A guide for the author, the writers (human or model) and anyone judging a cut. Written 2026-09-20 from published advice by working trailer editors (sources at the end) and from what we learned making two Memory Road trailers. The writers' brief (TRAILER_BRIEF.md section 11a) is the enforceable short form of this; this file is the reasoning.
A trailer is an advertisement for a story, not a summary of it. Its single job is to make a stranger want the rest. Filmmaker Magazine's trailer editor puts it as selling "promise and possibility", and gives the rule that follows from it:
"Never resolve anything! Whenever possible, leave questions unanswered."
A film trailer is cut from the film: real scenes, real lines, reordered and compressed. A book has no footage, so we film the scenes first - but the discipline is the same. The trailer shows moments that exist in the book, in the words the author wrote, arranged to raise a question the viewer can only answer by reading it.
The measure of success is not "did every shot work". Our second trailer passed that test and was dull. The measure is: could someone who has never heard of this book say, after one viewing, who it is about, what is wrong, what he wants, who is against him - and do they want to know what happens?
Everything below comes from this. The viewer has not read the book, does not know a name, and will watch once. After our second trailer the owner - who knows the book - still asked: who are the two people on the sofa? who is "they"? why would they sell his car? does he have a memory problem? why is a policeman on the ground? how did a passing car become a man in a trunk?
Each of those is a fact the writer knew and the screen never said.
Editors describe three acts; Derek Lieu's four-part version is the more useful because it separates the hook from the setup.
| part | share of the running time | what it must do |
|---|---|---|
| 1. Cold open | first 10-15 s | "Hit the ground running with some very exciting, humorous or dramatic scene that requires very little context." One or two shots. The book's best small moment - funny, tender or alarming. Not chapter one. |
| 2. Introduction | to about 35-40 s | The premise. By the end of it the viewer can answer who is this, what is wrong, what does he want. Slowest cutting of the trailer; shots breathe. |
| 3. Escalation | the middle | "Where the antagonist or central problem is introduced, and we get an idea of what the main characters are going to do about it." The opposition gets a face and a reason. Cutting gets quicker. |
| 4. Climax | last 20-30 s | "The music swells, the most interesting shots get cut in rapid succession." Short wordless shots, each shorter than the last (2.5 s, 2 s, 1.5 s...). Then a stop, a last line or image - the button - and the title. |
Energy should rise and fall, not sit at one level: an early quiet moment makes the later noise louder. The strongest single device in trailer sound is the stop: everything cuts to silence for half a second before the final hit or the title.
Length. A full trailer is 1:30-2:30; a teaser is about a minute. For a book, shorter is safer: 75-100 seconds. Ours ran 2:02 with nineteen shots of nearly equal length, which is a slideshow's rhythm, not a trailer's.
Measured on our second trailer: of 14 spoken lines, 3 were in the manuscript, 3 paraphrased it, 8 were invented by the script model. The three that landed were the author's - "Does that mean you're not trying to pick me up?" is funnier and truer than anything written for the occasion.
So: a line spoken on camera is found in the manuscript and used as written - whole or trimmed, never reworded into something the character did not say. The site checks every on-camera line against the manuscript and marks each line on the page: your words, from the book / close to the book / written for the trailer.
Trailer editors sort sound bites into three kinds (Lieu):
A good trailer line works with no context. If it needs the previous page to make sense, it is the wrong line.
"Narration handles complex exposition efficiently, allowing audiences to absorb context while watching related visuals."
Narration and title cards interrupt the picture, so editors use them sparingly - but a book trailer has more to explain than a film trailer and no famous faces to lean on. Use one narrator, one voice, three to five lines, each laid over pictures that show what it says:
The narrator is not the hero thinking aloud, and must say only what the book establishes. It is the voice telling a stranger why this story matters.
Three or four words, on screen about a second, at most three of them before the viewer loses the thread. Good for time, place and the one fact a picture cannot carry: FORT LAUDERDALE, 2016. HE KNOWS TOO MUCH. And the last card is the title, after the stop.
A trailer may skip time. It may not skip the reason. If one shot ends with a deputy shining a torch in a man's face and the next begins with the deputy on the ground, the viewer needs the cause - shown, said, or bridged by the narrator ("He had not meant to hurt anyone."). The same for a car pulling up and a man found in a trunk: show the hands, the door, the dark - or say it.
Editors also pair sound to picture noun by noun: "Trailer editors will usually latch onto any noun in a line of dialogue, and try to find an image that will go with it." If the narrator says road, we are looking at the road.
Music "literally sets the tone and the rhythm"; most trailers use up to three cues, one per act. We do not yet lay music - it is the largest remaining gap - but the cut should be planned for it: a quiet bed under the introduction, a pulse through the escalation, rises into hits in the climax, then the stop. One well-placed hit is powerful; "four is a parody".
| craft rule | how we do it |
|---|---|
| On-camera lines from the book | checker objects to an on-camera line not in the manuscript; page badges every line |
| Narrator | a cast member with a voice and no appearance; all lines lip_sync: false |
| Shots run their written length, line placed within | stretched Action/Cut slate, say_at start / middle / end |
| Accelerating climax | wordless shots may be as short as 1.5 s in the edit (each still costs a 5 s generation) |
| One action too big for one take | split into two shots (the abduction became 17 and 17a) |
| Objects and cars stay the same | tracked props with reference pictures |
| The camera can actually see it | line-of-sight rule (no urn "seen" from the back seat) |
| Nothing bought twice | request-hash guard on pictures, clips and audio |
The video model films one shot from one opening picture and one description, with no memory of the shot before. Everything that carries across a cut has to be put in front of it twice.
The rule: a shot that continues the last one starts on the last one's last frame, and its first sentence says what is done about whatever was left moving.
| carries across the cut | how to hold it |
|---|---|
| the moving object (ball, phone, cup, door) | last-frame opening + a "go get" sentence; where it is in feet from a fixed thing |
| which way people face | say it - "facing the basket", "her back to camera" |
| who is where | name each person's spot, even the one who does nothing ("Toto still sits beneath the basket") |
| the camera side | "from the same sideline" |
| the light and the place | the scene's background carries them; do not re-describe |
| the length of the beat | one continuous action per shot; a "go get" plus the next beat over ~8 s is two shots |
Closing pictures are guesses; last frames are facts. Draw the next shot only after the previous one is filmed, from its last frame; if you refilm a shot, take its last frame again for the shot after it. Thrown to another person: end shot A on the throw, open shot B on the catcher already looking at the incoming ball - never show the flight twice. A hand-off stays inside one shot. If the object is meant to stay behind, say so, or the model brings it along.