What is Sudoku?
Sudoku is a logic puzzle that looks like maths but needs none. If you can count to nine, you can play — here is everything you need to understand it.
The grid
A Sudoku is played on a 9×9 grid — 81 cells in total. That grid is divided into nine smaller 3×3 boxes. Some cells start with a number already filled in (the “givens”); the rest are empty and waiting for you.
The goal
Your job is simple to state: fill every empty cell so that each row, each column and each 3×3 box contains the digits 1 to 9 exactly once. No number may repeat within the same row, column or box.
There is no arithmetic involved — the digits are just symbols. You could play with nine different colours or letters instead. What matters is that each of the nine symbols appears once in every row, column and box.
No guessing needed
A proper Sudoku has exactly one solution, and that solution can always be reached by pure logic. You never have to guess: for every step there is a cell where only one digit can possibly go. Finding those forced cells is the whole game.
Where it comes from
The modern puzzle was designed in the late 1970s and popularised in Japan in the 1980s, where it got its name — short for a phrase meaning “the digits must be single.” In the mid-2000s it spread through newspapers worldwide and became a global phenomenon. Its appeal is timeless: simple rules, endless variety, and a calm, focused kind of challenge.