Guide · Screenplay
How to adapt a novel into a screenplay
A novel can spend a page inside a character's head; a screenplay can only show what a camera sees and a microphone hears, in about a hundred pages. Adaptation is the work of choosing what carries the story across that gap.
1. Know the story before you touch the scenes
Start by writing down what the book is about in one sentence, who changes and how, and which events cannot be removed without the story collapsing. Everything else — subplots, secondary characters, favourite passages — is negotiable. Adaptations go wrong when the writer starts from chapter one and transcribes forward; they go right when the writer starts from the spine of the story.
- The premise in one sentence: who wants what, and what stands in the way.
- The protagonist's change: who they are on page one and who they are at the end.
- The load-bearing events: the five to eight moments the story depends on.
- The world rules: what is true in this story and must stay true on screen.
2. Fix the canon: characters, names and facts
Long books are full of the same person under different names, titles and disguises, and of facts that are easy to contradict a hundred pages later. Before writing, make one list of characters — with their other names, relationships and what the book actually says about them — and one list of places. That list is the canon: every scene you write has to agree with it.
3. Compress, combine, externalise
A feature screenplay runs roughly 90 to 120 pages, about a minute of screen time per page. Most novels hold several times that much story, so three tools do most of the work:
- Compress: several scenes that make the same point become one.
- Combine: two minor characters with the same function become one person.
- Externalise: what a character thinks becomes something they do, say or decide — or something we see them avoid.
4. Build the structure before the pages
Lay the story out in acts and sequences first: what each sequence is for, which chapters it draws from, and where it turns. This plan is cheap to change and expensive to skip — moving a sequence in an outline takes a minute; moving it in a finished draft takes days. Check the plan against the book: is any load-bearing event missing, merged into another, or placed in the wrong order?
5. Write the scenes — and check them against the book
Write scene by scene from the plan, in standard screenplay format: scene headings, action in the present tense, dialogue that sounds like the characters in the book rather than like summaries of them. Then read the draft against the manuscript. The usual faults are a character acting against what the book established, a name or fact drifting, a scene invented where the book already had a better one, and an ending that resolves something the book left open.
6. Decide what is intentional
Not every difference from the book is a mistake. A good adaptation changes things on purpose — to tighten, to dramatise, to fit a running time. The discipline is to know which changes you made deliberately and why, and to fix the ones you didn't.
Where CAINIX fits
CAINIX follows these same steps with you. It reads the whole manuscript and proposes the story details and the character list (with every other name and disguise linked to the right person) for you to approve; builds the screenplay plan with each sequence tied to its chapters; writes the screenplay from the whole book and that plan; and checks the result against the manuscript, so you decide for each finding whether to fix it or keep it as intentional. The result is yours to edit, in PDF, Word, Fountain or Final Draft.