What is the inciting incident in "To Kill a Mockingbird"?
To Kill a Mockingbird is not necessarily a plot-driven novel, so it is difficult to pinpoint one incident upon which the entire story turns. Is it the mystery of Scout’s neighbor, Boo Radley, and the children's decision to catch a glimpse of him? Is it Jem’s mended pants on the fence, causing the children to amend their opinion of Boo? Is it their first exposure to blind prejudice in Mrs. Dubose? Or the arrest and trial of Tom Robinson, and the news that Atticus is assigned to defend him?
Arguments can be made for all these events and more. Without their interest in and superstitious fear of Boo, Scout and Jem would never have begun the “coming-of-age” journey that characterizes the book. Without their experience with Mrs. Dubose, they would not have learned about snap judgements and showing empathy for others, a lesson they will need later in the story.
But it is Tom Robinson’s trial in Book Two that is the major turning point in the story, the point where all of Scout’s experiences and observations in Book One begin to make sense and have context. The trial brings out the town’s prejudices and racial divides with a clarity that even an eight-year-old Scout cannot fail to notice. It is the trial which leads to Mr. Ewell’s antagonism toward Atticus, and his attempt to harm—or possibly to kill—Scout and Jem on Hallowe’en night. It is Ewell’s attempt on the children's lives which leads to Boo Radley’s timely rescue, and, in the course of events, to Jem’s broken arm.
And in a very neat twist, it can be said that the need to explain how her brother broke his arm that summer is the main reason (possibly the inciting incident?) for Scout telling the entire story in the first place. One of the great things about literary study is that there is sometimes more than one right answer to questions like this one.
The inciting incident is the event without which the conflict and therefore, plot, of the novel would not occur.
Scout claims that "it all started the summer Dill came to us." She says that it was his idea to make Boo Radley come out--and that's what eventually happens at the end of the novel, as a result of the trial and Bob Ewell's reaction to it. The kids are more focused on making Boo Radley come out and that is their "conflict" until the book takes a more serious shift in Part Two.