The Rule of Three

After mind mapping, Meera has eight good ideas for her 20-minute talk. Eight is too many for a room to hold. People listening cannot scroll back up to check what point four was. She needs a shape that an audience can carry in their heads, and the most reliable shape is three.

The rule

Three points fit in a listener's head; ten fall out.

The rule of three says that ideas grouped in threes are easier to follow and to remember. Three is enough to feel complete (a beginning, a middle and an end) and small enough to hold without effort. You can use it at every scale:

• The whole talk in three parts.
• A single sentence with a three-part list: "fast, free and honest".
• A story in three beats: the situation, the problem, the way through.

The rule works best with signposting: telling the audience the shape before you fill it. "There are three things to do: ask, read, react. First, ask..." Now every listener knows where they are and how much is left.

It is a guide, not a law. Two strong points beat two strong points plus a weak one invented to make three. The real lesson is few and grouped, and three is usually the sweet spot.

The shortcut

Bucket and cut. Make three buckets, each with a short label, and give the labels the same grammatical form, such as three verbs or three questions. Drop every idea into a bucket. Anything that fits none of them is cut, or saved for another piece.

A common mistake is splitting one point in two, or gluing two unrelated points together, just to hit the number. If the buckets feel forced, the labels are wrong. Try different labels before you try forcing the ideas.

Drills

Answer fast — trust the rule.

Remember

• Three points fit in a listener's head; ten fall out.
• Shortcut: bucket and cut. Three parallel labels, and whatever fits none is cut.
• Trap: padding to reach three, or forcing ideas into buckets that don't fit.