When you are preparing to write a screenplay or even preparing to do a major rewrite, it is very helpful to create a blueprint or treatment of what you are going to write prior to actually writing or rewriting it. This is what a treatment is used for. It will help you layout the direction of the entire screenplay and work out some of the kinks before jumping into the whole thing.
Think of it as being an in-depth synopsis of your story. As you can imagine, it is much easier to edit and make changes to a story that is under 10 pages than it is to make changes on a 100+ page script.
If you work out all the story issues, character arc, and theme aspects in the treatment, it will save you an enormous amount of work when you write the screenplay itself.
It has no dialogue whatsoever how a professional screenwriter outlines. (Okay, you can put one or two great lines of dialogue in if you must, but only to show the flavor of the character.) But don’t spend much time on the dialogue in the treatment as you might end up throwing out any given scene before you finalize the treatment, and then you will have wasted time on the dialogue.
When you read it, you should connect with the story emotionally. If it doesn’t affect you emotionally, then you should keep working on capturing the emotion in the treatment before you go on to writing the screenplay. If you can’t capture it in the treatment, you definitely won’t capture it in the screenplay itself, because it already shows that something is missing.
Once you have the whole story fleshed out with the plot, character arc, and theme all working together, and emotionally you are moved deeply when you read it, then you are ready to The only caveat about that is that I recommend that you have a professional review the treatment before you go on and write it, simply because they may respond to it differently.
But for sure, you should work your story out in the treatment first. Oftentimes, when I critique a script and it needs a fair amount of work, I will recommend the writer go back to the treatment stage and rework it before rewriting the script itself. This have proven to be very beneficial.
If you likened the treatment to building a house, you could think of it as being like a full-color sketch of the interior of the house. It would be a sketch of the colors of the living room and the curtains, the couches and pillows. It would have all the mood that the final one would have, but it would nevertheless be only a sketch of it. You could also think of the treatment as a miniature or scale model of the screenplay.