A good screenplay does not advance by luck. A screenplay advances because one thing leads to another, creating a sequence of actions, reactions, and consequences. Dramatic causality is a term for describing this cause and effect pattern and one of the most crucial principles of good screenwriting. Once you master this principle, your story will become logical, gripping, and emotionally satisfying.

First, the screenplay requires an inciting incident. Inciting incident is an event which disrupts the protagonist's routine life and sets off the story events. Without an inciting incident, the plot has no reason to start. For instance, the quiet student who sees the crime is what initiates all other events in the story. An inciting incident provides a conflict, a problem, or a desire to the protagonist.

Another element of the plot is the character’s objective. As soon as the story starts unfolding, there should be a goal that the central character wants to accomplish. This goal provides a certain direction for the character and drives the plot development. The absence of an objective can lead to lack of direction in the screenplay. With a clear goal, the character makes decisions, which generate new events.

The third tool is conflict. The conflict is something that hinders the character’s achievement of his or her objective. The obstacle can be a person, society, nature, and even fear. It is necessary because the conflict transforms events into dramatic actions. With each obstacle, the character has to act in response and face new challenges. With increasing conflict, the causality chain strengthens, as each action generates consequences.

 Fourthly, the element of stakes and consequences plays an important part in creating a good screenplay. Stakes help people understand what might be achieved in case of success or what can be lost in case of failure. Important consequences will make the screenplay interesting. Something serious must happen if the protagonist fails. He may lose his love, freedom, family, or self respect. Every scene in the story is connected through consequences of decisions and actions taken.

Reversal and revelation are the fifth elements of screenplays that make the story unpredictable and exciting. They can come from either discovering some facts or happening to something unexpected. These events help develop the plot and keep people interested. A revelation makes the protagonist see things differently; a reversal creates additional tension and makes a new problem appear.

In conclusion, dramatic cause and effect are crucial to moving a screenplay forward. An inciting incident initiates the action, an objective provides a goal to move the story toward, conflict generates conflict, stakes create consequences, and a reversal or revelation brings surprise. With these five elements combined, a writer can construct a screenplay that makes sense, is interesting, and works on an emotional level. A good screenplay does not consist of just a bunch of scenes; it consists of well connected actions that lead one to another.