The “But and Therefore Rule” of screenwriting from South Park creators Matt Stone and Trey Parker
Compiled by Martin Brossman for his small business training in video, storytelling, and YouTube marketing programs.

The “But and Therefore Rule” of screenwriting, developed by South Park creators Matt Stone and Trey Parker, is a technique used to enhance narrative structure and ensure story progression is driven by causality. Instead of using “and then” to connect events, the rule encourages the use of “but” and “therefore” to link story beats, creating a more engaging and dynamic narrative.

Key Points of the “But and Therefore Rule”:

1. Replace “and then” with “but” or “therefore”:
   • Instead of connecting events with “and then,” which can lead to a disjointed and monotonous story, use “but” or “therefore” to introduce conflict and causation.
   • Example:
     • “Jimmy went to the mall, and then he realized he was tired. And then he picked up a coffee. And then he parked in an illegal spot because he was tired.”
     • Revised: “Jimmy went to the mall, but realized he was tired when he stepped inside. Therefore, he picked up a coffee. But since he was tired, he parked in an illegal spot.”
2. Ensure causation between each story beat:
   • Each event in the story should lead logically to the next, driven by the characters’ actions and the situations they encounter.
   • This creates a chain reaction where every scene has a clear cause and effect, maintaining the audience’s interest and investment in the story.
3. Apply to every scene:
   • Every scene should have a clear purpose and function as a standalone piece of the story, contributing to the overall narrative.
   • This approach helps to avoid passive storytelling and keeps the plot lively and engaging.
4. Create tension and momentum:
   • By introducing obstacles (using “but”) and consequences (using “therefore”), the story maintains a sense of urgency and direction.
   • This technique helps to build a compelling and cohesive narrative structure.

Examples in Practice:

• Simple Example:
  • “James goes out for a run, and then it rains, and then he goes swimming, and his ex-girlfriend is there, and then he goes home.”
  • Revised: “James goes out for a run, but it is raining; therefore, he goes swimming. But his ex-girlfriend is at the swimming pool, therefore he hurries home.”
• Famous Literature:
  • In “Romeo and Juliet”:
    • “Romeo and Juliet fall in love, but their families are rivals, therefore they cannot be together.”
  • In “Harry Potter and the Philosopher’s Stone”:
    • “Harry discovers he is a wizard and goes to Hogwarts, but then learns Voldemort is after him, therefore he must find a way to defeat him.”

The “But and Therefore Rule” is a powerful tool for screenwriters to ensure their stories are engaging, logically coherent, and full of momentum. By focusing on causality and the natural progression of events, writers can create narratives that captivate and maintain the audience’s interest.

See the original video of Matt Stone and Trey Parker explaining the process: