Story · 2026-10-18 · 2 min read

The legend of the rice on the chessboard

A famous legend about a clever inventor, a king and 64 squares, and a number too big to imagine.

This is a legend, told for hundreds of years. A king loved the new game of chess so much that he asked its inventor what reward he wanted.

The inventor smiled: "Place one grain of rice on the first square of the board, two on the second, four on the third, and keep doubling for all 64 squares."

The king laughed. What a small prize! But his advisers started to count. By the 11th square it was 1,024 grains. By the 21st square, over a million. On the last square alone, there would be 9,223,372,036,854,775,808 grains.

[rice]

In all, the board needs 18,446,744,073,709,551,615 grains of rice, far more than all the rice ever grown on Earth. The legend says the king had to admit that the inventor was cleverer than him.

It is a story about doubling, the same idea that makes a small habit, like ten minutes of puzzles a day, grow into something huge over a year.