The fourth draft screenplay of Back to the Future was finalized on October 12, 1984 by Robert Zemeckis and Bob Gale. The fourth draft is most similar to the finished product, with minor details not shown in the film, altered, or removed altogether. There is the possibility that a fifth draft exists that cleaned up all the minor changes between this draft and the final screenplay.
- Mr. Strickland makes his first appearance.
- Doc's clocks all go off at the same time, however it is only for aural pleasure and not for the sake of a science experiment.
- Doc speaks of Twin Pines Mall and the Peabody farm in 1955.
- The DeLorean time machine appears.
- While parked outside town, he turns on the radio and picks up "Papa Loves Mambo" by Perry Como, which later appears in Back to the Future Part II in Biff's car.
- Details for Courthouse Square in 1955 appear in the draft, including an appliance store that sells "modern" small appliances, a travel agency advertising "Fabulous Vacations in Cuba", and a bank that advertises "Passbook Savings at 2¼%".
- After Doc's first suggestions, he randomly spouts that Marty could drive across the country at 88 mph and hope that he gets struck by lightning.
- The scene with Marty dressed as an alien to scare George was included, however, it had much more dialogue that would have seemed unnecessary in the film. The extra dialogue appears in the novelization and an extended scene appears on the DVD where he knocks him out with chloroform.
- Betty and Babs are named.
- The first scene is inside a classroom showing footage of a nuclear test with Marty listening to his Sony Walkman.
- Marty's girlfriend is still Suzy Parker.
- Marty is sent to Strickland's office and is sentenced to detention.
- Marty escapes detention by setting off the smoke alarm. (Appears in Back to the Future novelization)
- The clocktower is frozen at 10:02.
- Marty wants something different than the 4 x 4 truck ("Hey, check out that tricked-out Supra. Now THAT'S a car. Someday, Suzy, someday... ").
- Suzy indicates that she has a shrink, and that Marty is "sexually repressed" and has "emotional anxieties".
- Marty is less respectful when talking about, or to, his parents, or even about Doc. When his mother talks about his father's shyness, Marty quips "I'll bet you had to practically jump his bones."
- The clocktower lady says "We at the society feel that it's a landmark of scientific importance, attesting to the power of the Almighty.", which might sound out of place in the final movie.
- Doc Brown pulls up in a RV filled with clocks, video equipment, and a lead canister with purple radiation symbols on it.
- Marty is aware that Doc broke into a power plant. (This role later shifts to the Libyan terrorists.)
- Marty tells Jennifer/Suzy that he first met Doc when he showed up at his door and asked him to clean his garage and paid him $50 a week, beer, and access to his record collection. (Showing up at his door might be explained with a predestination paradox.)
- Doc was "one of the world's greatest nuclear physicists".
- Dave works at McDonald's, instead of Burger King.
- George gives a small speech to his son about how a record deal would cause more problems, driving Marty to give up.
- The vanity license plate reads NOTIME.
- Einstein leaves at 1:02 A.M.
- The flux capacitor is known as the "temporal field capacitor".
- Rather than leaving from October 26, 1985, Marty departs from October 5, 1985
- In an added scene, Mrs. Peabody rubs her head after Marty leaves the farm and the family believes she is a zombie and has no brain.
- Marty hides the DeLorean in the garage of his future home. (Appears in the novelization)
- Lou's Cafe is Joe's Cafe.
- Marty still attracts attention, but not because of his "life preserver" (down vest). Skinhead comments "Biff-- get a load of his shoes. This dork thinks he's a leprechaun-- he painted 'em green!"
- While Marty wakes from his sleep, he tells Lorraine that he dreamt that the music was awful and there was no rock, the cars were ugly, and his neighborhood hadn't been built yet.
- Doc is having a party at his house and is flanked by attractive women. One of the women offended by his move on her hits him in the head with a beer bottle, giving him his vision.
- Doc suggests fitting a large turbine on the back of the DeLorean and driving off Niagara Falls as well as driving through a nuclear blast.
- Before going into school, Marty assumes the "greaser" style ("I can't believe you actually put this crap in your hair!")
- Marty attempts to bribe George with money instead of following him home.
- While chasing Marty, instead of hitting the manure truck, Biff gets stuck at a railroad crossing with Marty just missing the diesel locomotive.
- Lorraine asks Marty to the dance in the cafe instead of Doc's garage.
- When Marty returns to 1985, the McFly family has a maid, named "Bertha" who asks George, "When will the new house be ready, sir?" (the answer is "as soon as they finish painting the tennis court and re-tiling the swimming pool")
- The Mr. Fusion is known as the "Westinghouse Fusion Energizer".
- Weeze appears, later in the novelization.
- Descriptions for the 1985 versions of George McFly, Lorraine Baines McFly, and Biff Tannen are nearly identical to those shown in the film.
- Ages given include Lorraine at 47, George at 47, Biff at 48, Linda McFly at 19, and Dave McFly at 22.
- The draft notes that the McFly family sit down to eat meat loaf, Kraft macaroni and cheese, Bird's Eye mixed vegetables, and French's instant mashed potatoes.
- Marty was to send his audition tape to B&G Records.
- Marty pulls out a $20 at the cafe to pay for his nickel coffee and Lou won't break a 20.
- When Marty runs into George, he tries to convince him he's his father by slipping that George's birthday was August 18 and that his mother's name was Sylvia.
- The meal at Lorraine's house is identical to the one he ate in 1985.
- A Sir Randolph commercial appears on the television, with a lung doctor smoking after surgery. (Appears in the novelization)
- Doc opens his future self's suitcase and finds a hair dryer. This scene was filmed and is shown on the DVD release.
- Doc adds after showing Marty the photograph that his family is disappearing based on their age, with Dave being the first since he is the oldest.
- Marty watches his mother cheat on a test. This scene was shot but cut from the final film. It appears on the DVD release.
- George claims his father encourages him in his writing. However, in the novelization, his father Arthur McFly is quite the opposite and attempts to talk him out of attending college.
- After Doc is seen by Marty watching the camera footage, he states that he "can't believe it's made in Japan." This dialogue was removed from the film but reappears in Back to the Future Part III.
Behind the scenes
It is known that Eric Stoltz was filmed in the scene where Marty sets off a fire alarm to get out of detention, and that the filming began (with Stoltz) on November 26, 1984, six weeks after the fourth draft of the script was completed. As such, those scenes that were filmed with Stoltz may well be closer to the fourth draft than to the final version of the same scenes with Michael J. Fox. The detention scene still remains in the novelization.
The script can be viewed at the Internet movie script database imsdb.com
The explanation that Doc hired Marty to clean his garage and offer him these things is not accepted by most fans, as it contradicts the characterizations of Marty and Doc we see in the finished film. Co-writers Robert Zemeckis and Bob Gale say they once considered expanding on their relationship, but decided against it, reasoning that children and adolescents are often attracted to eccentric or mysterious neighbors.