Is it possible for the Inciting Incident to happen in backstory?
Technically, ‘backstory’ is not in the movie. It is the history of your characters before the time the story starts. Because we need to see the Inciting Incident and how it affects the protagonist, it cannot happen in the backstory.
However, the inciting incident can happen ‘in the past’, as long as we see it.
Let’s look at Sweeney Todd. The barber’s wife was taken by the judge in the past. Because we see it in a very brief flashback shot, I guess you could still call this backstory. Todd returns to London and the Inciting Incident occurs when he learns the details from Mrs. Lovett about what happened to his wife and daughter .
As a result, he plans on taking revenge (end Act One).
Let’s assume a different order for a moment: say the exact details of how the judge destroyed the barber’s wife had been known by Todd at the time he was deported (Inciting Incident). He could still only take revenge after returning many years later. It could have worked, but it wouldn’t have been so strong, I think.
The Inciting Incident in the film really happens ‘in the now’, where it should be.