Roth has spent sixty years adapting other people's material. Forrest Gump (novel). Benjamin Button (short story). Munich (history). Killers of the Flower Moon (nonfiction). He has a saying about it: bad books make good movies. That's that's the slogan. Or bad plays make better movies.1
The throwaway line carries a real craft principle. Adaptation is not translation. A good book usually does its work too completely on the page to leave the screenwriter room to add. A bad book — meaning a book with a strong premise but uneven execution — leaves gaps the screenwriter fills. Roth's adaptations end up 60 to 70% original despite being labeled adaptations.2 The premise stays. The structure shifts. The dialogue is mostly invented. The characters are deepened or restructured. The film becomes something the source seeded but didn't determine.
Adaptation-as-60-percent-original is the honest accounting of what screenwriting adaptation actually is. The screenwriter is sometimes called a translator. They are usually a co-author of a different work that shares premise and characters with the source. The novel's interior consciousness becomes scenes. The novel's pacing becomes structure. The novel's themes become the spine. The novel's specific scenes are mostly invented anew.
Faithful adaptation usually fails. The Forrest Gump novel's Forrest weighs 400 pounds3 — Roth cut that, made him slim, changed the tone of the character. Being an idiot is no box of chocolates becomes life is like a box of chocolates. Roth made the changes because faithful translation would have produced a worse film. The principle isn't betrayal; it's adaptation-as-craft.
Three things drive the 60% original portion:
Form difference. Novel interior monologue can't be filmed. Scenes have to be invented to externalize what the novel told internally.
Pacing difference. Novels can spend chapters on what films can spend two minutes on. Whole subplots get compressed, transposed, or invented.
Audience difference. Novel readers commit to a sustained experience. Film viewers commit to two hours. Material that works for one fails for the other and has to be reshaped.
Adaptation-as-60-percent-original gives Roth's other craft principles room to operate. Theme-as-rudder can dominate adaptations because the source's theme can be made more explicit. Find-a-home opening can be redesigned for film. Dialogue economy can replace novel exposition. The 60% original is where the screenwriter's craft lives.
The novel's Forrest weighs 400 pounds, is more savvy, and the tone is more satirical. Roth's adaptation makes Forrest slim, slow, sincere. The change inverts the novel's affective register. The result is a film that's more emotionally available than the novel — a different work entirely while preserving the premise (a simple man traverses 20th-century American history).
Roth also added the bench framing. The novel doesn't have Forrest sitting at a bus stop telling his life story to strangers. Roth invented the framing because the film needed a structural device the novel didn't provide. Pure invention. Foundational to what the film became.
You're adapting source material. Read the source three times. Make a list. Column one: what's load-bearing about this material that must stay. Column two: what works on the page but won't work on screen. Column three: what's missing that the film will need to invent.
Now write the screenplay from column one and column three. Column two is the source's success that you're discarding. Don't apologize for the discarding. The film is a different work.
You'll know adaptation has gone wrong when the resulting script reads as the book with parts cut out. The cut version is shorter but not better. The discipline is to replace what's cut with film-native invention. Subtraction without invention produces thin adaptations.
MacCulloch's discipline of fidelity-to-historical-record sits opposite Roth's 60% original. The historian who took Roth's adaptation approach would be a fictionalizer. The screenwriter who took MacCulloch's approach would produce stage-readings, not films. Different forms, different fidelity requirements.
The compound insight: adaptation, narrative nonfiction, and historical fiction are all constrained-invention forms. The constraint is what gives the invention shape. Pure invention has no shape; pure faithfulness has no breath. The polymath read: most powerful writing operates in the constrained-invention zone, and the writer's craft is the calibration of how much constraint to honor against how much to invent.
The Sharpest Implication
If you're working on an adaptation and feeling guilty about how much you're changing, the diagnosis is that you've internalized a wrong model of what adaptation is. Adaptation is co-authorship. The 60% original is the work the form requires of you. The guilt is the symptom; the craft is the cure.
Generative Questions