> ## Documentation Index
> Fetch the complete documentation index at: https://patterns.heurilens.com/llms.txt
> Use this file to discover all available pages before exploring further.

# UX Laws

> Classic UX laws interpreted as measurable behavioral patterns that reveal friction, hesitation, and decision breakdowns.

## UX laws describe human behavior — not interface rules

UX laws are often presented as formulas or shortcuts.

But UX laws are not design tricks.
They are **observations of how humans perceive, decide, and act**.

Heurilens treats UX laws as:

* behavioral tendencies
* decision constraints
* measurable risk amplifiers

A law matters only when it **shows up in user behavior**.

## From laws to observable signals

UX laws become useful when translated into:

* what users hesitate on
* where they slow down
* when they make mistakes
* why they abandon progress

Heurilens maps UX laws to **real product signals**, not abstract advice.

## Core UX laws, interpreted through behavior

<AccordionGroup>
  <Accordion title="Hick’s Law — Decision complexity" icon="brain">
    The more choices users face, the longer decisions take.

    **When this law is violated, users:**

    * hesitate before acting
    * scan options repeatedly
    * postpone decisions

    **Observable signals**

    * delayed first interaction
    * option re-scanning
    * abandonment without action

    **Typical product situations**

    * overloaded menus
    * dense pricing tables
    * too many CTAs competing

    **Heurilens modules**

    * Cognitive Load
    * Visual Hierarchy
    * First Impression Breakdown
  </Accordion>

  <Accordion title="Fitts’s Law — Effort to act" icon="hand-pointer">
    The time to interact depends on target size and distance.

    **When this law is violated, users:**

    * misclick
    * avoid actions
    * slow down unnecessarily

    **Observable signals**

    * repeated clicks
    * missed targets
    * delayed interaction

    **Typical product situations**

    * small CTAs
    * crowded touch targets
    * distant primary actions

    **Heurilens modules**

    * Interaction Design
    * Mobile UX
    * Technical UX
  </Accordion>

  <Accordion title="Miller’s Law — Cognitive capacity" icon="layer-group">
    Humans can process a limited number of items at once.

    **When this law is violated, users:**

    * feel overwhelmed
    * forget context
    * abandon early

    **Observable signals**

    * rapid scrolling
    * incomplete tasks
    * shallow engagement

    **Typical product situations**

    * dense dashboards
    * long unstructured content
    * excessive form fields

    **Heurilens modules**

    * Cognitive Load
    * Information Architecture
    * Forms CRO
  </Accordion>

  <Accordion title="Jakob’s Law — Familiarity expectation" icon="repeat">
    Users expect products to work like others they already know.

    **When this law is violated, users:**

    * make incorrect assumptions
    * hesitate despite clarity
    * lose confidence

    **Observable signals**

    * misaligned clicks
    * repeated corrections
    * slowed navigation

    **Typical product situations**

    * unconventional navigation
    * reinvented patterns
    * unexpected interaction logic

    **Heurilens modules**

    * Consistency
    * User Flow
    * Interaction Design
  </Accordion>

  <Accordion title="Law of Proximity — Grouping perception" icon="object-group">
    Items close together are perceived as related.

    **When this law is violated, users:**

    * misinterpret relationships
    * struggle to prioritize
    * scan repeatedly

    **Observable signals**

    * attention fragmentation
    * delayed comprehension
    * incorrect interactions

    **Typical product situations**

    * poorly grouped forms
    * unclear content sections
    * crowded layouts

    **Heurilens modules**

    * Visual Hierarchy
    * Information Architecture
    * First Impression Breakdown
  </Accordion>

  <Accordion title="Law of Prägnanz — Simplicity bias" icon="wand-magic">
    Users perceive complex forms as simpler patterns.

    **When this law is violated, users:**

    * struggle to see structure
    * feel cognitive strain
    * disengage

    **Observable signals**

    * scanning without progress
    * delayed decisions
    * early exits

    **Typical product situations**

    * visually noisy pages
    * inconsistent layouts
    * unclear hierarchy

    **Heurilens modules**

    * Visual Hierarchy
    * Cognitive Load
    * Emotional Design
  </Accordion>

  <Accordion title="Peak–End Rule — Memory bias" icon="star">
    Users judge experiences by peaks and endings.

    **When this law is ignored, users:**

    * remember friction more than success
    * avoid returning
    * hesitate next time

    **Observable signals**

    * drop-offs near completion
    * low repeat engagement
    * negative post-task behavior

    **Typical product situations**

    * frustrating checkout endings
    * abrupt confirmations
    * unresolved errors

    **Heurilens modules**

    * Emotional Design
    * Forms CRO
    * UX Risks
  </Accordion>

  <Accordion title="Von Restorff Effect — Distinctiveness" icon="bullseye">
    Items that stand out are more likely to be remembered.

    **When this law is misused, users:**

    * focus on the wrong element
    * miss primary actions
    * delay decisions

    **Observable signals**

    * secondary-first clicks
    * ignored CTAs
    * attention misalignment

    **Typical product situations**

    * overly styled secondary elements
    * weak primary CTAs
    * visual noise

    **Heurilens modules**

    * Visual Hierarchy
    * First Impression Breakdown
    * Interaction Design
  </Accordion>
</AccordionGroup>

## UX laws rarely fail alone

UX law violations usually compound.

For example:

* Hick’s Law + Miller’s Law → overload
* Fitts’s Law + Mobile UX → silent friction
* Jakob’s Law + Consistency → trust erosion

Heurilens detects **clusters**, not isolated laws.

## Why UX laws matter in Heurilens

UX laws explain **why patterns exist**.

Patterns explain **what is broken**.

Metrics explain **how severe it is**.

Together, they form a complete UX intelligence loop.

## Related patterns

<CardGroup cols={2}>
  <Card title="Cognitive Load" icon="brain" iconColor="orange" href="/modules/core-ux/cognitive-load">
    Many UX laws break under overload.
  </Card>

  <Card title="Visual Hierarchy" icon="layer-group" iconColor="orange" href="/modules/core-ux/visual-hierarchy">
    Perception laws drive hierarchy clarity.
  </Card>

  <Card title="Interaction Design" icon="hand-pointer" iconColor="orange" href="/modules/interaction-flow/interaction-design">
    Laws shape interaction efficiency.
  </Card>

  <Card title="UX Metrics" icon="chart-line" iconColor="orange" href="/modules/advanced/ux-metrics">
    Laws become actionable through metrics.
  </Card>
</CardGroup>

<Card title="See UX law violations on your product" icon="sparkles" iconColor="orange" href="https://heurilens.com/auth/signup">
  Run an analysis and observe how UX laws manifest in real user behavior.
</Card>