Character motion contract

Principle

Character motion is behavior, not mascot decoration. One cross-modal contract must align anatomy, personality, speech authority, emotion, movement, sound, context, accessibility, and performance. Demonstrations use original neutral characters only.

Behavior manifest

Declare character ID; role and relationship to the brand voice; allowed channels; speech attribution; prohibited critical domains; rig/anchor version; pose and emotion vocabulary; intensity range; idle behavior; gaze and attention; movement verbs; timing/easing families; sound/haptic permissions; interruption and concurrency policy; reduced-motion, no-audio, static-image, and text equivalents.

Recipe contract

Each recipe (idle, acknowledge, celebrate, guide, recover) declares trigger, user benefit, allowed states, maximum duration/repetition, interrupt behavior, transform origin, affected anchors, semantic completion event, input modality behavior, performance budget, and accessibility alternatives.

Never celebrate destructive action, block recovery with a performance, shame a failure, animate indefinitely to demand attention, speak unattributed copy, or place character humor in security, payment, consent, safety, or data-loss flows.

Motion hierarchy

Start with stillness. Use small acknowledgement for direct manipulation, guided motion only when it clarifies causality, and celebration proportional to achievement. Preserve silhouette and anatomical constraints at motion extremes. Sound and haptics reinforce the same event but remain optional and separately controllable.

QA evidence

Storyboard and key-pose review; silhouette/rig bounds; 30/60 Hz and low-end device performance; interruption and rapid-repeat tests; reduced-motion and static equivalence; screen-reader and keyboard flow; sound-off; localization with attributed speech; seizure/vestibular review; cross-channel consistency.

Agent rule

Agents select approved recipes and parameter ranges. They may not generate new body mechanics, emotional extremes, speech permissions, or critical-context exceptions from a reference character's behavior.