I rerolled one AI video prompt 10 times. The prompt was the problem, not the dice.

Jun Heo — Fri, 25 Sep 2026 02:22:42 +0000

When an AI video clip comes out wrong, the reflex is to hit generate again. Sometimes that's right: video models are probabilistic, and some takes are just weaker than others.

But when the same thing goes wrong ten times in a row, it's not the dice.

The experiment

I wanted a 5-second vertical clip of a coffee spill in a café. One line:

A barista bumps a customer's elbow and a paper coffee cup slips and spills onto the café floor next to white sneakers, slow motion, handheld close-up, warm morning light.

I generated it 10 times with the same settings (9:16, 5 s).

Top row (before): the cup falls, rolls, lands upright. The spill, which was the whole point, barely happens in any of them.

Bottom row (after): the same app and settings, with a rewritten prompt for just the spill. The splash lands on the sneaker in 10 out of 10.

What was actually wrong

Nothing exotic. Two mistakes that show up in almost every failing video prompt:

1. Two actions fighting in one clip. "A barista bumps an elbow" and "the cup spills." In 5 seconds the model has to stage a bump, a slip, a fall and a splash. It picks some of that and drops the rest.

2. The key action was the last clause. The spill came after the barista, the elbow, the cup and the café. Models tend to weight what comes first. Mine kept delivering the setup and skipping the payoff.

A real film crew would never shoot it that way. The director would break it into shots. The DP would frame the spill tight at floor level with a locked camera, because liquid physics is hard. The script supervisor would flag that one clip is trying to do two things.

So the rewrite for the spill shot was:

Extreme close-up at floor level, 50mm lens, locked-off camera, on clean white leather low-top sneakers standing on a polished grey concrete floor. Black coffee splashes down onto the sneaker toe and spreads across the concrete in a wide splatter, droplets bouncing. 2x slow motion. Warm morning sunlight raking from camera-left, hard highlights on the wet coffee. 35mm film look, fine grain.

One subject. One action, stated first in its own sentence. One camera instruction. The bump becomes its own shot.

It isn't perfect. In a few takes the coffee reads a bit syrupy, so the next change would be dropping slow motion to real time. But now I'm fixing texture, not whether the shot happens at all.

The checklist

These are the rules I now run every video prompt through:

One action and one camera move per shot. Two actions means two shots.
Lead with the action. Put the event you need first, with a clear start and end.
Describe the frame, not the feeling. "Tense" isn't something a camera can see. "Jaw clenched, eyes on the door" is.
Name a lens and a light source. "50mm, window light from camera-left" does more than "cinematic."
Frame hard physics tight. Pours, splashes, hands and small objects: close-up, simple background, locked camera.
Paste character descriptions verbatim in every shot. Paraphrasing a character gives you a different person.
No readable text in frame. Add it in the edit.
Delete empty quality words. "8k, masterpiece, stunning" push out words that help.
After a bad take, change one thing. If you change five things you learn nothing from the reroll.

I turned it into an agent skill

Running that checklist by hand gets tedious, so I packaged it as an open-source agent skill: ai-film-crew. It runs your idea past seven roles, each with one job:

Role	Catches
Director	mood-only beats, slow openings
Production designer	characters drifting between shots (writes a continuity bible)
DP	combined camera moves that warp geometry
Gaffer	flat, evenly lit "AI look"
Editor	shots longer than the model can generate
Sound	audio cues sent to silent models
Script supervisor	continuity, feasibility, slop; can veto any shot

It has three modes:

Plan: idea in, shot list and one prompt per shot out
Fix: paste a failing prompt, get the problems ranked and a rewrite
Review: describe a bad clip, get the one change to make before rerolling

It works with Wan, LTX, HunyuanVideo, Kling, Veo, Seedance, Hailuo and Runway, and it runs in Claude Code, Codex, Cursor or anything else that reads SKILL.md:

npx skills add HEOJUNFO/ai-film-crew

Then just ask for a video:

> 15s vertical ad for a handmade ceramic mug, for Kling
> this prompt keeps failing: "a chef flips a pancake in slow motion, cinematic, 8k"

The coffee example and a full Kling ad plan are in the repo's examples/ folder.

Disclosure

I work on Ludyte, an AI video app, and both rows of clips above were generated there. The skill is MIT-licensed and model-agnostic; nothing in it depends on Ludyte.