The WGA's decision to give Whedon a "screenplay by" credit indicates his substantial contribution is equal to at least 33% of the final product.

After an unspeakable family loss, Zack Snyder left “Justice League” in May and handed the film over to Joss Whedon to complete. However, Whedon was already been working with Snyder to write new material for additional photography. That Whedon was already taking his cues from Snyder in reshaping the film — to say nothing of the “Avengers” credit on his resume — made him the obvious choice to direct the reshoots and steer the film over the finish line.

Since then, “Justice League” producers, cast, and crew have been in lock-step in their message: Whedon selflessly came aboard to carry out Snyder’s vision. Wonder Woman herself chimed in: “This is Zack Snyder’s movie,” said Gal Gadot in an interview with Empire Magazine. “Joss only did a few weeks of reshoots. He was Zack’s guy and knew exactly what he wanted to get.”

This week, producer Charles Roven went so far as to put a number on Whedon’s contribution, saying 80-85 percent of the final film belonged to Snyder’s shoots, adding, “There’s only so much you can do with the other 15, 20 percent of the movie.”

Considering the years Snyder and his wife, producer Deborah Snyder, spent shaping the extended DC Universe leading up to “Justice League” and its subsequent chapters, it’s easy to understand — especially under the tragic circumstances of their daughter’s death that prevented the Snyders from finishing the job — why the DCEU team defends what Gadot called “Snyder’s beautiful vision.”

Clay Enos

Yet critics tell a different story, focusing on what they say is a noticeable tonal clash of two distinct filmmakers whose voices are as different as “Buffy the Vampire Slayer” and “300.” What’s more, Whedon’s light touch is noticeable throughout the film, on which he spent months between rewrites, two months of reshoots, and reshaping the film in post production.

In this case, Whedon’s writing credit reveals more than Snyder’s sole directing credit. That’s because the Directors Guild contract with the studios is clear cut: There can only be one director on a feature film (Directing partnerships like Joel and Ethan Coen are seen as one directing entity). The DGA also maintains the right to step in to decide who gets that directing credit at any point on any film. In this case, there’s little reason to believe the guild interceded on “Justice League”: Snyder’s role as the director was never questioned, nor, as IndieWire has learned, did Whedon at any point request writing or directing credit for “Justice League.”

However, the story of Whedon’s “screenplay by” credit is far more revealing. The procedure for splitting up writing credit is necessarily more involved, with clearly outlined standards. This is especially true of “Justice League,” as sources close to the process tell IndieWire that it was the Writer’s Guild that determined the film’s writing credits. The WGA’s involvement is not unusual, as any writer on a film can challenge the tentative writing credits proposed by the studio. Or, as is likely the case with “Justice League,” an automatic arbitration is triggered when producing entities receive story or writing credit. (It’s automatic because the guild assumes writers don’t feel comfortable challenging their bosses.)

In the case of “Justice League,” which is not based on original material, for Whedon to receive screenplay credit the WGA would need to have determined his contribution to equal at least 33% of the final shooting script.

Putting a numerical value on a writers’ contribution is much more than counting words. Three WGA writers act as arbiters, reading the various drafts without knowing their authors, and compare each individual’s contrition to the final shooting script. Measurement can be subjective, but the WGA identifies four categories in which a second writer’s work can be measured as a substantial contribution: overall structure, new scenes, character and character relationships, and dialogue.

There is also this piece of guidance from WGA to arbiters:

As a general rule, for a “second writer(s)” to share screenplay credit the contribution to the screenplay must consist of changes of a substantial and original nature that, in the opinion of the Arbitration Committee, go to the root of the drama or comedy and constitute substantially more than the contribution of the “first writer.”

In other words, WGA saw Whedon as having made “changes of a substantial and original nature” that they deemed to be at least 33% of the script. In talking to other WGA members for this article, the key phrase they highlight as the north star for arbiters is changes that “go to the root of the drama.”

So let Roven, Gadot, and the other DCEU true believers say what they will. For two months, Whedon directed what he wrote, and then helmed the changes made in the editing room for the last six months. According to the WGA, Zack Snyder’s movie contained a lot more than 20 percent Whedon.

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