Character Development, Story, Technique

Act I – Setup: Three-Act Structure In Screenwriting

This article is part of a series on using the three-act-structure for writing screenplays. After a brief overview of the model of the three acts, this first installment will deal with the setup of your story in the first act.

What Is The Three-Act-Structure?

The three-act-structure is a model that goes all the way back to Aristotle’s dramatic theory as outlined in his work Poetics. In modern times, screenwriting lecturer Syd Field published extensively on the three-act-structure and established it as a paradigm. So what is it?

This narrative model divides the plot of a movie into three sections, which are also called setup or exposition, confrontation, and resolution. They represent the rise and fall of the action and each act is initiated by a preceding plot point. Although there are minor ups and downs or twists during each act, only the plot points turn the story into a completely new direction.

The three acts also place other dynamic incidents throughout the story that are crucial for the development of plot and character, such as the call to action, a false defeat or victory, and the climax.

Why Use The Model Of The Three-Act-Structure For Screenwriting?

You only want to write one story at a time, so it might seem counterintuitive to break your screenplay into three acts. Yet the most important takeaway from Aristotle’s theory is that the three sections are more than just the beginning, middle, and end. It’s fundamental that you connect them to form a unified whole in which each action follows the principle of causality.

The three-act-structure is there to help you place scenes at the exact right moment in order to string your narrative together in a plausible and logical way to create a compelling story with an optimum of suspense and tension thanks to well-spaced twists, turns, and plot points.

Act I sets the stage for the audience with a time and place and an introduction to the most important characters, notably the hero.

The Setup: Writing The First Act Of Your Screenplay

What To Include In Act I

In order to introduce the audience to your story and set up the action in the acts to come, the first act should feature the following:

  • Hero: The protagonist deserves special attention, so you show them in their regular circumstances which they are about to leave. 
  • Setup: This is the who, where and when of your story – an introduction of the main and secondary characters and their world.
  • Theme: An allusion to the transformation your protagonist will undergo, a hint of what the movie is really about.
  • Call To Action: This inciting incident is the catalyst that will send your hero off into the unknown.
  • Resistance: Your main character shows some reluctance to accept the call and go on their journey.

Act I sets the stage for the audience with a time and place and an introduction to the most important characters, notably the hero. The action starts with an incident that confronts the hero with an external problem, which is often connected to an internal problem the hero faces as well. The first act, therefore, poses the dramatic question: how can the hero solve these problems? The premise of your story is that after Act III, the audience will know the answer.

Opening Image: Painting The Blank Canvas Of The Mind

At the beginning of a movie, the audience’s mind is open as they haven’t yet formed a frame for the story. You can still literally paint anything on this blank canvas and they will accept it. We call this suspension of disbelief. Events of pure luck or chance seem much more plausible in the first than in the second act. Screenwriters know this, yet struggle with it because they think they have to come up with a fantastic hook, an early, exciting scene to grab the audience.

James Bond or Indiana Jones films start this way, but that’s because stunts or chases are par for the course for these heroes. Let your opening image show your hero in their world. Provide a snapshot of their ordinary, everyday life. Ordinary doesn’t mean boring: If your hero hunts space aliens for a living, then you show that.

Hook and opening images don’t have to be the same. You can tease the action and turmoil about to come over your main character, then introduce them in their normal circumstances. At the same time, you can set the mood and tone of the movie with humor or suspense, drama or action, mystery or horror.


It’s important that the audience understands and gets to know your main character before their major change. What kind of person is your hero, with what advantages and flaws? Show the goal your character wants or is pursuing. Any characters that are important in the beginning and for this phase of your main character also need to come into play. To create dynamics between them, the hero usually faces a problem or character flaw, or even more than one. Here, you are setting up the different world of the second act. The audience needs to see that things cannot stay the same for your protagonist. If nothing changes, they will never attain their goal. In screenwriting terms, this is called stasis equals death (literal or figurative).


Your first act plants the seed for what will grow into the theme of your story. Your hero wants one thing but needs another, something that differs from their goal and is universal. By the end of the movie, they will be more independent or responsible, less fearful or selfish, or have found love, faith, forgiveness, trust, or acceptance. It’s up to you to equip your main character with a need that creates a fitting theme for your story. The theme is commonly introduced through a secondary character or thing, not your protagonist. It can be something they see or a line in dialog with someone else.

Call To Action

Once you’ve introduced your hero with their goal and theme and shown them in their surroundings, it’s time for the call to action. This inciting incident is the catalyst that sets everything in motion. It needs to break the status quo of your main character and prevent them from going back to normal afterward. This event is an action that happens to the hero; they don’t cause it. In traditional drama, the call to action often comes in the form of bad news. It’s up to you to show something big on screen that your hero will have to face.

Resistance: Should I Stay Or Should I Go?

No character accepts a life-changing event just like that, and neither should your protagonist. They assess the incident and consider their chances, but they are reluctant to go. So either they debate back and forth if they should really go, or the call has to be repeated a second time to make them embark on their journey. Their old life could literally be in shambles, or their peers cast them out. To show the reluctance of your hero, you can again place them in their usual surroundings so the audience will see how the inciting incident affects every aspect of their life. Depending on your story and main character, you can replace the phase of reluctance with one of preparation. Your hero is not yet ready to leave, so they must gather tools or learn skills before they can go.

Act I Checklist

Do you think your first act has everything it needs to create a compelling beginning for your story? Check your screenwriting with these points:

  • Hero

Show your hero in their everyday surroundings.

Do you have an opening image and/or hook?

Is there a hint at how your main character will change?

  • Setup

You’ve introduced the secondary character(s).

The audience knows the main character’s goal.

You’ve shown your hero’s problem or flaw.

  • Theme

The theme relates to what your hero will learn or how they will change at the end.

A character or thing introduces the theme, not your protagonist.

  • Call To Action

The inciting incident happens to the main character in an action scene.

The call to action makes it impossible for your hero to return to normal.

The status quo is broken.

  • Reluctance

Your hero ponders a (dramatic) question, i.e. should I stay or go?

If your protagonist needs to prepare, what for and why?

Your hero is reluctant to follow the call and you show how that affects their life.

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Jakob Straub

Jakob is a freelance writer and storyteller. He publishes creative fiction in English and German and assists other writers with the development of plot and characters to shape their manuscripts into compelling stories. So far, Jakob hasn't sold his soul for a screenwriting deal, but he'll consider all offers.