references/qc

Translate the symptom into a failure code first: face or wardrobe changes are F1 identity drift, melting geometry is F3 warping. Then apply the cost ladder from L1 prompt edits upward, changing only one variable per retry.

Start at L1 with a prompt edit, then L2 parameter changes like shorter duration or lower motion strength. Only escalate to L4 keyframe rebuilds or L5 shot re-planning when lower rungs fail, and never skip levels without a documented reason.

After three failed generations of the same shot design, apply the three-strike rule: change the design by shortening, pushing in, simplifying, or splitting the shot. A fourth prompt rewording rarely produces new information.

Run three gates: a pre-generation plan check, a per-clip post-generation score, and a sequence gate on the assembled cut requiring 85/100. Any blocker such as identity breaks, extra fingers, or vanished props vetoes delivery regardless of score.

That symptom is F2, caused by prompts describing a picture rather than an event, static keyframes, or motion strength set too low. Rewrite the prompt with body, cloth, and environment motion layers and rebuild the keyframe mid-gesture.

Irreducible failures include sustained precise hand-object contact, readable long text, multi-person contact, exact mirroring, and recognizable crowds. These must be rewritten at the storyboard stage as intent-to-offscreen-to-result or replaced with stills, practical footage, or compositing.