A treatment is a prose document typically used by screenwriters to sell script ideas. The treatment can work for a novel as well. While there are no set rules on the length of a treatment or how it is formatted, an effective treatment will always summarize the story it represents and include key plot points, dialogue and anything else that can help sell the story. Whether you're writing a treatment to keep your writing focused or using it to sell your novel, a well-written treatment can be an effective starting point for any novelist.
Write a synopsis at the beginning of your treatment. A synopsis encapsulates the essential elements of the story without going into details. It's an overview of the story. While the synopsis isn't a necessary part of the treatment, it can be helpful to anyone who will read your treatment. Think of the synopsis as the description found on the back of a book. Two or three paragraphs is more than enough for the novel synopsis.
Indicate chapters in your treatment. Capitalize and bold chapter headings, then write the events of the chapter as they unfold. Write in third person. Present tense is preferred in treatments, although writing in past tense (as many novels are written) is acceptable. Present tense is preferred because it puts the reader (possibly a buyer or publisher) in the moment.
Write only essential dialogue. The goal of the treatment is to lay the story out as it will happen in the novel, highlighting all the major plot points and twists. Dialogue should only be included if it is something that is key to the story. If it becomes necessary to use dialogue, avoid standard quote presentation. An example of how to present information a character imparts might be: Jackie tells Sam that she knows who murdered their parents.
Flesh out all of the plot details in your treatment. Don't keep secrets in your treatment. This includes surprise endings. In the novel, a killer may not be known until the end of the book. In the treatment, you will want to give this information, as well as any other information crucial to understanding the plot. You can add parenthetical notes as you write to help clarify scenes.