| name | lawofux |
| description | Apply Laws of UX (lawsofux.com) principles to design and build winning customer experiences. 30 psychology-backed UX laws covering usability, perception, memory, decision-making, and interaction design. Use when the user says 'lawofux', 'laws of ux', or asks to design an app, modify UI/UX, review UX, build a user interface, improve user experience, create a landing page, design a dashboard, or any task involving UI design, app design, or UX optimization. |
Laws of UX
Apply 30 evidence-based UX laws from lawsofux.com to every design decision. Reference: references/laws.md for full details on each law.
Workflow
1. Analyze the Task
Identify which UX laws are most relevant to the current design task:
| Task Type | Primary Laws to Apply |
|---|
| Navigation/IA | Hick's Law, Serial Position Effect, Miller's Law, Chunking |
| Forms/Input | Postel's Law, Doherty Threshold, Goal-Gradient, Tesler's Law |
| Landing/Marketing | Aesthetic-Usability, Von Restorff, Peak-End Rule, Fitts's Law |
| Dashboards/Data | Cognitive Load, Law of Proximity, Chunking, Law of Pragnanz |
| Onboarding | Paradox of Active User, Hick's Law, Zeigarnik Effect, Goal-Gradient |
| E-commerce | Choice Overload, Serial Position, Jakob's Law, Peak-End Rule |
| Mobile | Fitts's Law, Miller's Law, Flow, Doherty Threshold |
| Settings/Config | Tesler's Law, Pareto Principle, Hick's Law, Occam's Razor |
2. Apply Laws During Design
For every UI component or screen, run through this checklist:
Reduce Friction
- Choices minimized at each step? (Hick's Law)
- Info chunked into digestible groups? (Miller's Law, Chunking)
- System responds <400ms? (Doherty Threshold)
- Complexity absorbed by system, not user? (Tesler's Law)
Guide Attention
- Primary CTA visually distinct? (Von Restorff Effect)
- Important items at start/end of sequences? (Serial Position Effect)
- Related elements grouped spatially? (Law of Proximity)
- Similar elements styled consistently? (Law of Similarity)
Match Expectations
- Standard patterns used? (Jakob's Law)
- Input handled flexibly? (Postel's Law)
- Interface self-explanatory without docs? (Paradox of Active User)
- Design matches users' mental models? (Mental Model)
Drive Completion
- Progress clearly shown? (Goal-Gradient Effect, Zeigarnik Effect)
- Positive peak moments designed in? (Peak-End Rule)
- Touch targets large enough? (Fitts's Law — min 44px)
- Users can maintain flow state? (Flow)
3. Document Decisions
When presenting designs, briefly note which laws informed key decisions:
// CTA button: 48px height, high-contrast color (Fitts's Law + Von Restorff)
// Nav: 5 items max, key actions at edges (Hick's Law + Serial Position)
// Form: 3-step wizard with progress bar (Goal-Gradient + Chunking)
Quick Reference — Top 10 Laws for Every Project
- Jakob's Law — Follow existing conventions. Don't reinvent patterns.
- Hick's Law — Fewer choices = faster decisions. Progressive disclosure.
- Fitts's Law — Big targets, close to thumb. Min 44px touch targets.
- Miller's Law — Chunk content into groups of 5-7 related items.
- Doherty Threshold — Keep response times under 400ms. Use skeleton screens.
- Von Restorff Effect — One distinctive CTA per view. Don't over-highlight.
- Law of Proximity — Spacing defines grouping. Labels near their fields.
- Peak-End Rule — Celebrate completions. Smooth error recovery.
- Tesler's Law — Absorb complexity in code, not in the user's face.
- Postel's Law — Accept messy input gracefully. Auto-format.
Full Law Details
Read references/laws.md for complete descriptions, origins, takeaways, and application guidance for all 30 laws.
