Character & Mascot Systems

Copyright-safe synthesis of production patterns popularized by brand systems like Duolingo's public illustration bible.

When to use a character

• Teaching, celebration, empty states, onboarding — not security/legal.
• Characters need a job, not decoration.

Anatomy sheet (required)

1. Construction grid / proportions
2. Face zone limits
3. Limb articulation limits
4. Silhouette readability at 24/48/128px
5. Emotion set (allowed + forbidden)
6. Pose vocabulary
7. Cropping rules (never cut through joints awkwardly)
8. Color roles on character vs background
9. Misuse gallery (stretch, rotate, recolor, add props freely, etc.)

Complexity budget

• Prefer flat perspective + limited overlap.
• Cap simultaneous decorative details.
• One focal expression per frame.

Anti-imitation

• Do not copy Duo or any proprietary mascot geometry, colors, or catchphrases.
• Transfer the process (anatomy sheet + misuse gallery), invent original IP.

Linked rules

• rule.brand.illustration-grammar
• rule.brand.personality-system

Shape-language production rules (transferable pattern)

Observed on Duolingo /illustration/shape-language (2026-07-13 scrape):

Rule class	Transferable constraint
Primitive set	Limit to a small closed set of base shapes (e.g. rounded rect / circle / rounded triangle)
Edge style	Consistent corner language (all rounded vs all sharp) — mixed edges break system
Complexity budget	Explicit good range of shape counts; too few = abstract, too many = noisy
Perspective	Flat perspective; depth via limited, consistent cues
Shadow grammar	One shadow language (shape + placement + relative darkness), never freeform
Color roles	Named functional grays + limited accent families; discourage ad-hoc extra fills
Rhythm	Vary visual weight; avoid equal-sized repeated blocks

Build an original primitive set for each brand. Never reuse Duo geometry or palette names as product truth.