Final answer:
Screenplays incorporate significant visual elements, often represented through italicized stage directions, which complement the dialogue and are essential to the production's impact.
Step-by-step explanation:
Screenplays are a delicate balance of visuals and dialogue. While it’s difficult to quantify exact percentages for such a creative medium, it is often emphasized that a significant portion of the impact of a play or film comes from the visual elements. The way stage directions are formatted in a screenplay, typically italicized and separated from the dialogue, reflects the importance of visual storytelling.
The narrator or a chorus may also be utilized, especially in classical plays, to introduce the scene or set the tone. However, the bulk of the production's effect is driven by both the words the actors say and the visual devices of the production. The screenplay with its stage directions and dialogues are central for guiding a performance to success, emphasizing that a substantial portion of a screenplay is dedicated to visual elements.