You’ve no doubt noticed how often items are grouped into threes. Because you’re a writer, think about well-known stories . . . Goldilocks and the Three Bears . . . the Three Little Pigs . . . the Three Musketeers. Marketing slogans often use three words. “Coke adds life.” “Finger-licking good,” and many more.

Why is three so effective in reaching the human mind? There are several theories. (Note that I listed three.)

Three is the smallest number that can form patterns, therefore it’s easier for our minds to grasp.

People can recall three items, but remembering a fourth or more becomes a challenge.

Many parts of our natural world are in threes. For example, there is solid, liquid, and gas. And a fire starts if there is fuel, heat, and oxygen. The theory is that because the physical world often groups items into threes our minds tend to also do so.

Any or all of these may explain the attraction of three, although no one knows for sure what makes the concept effective. But although it’s uncertain why the number is powerful, writers can use three to their advantage.

Say you’re creating an outline or writing a speech. Ideally, create three major points and perhaps three sub points for each of the major points.

Or if you’re writing fiction, have your protagonist try to achieve a goal three times. The first two times he fails but succeeds on the third. Or the opposite—your antagonist succeeds twice, but the third time the “good guy” triumphs. In either case, the first two items build tension; the third resolves it.

Don't press the use of the concept of threes. Use however many points, events, or words you need. But your audience will be comfortable with three. They’ll grasp your point more quickly and remember it longer than if you used another number.

The following clean joke demonstrates the effectiveness of using three in your storytelling. Not only are there three characters, but note that the last one performs three actions. Read the joke (and I hope you’ll laugh!) but then think about what would happen if there were only two characters, or if there were four. Also think about whether the punchline would be less effective if the final character only performed two actions.

Three men (categorize them however you want—three of your friends, graduates of three different colleges, whatever) traveled together to a foreign country. While there they got into some trouble . . . and a judge sentenced them to death by guillotine. So the first man is under the guillotine and the judge says, “Do you have any last words?” He replies, “Yes, tell my wife I love her very much.” So the guillotine falls, but stops just short of the man’s neck. The judge says, “It must be God’s will that he lives. Let him go!” Then the second man goes under the guillotine and the judge says, “Any last words?” The man says, “Yes, tell my family they’ve made my life complete.” So the guillotine falls, but again stops just short of his neck. The judge says, “It’s God’s will that he lives. Let him go!” Finally the last man is under the guillotine, and the judge says, “Do you have any last words?” The man looks up at the guillotine, thinks for a moment and says, “You know, I bet if you just placed a little grease on this thing . . .”

You’ll tell your story more effectively with three of whatever item you’re writing about.