CRITICALFailure Reference

Pika Labs Hand & Finger Artifact — Pre-Generation Risk Reference

Technical Classification

Hand-Anatomy Topology Failure

Hand-Anatomy Topology Failure is one of Pika's highest-frequency rejection modes. Hands occupy a small fraction of training pixels relative to their anatomical complexity; the model produces statistically plausible but topologically impossible hand structures: 4 or 6 fingers, knuckles bending laterally, fingers fusing into a paddle shape during motion. The failure is especially severe on prompts involving hand manipulation or sign-language gestures.

How to identify this failure

✕Six fingers visible on one hand at any frame
✕Thumb pointing backward or duplicated
✕Knuckle bending in non-anatomical direction
✕Fingers fusing into single mass during motion
✕Hand orientation flipping between palm and back

Real generation examples

Prompt used

"Hands assembling a model airplane on a workbench"

Failure observed @ 0:02

Left hand showed 6 fingers at 0:02; fingers fused at 0:04 during pickup motion

Prompt used

"Sign language teacher signing the alphabet"

Failure observed @ 0:01

Thumb pointing backward at 0:01; fingers melted during transition between letters

Documentation strength

If you need to escalate

VERY HIGH — Pika support treats hand failures as a recognised critical mode under their Anatomy escalation category. Refunds routine with timestamped evidence.

AVA is a pre-purchase prevention tool, not a post-purchase recovery tool. Platforms generally do not guarantee credit refunds for output-quality failures; goodwill credits are at each platform's discretion. The strength rating reflects how well-formed your support ticket can be, not a promised outcome.

Prevention + documentation steps

01
Score your prompt before you generate
Run your prompt through AVA's pre-flight scoring against the Hand-Anatomy Topology Failure pattern. Green light = generate. Yellow/red = rewrite using the suggested fix before you commit credits.
02
Capture Generation ID + timestamp if it failed anyway
Find the Generation ID in the URL or share link. Note the exact time when the Hand-Anatomy Topology Failure first appears (e.g. "failure first visible at 1.2s"). Timestamped evidence is significantly stronger than a general complaint.
03
Use the correct technical term in your support ticket
Describe this failure as "Hand-Anatomy Topology Failure". This term maps to a recognised internal workflow in the support system and routes the ticket to the right team.
04
Submit via the correct support channel
Runway has no direct email intake. Pro+ plan: open the in-app AI Assistant (help widget bottom-right of app.runwayml.com), describe the failure with the technical term, attach evidence. Free/Standard plan: human support isn't available — your channel is Discord #community-help with @On Call - Moderators.

Frequently asked questions

Does Pika support response credits for hand artifacts?

Yes. Submit the Generation ID with the technical term "Hand-Anatomy Topology Failure" and a timestamped screenshot of the impossible geometry. Pika support refunds documented hand failures under their Anatomy category.

Why are hand failures so common on Pika?

Hands are anatomically dense (27 bones per hand, 14 phalanges) but statistically sparse in training data. The diffusion loss under-constrains hand topology relative to faces, which receive disproportionate training weight.

How do I avoid hand failures on Pika?

Frame hands further from camera. Avoid prompts where hand motion is the primary action. Keep clips ≤4 seconds when hands are visible. AVA's pre-flight scanner flags hand-risk prompts before submission.

Score your prompt

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Paste your prompt and the platform you intend to use. AVA returns a red/yellow/green score against this specific failure mode plus a concrete rewrite if the risk is high.

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