Non-linear films like Pulp Fiction, Reservoir Dogs, Annie Hall, and Dunkirk tell stories by jumping backward, forwards, and sideways in time to tell a single story. Such stories are not presented in chronological order, or the narrative does not follow the direct causality pattern of the story events that you’d find in a three-act structure or through the average fabula—the meat of the story.
The concept behind non-linear films is to challenge the way we think we remember things—or how characters recall their own memories of experiences they’ve been through.
Memento is often attributed to a non-linear screenplay structure but is actually differentiated by working in reverse chronological order. However, that reverse chronological order in the screenplay can still be perceived as a linear narrative. Non-linear stories go back and forth and sometimes sideways. We’re not going from Point A to Z or from Point Z to A hitting every point in between. Instead, we’re maybe going from Point A to Point D, then jumping to Point L and Point M, only to jump back to Point B and Point C.
This challenges the reader and the eventual audience. They have to remember where certain scenes and storylines left off and they have to be able to pick the story back up almost immediately.