Interior designers have a special talent for knowing exactly how to place items into a space. What's their secret? The design rule is's the Rule of Three!

If there is such a thing as a "magic number" for assuring good visual design, it's 3. Artists and designers use visual elements in sets of 3 to help their compositions feel more harmonious. Left, center, right. Small, medium, large. It's a series that's familiar, balanced, and orderly. Three is important when it comes to structure, it has symbolic significance to many religions, and it has a natural connection to the way we process information.

As a design principle, combinations of 3 are considered more engaging and memorable. Our brains are programmed to find patterns and respond to proportions. Our eyes seek to keep moving. You can create this kind of visual interest in your own decor by applying the Rule of Three.

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5 Design Rules You Can Break

COMPOSITIONdesign rules to know rule of three

  • Arrangements composed of an odd number of objects are more appealing - a centerpoint anchors the arrangement and the other pieces add symmetry.
  • Move larger furniture into groupings. Three pieces with similar visual weight will create cozy conversation zones.
  • Working with a common shape in the room also creates cohesion. A round mirror, round table, and the curve of a sofa arm encourage you to think in threes.


  • Varying size and scale engages a sense of depth.
  • Three levels of height draw the eye into following a triangular path.
  • Using patterns of 3 different scales (small, medium, large) or motifs (plaid, stripe, floral) in a room adds dimension and texture.


  • A common formula for a color palette consists of a main color, a secondary color, and an accent color.
  • If you introduce a pop of color, repeat it in two more places to keep the observer's gaze traveling around the room.
  • Layered lighting improves color and ambience. Most plans incorporate 3 sources: natural illumination from windows, overhead fixtures, and task lighting.