Hick's Law
The time it takes to make a decision grows logarithmically with the number of choices available.
Plain English
Hick's Law says: more choices = slower decisions. Every option you add to a navigation menu, a form dropdown, or a pricing page increases the cognitive load of choosing. This is not linear — the 10th option slows the decision more than the 2nd. The practical implication: ruthlessly reduce options. One primary CTA is faster than three. Five navigation items is faster than ten.
Research background
Formulated by William Edmund Hick and Ray Hyman in 1952: RT = b × log₂(n + 1), where RT is reaction time, n is the number of choices, and b is an empirically derived constant. The +1 accounts for the possibility of making no choice. This logarithmic (not linear) relationship means reducing choices from 10 to 5 creates more improvement than reducing from 5 to 2.
UI examples
✓ Applying the principle
A pricing page with 3 plans (Basic, Pro, Enterprise) converts better than one with 8 plans — fewer choices mean faster commitment.
✗ Violating it
A navigation bar with 12 items of equal visual weight — users pause significantly at each visit to re-evaluate what to click.
AI Prompt
Paste into Claude, Cursor, Bolt, or v0.
Apply Hick's Law: limit navigation to 5 items, show one primary CTA per section, and reduce any dropdown with more than 10 options using search or categorisation.