Answer: Eric Stoltz

Many times when you hear movie trivia, you hear about how so-and-so was considered for, but never actually hired, to play a role. For example, Will Smith was considered for the role of Neo in the 1999 sci-fi film The Matrix, but never actually participated in the production of the film.

In the case of Marty McFly in the 1985 sci-fi comedy Back to the Future, however, Eric Stoltz was not only originally cast for the role, but actually participated in the first four weeks of filming it.

Director Robert Zemeckis had wanted to cast Michael J. Fox in the role, but the actor was tied up with the TV show Family Ties. The show’s producer, Gary David Goldberg, was insistent that Fox was essential to the show’s success and couldn’t miss any set time, especially with Fox’s co-star Meredith Baxter off on maternity leave. Zemeckis went with Eric Stoltz, one of his second choices, and filming began.

Zemeckis quickly realized that Stoltz was a poor fit for the role. It wasn’t due to poor acting, however, but was a matter of “intensity”. Stoltz approached the role in a very serious and dramatic fashion, whereas Zemeckis had envisioned the role as more comedic and an extension of Michael J. Fox’s natural personality. Scrapping the first four weeks and recasting the newly-available Fox added 3 million dollars to the production budget, but despite this steep cost, they went ahead with the change.

The replacement of Stoltz with Fox isn’t the only casting shuffle that occurred. During original casting, John Lithgow was cast as Doc Brown, but was replaced with Christopher Lloyd due to scheduling conflicts. The iconic pairing of Fox and Lloyd could have, instead, gone down in history as Stoltz and Lithgow.