As a writer, you need to learn to temper your expectations and avoid thinking too many steps down the road. If you’re already thinking about the awards your work will garner then you’re bound to overlook its flaws and make grave errors. Casting your screenplay before you actually write your dialogue may seem like putting the cart before the horse but it could actually help your writing.
You may think that casting your story with actors in mind before you start writing will limit your creativity. The logic follows that if the character is already someone else in your head that you’ll be hesitant to let that character change or evolve. In reality, as long as you cast an actor that you think is malleable, it can help ground your characters in reality.
When characters only appear in your mind as abstract concepts, they lack the depth and truth of a real person. Casting an actor in that role can breathe life into the words and help you picture what they would look like actually saying them. You’ll be able to answer the all-important question “would this character say that?” Casting the appropriate actor in each role will help define that character and enrich his or her voice.
Casting your characters before you write can also be helpful when you have scenes with multiple characters. When you write a scene, it’s natural to write all of the dialogue in your own voice. After all, it’s you that’s thinking the words into existence, so they sound the same as your genuine thoughts in your head. That does a disservice to the characters and your audience. If you have two actors in mind for each of the characters, you’ll see the scene in your head and watch them talk to each other with your words. In essence, you’ll hear those same words coming out of the actor’s voices, rather than your own. You might find that your actors (even in your mind) have different cadences or speech patterns that will make your dialogue sharper and more nuanced.