Laws of Perception · gestalt
Figure–Ground
Playable Play this law (~3 min)or keep reading below ↓
The eye instantly splits any scene into a figure (the thing to attend) and ground (the backdrop). Interfaces steer this with contrast, blur, shadow and dimming — a modal works because everything behind it visibly becomes "ground."
Where it comes from
Danish psychologist Edgar Rubin formalised figure–ground in 1915 with his famous vase — an image you can see as a white vase or two black faces, but never both at once. His point: perception assigns one region "object" status and the rest "background," every waking moment. A designer's dimmed overlay is Rubin's vase, weaponised politely.
Origin: Rubin's vase, 1915
In the wild
- Modal dialogs
The dimmed overlay demotes the whole page to background; the dialog becomes the only figure that matters.
- Mobile bottom sheets
The sheet's shadow and the darkened content behind establish what's actionable right now.
- Hero sections
Text over a darkened photo reads instantly because the overlay forces the type to be figure.
Further reading
Don't just read it — feel it.
Play the 3-minute game and let your own reactions prove the law.
Play the lesson