The rule of three is a writing principle that suggests that a trio of entities such as events or characters is more humorous, satisfying, or effective than other numbers. The audience of this form of text is also thereby more likely to remember the information conveyed because having three entities combines both brevity and rhythm with having the smallest amount of information to create a pattern.[1][2]

The story of Goldilocks and the Three Bears uses the rule of three extensively, with the protagonist examining three sets of three items in a house, finding only the third of each set to be satisfactory

Slogans, film titles, and a variety of other things have been structured in threes, a tradition that grew out of oral storytelling.[3] Examples include the Three Little Pigs, Three Billy Goats Gruff, Goldilocks and the Three Bears, and the Three Musketeers. Similarly, adjectives are often grouped in threes to emphasize an idea.