could potentially destroy the timeline.
What Year Is This?: Marty looks at newspapers instead. And of course, the DeLorean has a bright digital display that tells you exactly when you are.
Although Doc Brown's letter at the end of Part 2 sort of plays this trope straight (the only part of the Trilogy to do so), though Rule of Cool applies for obvious reasons.
The 1955!Doc averts this. He specifically sends Marty back to a point after 1985!Doc left the letter with Western Union. As can been seen in Part III, they didn't do anything about it, which allowed for normal 70+ year delivery. ...And the Western Union guy lost the bet!