In the firstBack to the Futuremovie, Marty McFly encounters many hurdles throughout his time-traveling adventure in 1955 Hill Valley, including repairing Doc Brown’s DeLorean, fighting Biff and his friends, and ensuring his parents fall in love at the “Enchantment Under the Sea” dance while jamming out to Chuck Berry. However, one thing that’s absent from the 1985 film isMarty’s aversion to the word “chicken,” an iconic plot point introduced inBack to the Future Part IIthat would come to define Marty’s entire character in the future.
Despite only coming into play nearly halfway through the trilogy,Marty’s refusal to back down to “chicken” became a defining characteristicof the denim-clad skateboarder, whosesignature line “Nobody calls me chicken” becomes one ofthe staples of theBack to the Futureseries that appears in (almost) every film. While the first film largely focused on Marty’s efforts to get back to 1985, theBack to the Futuresequels needed to introduce new conflict within Marty’s psyche, andwhat better place to start than with the prideful adolescent’s insecurities and ego?

Back To The Future Part II Introduced “Chicken” Because Marty McFly Needed A Character Flaw
The First Film Focused On George’s Character Arc, Not Marty’s
Per a CinemaBlend interview with screenwriter Bob Gale, the idea for “chicken” came from the desire to give Marty a character flaw for him to overcome in theBack to the Futuresequels.Since Marty is shown to be easily provoked in the first film, it wasn’t a large jump for the screenwriters to then “verbalize” his explosive nature, according to Gale:
Well, when it came time for us to do the sequels, we realized that we needed to give Marty a character flaw that he was going to have to correct. And we didn’t really establish a real character flaw in the first movie because the character who experiences growth in the first movie is George McFly. But we did establish Marty’s a bit of a hothead, and that it seems like he’s kind of quick to mix it up with Biff in the scene in the school cafeteria and the scene in the café when Biff just kind of towers over him. So we thought, ‘You know what? Let’s use that.
This allowed Gale and director Robert Zemeckis to set up a fatal flaw for Marty, which ultimately leads him toget into a disastrous car accident that ruins his music career dreamsafter Needles goads him into a dangerous drag race—that is, until he successfully overcomes his pride inBack to the Future Part IIIand resists taking the bait when Needles calls him “chicken.”
In short, since the firstBack to the Futurefocused so much on George McFly’s arc, the sequels had to set up Marty’s fatal pitfallin order for the time-traveling teen to resolve his emotional arcat the end of the trilogy.
Back To The Future’s “Chicken” Line Is Different From Other Running Gags In The Series
Marty Has Real Character Development In Part II And III
What makes the “chicken” line different from the rest of the recurring gags in theBack to the Futureseries is that it wasn’t included from the start. The rest of the callbacks—including Marty always waking up to a version of Lorraine (Lea Thompson), Doc Brown’s “Great Scott!” catchphrase, and Biff always ending up in manure—were all set up in the first film, and their inclusion in the following sequels set up the franchise’s theme of events repeating themselves throughout history.
Despite being added late in the series, the “Don’t call me chicken” line has become nearly as iconic as the rest of the recurring gags in theBack to the Futureseries, namely because it’s always fun to root for a flawed hero as he navigates overcoming his fatal weakness. Furthermore, the “chicken” line ismuch more than just a running joke in the trilogy—it’s true character development, and by resisting the urge to fall into the same old trap, Marty completes his emotional arc at the end of the third film.