Act I comprises the first quarter of the screenplay. (For a two hour movie, Act I would last approximately 30 minutes.)
What happens in Act I (Setup):
- Exposition: The part of a story that introduces the characters, shows some of their interrelationships, and places them within a time and place. This part of the story introduces the main character, the dramatic premise, and the dramatic situation.
- Main character: the person in the story who has a need/objective to fulfill and whose actions drive the story
- Dramatic premise: what the story's about
- Dramatic situation: the circumstances surrounding the action
- Inciting Incident: an event that sets the plot of the film in motion. It occurs approximately halfway through the first act.
Act II comprises the next two quarters of the film. (For a two hour movie, Act II would last approximately 60 minutes.)
What happens in Act II (Confrontation):
- Obstacles: In the second act, the main character encounters obstacle after obstacle that prevent him from achieving his dramatic need.
- First Culmination: a point just before the halfway point of the film where the main character seems close to achieving his or her goal/objective. Then, everything falls apart, leading to the midpoint.
- Midpoint: a point approximately halfway through the film where the main character reaches his/her lowest point and seems farthest from fulfilling the dramatic need or objective.
Act III comprises the final quarter of the film. (For a two hour movie, Act III would be the final 30 minutes.)
What happens in Act III (Resolution):
- Climax (Second Culmination): The point at which the plot reaches its maximum tension and the forces in opposition confront each other at a peak of physical or emotional action.
- Denouement: The brief period of calm at the end of a film where a state of equilibrium returns.
Source: Three-act Structure