Katechon ArcA prompt structure that works
| Field | Example |
|---|---|
| Framing | Medium close-up, eye level |
| Subject | Maren, the herbwoman (reference attached) |
| Action (one) | She wraps a bandage around the boy's arm |
| Setting | Her cottage, night, snow at the window (reference attached) |
| Light | A single oil lamp on the table, warm, low |
| Sound or line | She says quietly: "Hold still." |
| Length | 6 seconds |
Rules from our productions
- One action per shot. Two actions usually means one of them is skipped or merged.
- Name a concrete light source. "A single lamp" beats "moody lighting".
- Colours on the world, not on skin. "Cold blue shade on her face" produced a blue-skinned character; put the blue on the walls.
- State rules positively and where they apply. "The red balloon is the only red" made the image model paint balloons into set sheets. "No red in sets or wardrobe" plus "empty plate, no balloons" in set descriptions fixed it.
- Tag continuity in every shot. Helmets flipped between cuts until each shot stated helmet state.
- Name who speaks. Unattributed dialogue can come out as a narrator's voice over the wrong shot.
- Avoid famous-face archetypes. A description that reads like a well-known actor can get shots blocked as a lookalike.
- Put style in the project, not the shot. Medium, palette and lens apply to every frame; restating them per shot invites drift.
Prompts are not enough for a series
However good the prompt, the model reinterprets words every time. For anything with recurring characters, attach reference images; see text, image or reference to video. Rewriting a shot's prompt cost us more than recasting a character's reference when a face kept getting blocked.
Iterate cheaply
Test a prompt on a storyboard frame (13 credits in Arc) or on Seedance 2.0 Mini (47 credits for 5 seconds at 720p) before rendering the final take on a pricier model. Arc can preview the final prompt for any shot before generating it.
Where Katechon Arc fits
Arc writes the per-shot prompt from the script plan, references and project style, and lets you preview and edit it before generation.
Arc's prompts target Seedance 2.0 models; prompt conventions for other models' own apps differ, and Arc does not offer them.