Editing Back to the Future (section)

===Conception and writing===
[[File:Robert Zemeckis by David Shankbone.jpg|thumb|left|upright=0.75|alt=Robert Zemeckis|Director [[Robert Zemeckis]] in 2010, who developed ''Back to the Future'' with his long-time friend Bob Gale]]

Long-time collaborators [[Bob Gale]] and [[Robert Zemeckis]] conceived ''Back to the Future'' in 1980.<ref name="BOMGaleInterview" /><ref name="EsquireDidntGetMade" /><ref name="HFPAOralHistory" /> They wanted to develop a film about time travel but struggled to create a satisfying narrative, and were desperate for a successful project after the critical or commercial failures of their recent efforts in collaboration with Zemeckis's mentor, [[Steven Spielberg]].<ref name="BOMGaleInterview" /><ref name="EsquireDidntGetMade" /><ref name="HFPAOralHistory" />

Following the release of their comedy ''[[Used Cars]]'' (1980), Gale visited his parents and came across his father's high school [[yearbook]].<ref name="HFPAOralHistory" /><ref name="NYTimesGaleJul85" /> He wondered if he and his father would have been friends had they attended school together. He did not think so, but realized he could test his theory if he could travel back to a time when he and his parents were a similar age.<ref name="NYTimesGaleJul85" /> He shared the idea with Zemeckis, who recalled his mother's childhood stories were often contradictory.<ref name="HFPAOralHistory" />

Gale and Zemeckis began a draft in late 1980. They sketched and acted out each scene to help develop the dialogue and actions.<ref name="NYTimesGaleJul85" /> They believed many time-travel films focused on the past being immutable and wanted to show the past being altered and the effect those changes would have on the future.<ref name="HFPAOralHistory" /> In the draft, [[Copyright infringement|video pirate]] Professor Brown builds a time machine that sends his young friend Marty back to the 1950s where he interrupts his parents' first meeting.{{sfn|Gaines|2015|p=12}} In September 1980, Gale and Zemeckis pitched their idea to [[Columbia Pictures]] president [[Frank Price]], who had liked ''Used Cars'' and was keen to work with the pair. Gale recalled having to rein in Zemeckis's enthusiastic pitch before Price had time to change his mind.<ref name="EsquireDidntGetMade" /> Gale and Zemeckis completed the first draft for Price on February{{spaces}}21, 1981, but Price believed it needed significant refinement.{{sfn|Gaines|2015|p=12}}

Some early concepts were abandoned. Originally, Marty's actions in 1955 had a more significant impact on the future, making 1985 more futuristic and advanced, but every person who read the script took issue with the idea.<ref name="BOMGaleInterview" /><ref name="TheGuardianHowWeMade" /> Marty's father also became a boxer, a result of his knockout punch on Biff.<ref name="TheGuardianHowWeMade" /> The time machine was a stationary object moved around on the back of a truck.<ref name="ShortlistDudley" /><ref name="TheGuardianHowWeMade" /><ref name="SlashFilmFridge" /> Inspired by the documentary ''[[The Atomic Cafe]]'', the drained time machine was written to be powered by Marty driving it into a nuclear explosion, combined with an additional ingredient: [[Coca-Cola]].{{efn|Attributed to multiple references:<ref name="TheGuardianHowWeMade" /><ref name="SlashFilmFridge" /><ref name="Cryer" /><ref name="ColliderDifferences2020" />}} Gale and Zemeckis took inspiration from tales of legendary scientists, opting to make the time machine's creator an individual instead of a faceless corporation or government.<ref name="BOMGaleInterview" /> The pair wanted the inciting time-travel incident to be an accident so that it would not appear that the hero was seeking personal gain.<ref name="TheGuardianHowWeMade" />

Gale and Zemeckis drew humor from the cultural contrasts between 1955 and 1985, such as Marty entering a 1955 soda shop in 1985 clothing; the  shop owner asks Marty if he is a sailor because his down vest resembles a [[Personal flotation device#Life jacket|life preserver]]. They also identified conveniences of 1985 that Marty had taken for granted, but would be denied in 1955. Gale and Zemeckis struggled with the writing, as they were in their 30s and did not particularly identify with either era.<ref name="NYTimesGaleJul85" /> They were inspired by the [[All-American]] aesthetic of films by [[Frank Capra]] featuring [[Picket fence|white picket fences]] and exaggerated characters similar to Biff,<ref name="ShortList" /> ''[[The Twilight Zone (1959 TV series)|The Twilight Zone]]'', science fiction films, and books by [[Robert Silverberg]] and [[Robert Heinlein]].<ref name="CNNGaleInterview" /> The romantic relationship between 1955 Lorraine and her future son was one of the more difficult writing challenges.<ref name="NYTimesJun1985AttheMovies" /> Gale and Zemeckis attempted to take the concept as far as possible to keep the audience on edge. They believed it had to be Lorraine who stopped the relationship; she remarks that kissing Marty feels like kissing her brother. Gale jokingly said no one asked how she could make that comparison, but that audiences would accept it because they did not want the relationship to happen.<ref name="EsquireDidntGetMade" /> The second draft was completed by April{{spaces}}7, 1981.{{sfn|Gaines|2015|p=12}}