What is the mysterious 'Rule of Three'?

Decoding the Rule of Three.

For thousands of years, the number three has been imbued with a mystique; a power that has seen it placed at the centre of rules governing effective communication within all aspects of culture.   From rhetoric to religion, mastery of the Rule of Three is the key to power.  
Decoding the Rule of Three.

When it comes to communicating ideas, the intelligentsia has always understood how human beings are programmed to process information through instinctive pattern recognition.   

Of course, to communicate effectively, the pattern needs to be as small as possible. So what is the smallest number required to make a pattern?   


Three is the smallest number required to make a pattern. 

And there lies its power. In its many forms, the Rule of Three, at heart, utilises simple three-element patterns to communicate complex ideas effectively. The pattern works because it is short. Memorable. Powerful.   

That’s why the Rule of Three is so pervasive throughout history:  

  • In physics – Newton’s three rules of motion.
  • In music – musical triads: the three-note building blocks of musical harmony.
  • In religion – the concept of the triple deity, common throughout world mythology, such as the holy trinity.
  • In art and photography – principles of composition, such as the rule of thirds…

 Of course, as copywriters, we’re primarily interested in writing and rhetoric. That’s where the Rule of Three really comes into play:  

  • Aristotle’s three unities – dramatic unity of time, place and action.
  • The three dramatic conflicts – internal, relational and external.
  • The three-act structure – beginning, middle and end, used throughout drama and in the modern cinematic trilogy.

The list goes on. The Rule of Three has also been used to encapsulate some of history’s most powerful ideas. For example, using rhetorical devices such as the Hendiatris, where three successive words are used to express a central idea:  

  • “Veni, vidi, vici.” (“I came, I saw, I conquered”) Julius Caesar.
  • “Liberté, Égalité, Fraternité.“ (“Liberty. Equality. Fraternity.”) The national motto of France.
  • “Citius, Altius, Fortius.” (Swifter, higher, stronger”) The Olympic motto
  • “Location, location, location.” Harold Samuel.
  • “Education, education, education.” Tony Blair.

And when it comes to speeches, some of the most powerful men in history, including Winston Churchill and Barack Obama – fill their speeches with Rule of Three techniques to persuade, to assure, and to rule. No small testament to its power.   And what of marketing?   

Rule of Three copywriting techniques are commonly used within marketing and advertising. The two most common uses of Rule Three relate to marketing theory and slogan creation.  

Marketing theory

In marketing theory, American advertising  pioneer, E. St. Elmo Lewis laid out his three chief copywriting principles, which he felt were crucial for effective advertising:  

"The mission of an advertisement is to attract a reader, so that he will look at the advertisement and start to read it; then to interest him, so that he will continue to read it; then to convince him, so that when he has read it he will believe it. If an advertisement contains these three qualities of success, it is a successful advertisement."*


  These three copywriting principles formed the backbone of the widely-used “Attention Interest Desire Action” (AIDA) marketing model – a system of steps with which to engage an audience­ effectively.   

The AIDA model has itself evolved into a Rule of Three technique with its four elements being distilled into the three simple steps of the "Cognition Affect Behaviour" (CAB)** copywriting model:   ▪   Cognition (Awareness or learning) ▪   Affect (Feeling, interest or desire) ▪   Behavior (Action). 

Slogan creation

  Unsurprisingly, the Rule of Three has been used to create some of the most powerful advertising slogans of the twentieth century. Each time: three little words. Instantly an entire brand is conjured up in your mind…  

  • Just do it
  • Vorsprung durch technik
  • Beanz Meanz Heinz
  • Your flexible friend
  • I’m lovin’ it
  • Finger lickin’ good
  • Every little helps
  • Snap! Crackle! Pop!
  • Diamonds are forever
  • Taste the difference

* “Catch-Line and Argument,” Vol. 15, February 1903, p. 124. Other writings by E. St. Elmo Lewis on advertising principles include "Side Talks about Advertising," The Western Druggist, Vol. 21, February 1899, p. 65-66; Financial Advertising, published by Levey Bros. in 1908; and, "The Duty and Privilege of Advertising a Bank," The Bankers' Magazine, Vol. 78, April 1909, pp. 710-11.   

**J. A. Howard, Marketing Management, Homewood 1963; cf. M. B. Holbrook, "Howard, John A." in: P. E. Earl, S. Kemp (eds.), The Elgar companion to consumer research and economic psychology, Cheltenham 1999, p. 310-314

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