Beginners · The one rule · Your first number
How to Play Sudoku
Taught the way a first-timer actually learned it: one rule, one certain number at a time, and a pencil.
The one rule
Every row, every column and every 3×3 box must contain the digits 1 to 9 exactly once. That is the whole game. There is no adding up. A sudoku is solved by asking, over and over, “where is the only place this digit can go?” — and writing it in only when the answer is one cell.
Fifteen unscripted minutes: the author teaching his uncle his first sudoku on Puzzle 1 of the book. The pauses are the lesson.
Six moves, in order
Everything below was said out loud at a kitchen table in September 2026, to someone who had never done a sudoku. It worked.
Pick the fullest box
“I usually try to start with ones that are kind of mostly filled in.” A box with two or three gaps has two or three possibilities. A box with six gaps has too many.
Ask where a digit can’t go
Take one missing digit. Look along each empty cell’s row and column. “It can’t, because there’s an eight here.” Cross those cells off.
One cell left? Write it
“So we know a hundred percent — that’s an eight.” When exactly one cell survives, the digit goes there. That is the only kind of move you ever make.
Two cells left? Leave it
“If you write the nine in, it still might be able to go there. So you don’t want to write it in yet.” Try a different digit. Come back later; it will have narrowed.
Stuck? Switch to a row
“Instead of thinking of it in a square, change your brain to try to finish that row.” A row with one gap is a free number, and every number you place removes a possibility somewhere else.
Check with the last number
“That’s how you know you got it right — the last number works.” If the final digit in a box clashes with its row or column, something earlier was a guess.
What a first puzzle feels like
The first two or three numbers are slow. Then the grid starts giving them back to you: “it gets a little easier as you go along towards the end.” On an easy puzzle a complete beginner, with someone pointing now and then, finished the first grid in the book in about nine minutes and said, about a third of the way in, “Oh good. Now I can do it.” That sentence is the whole point of the first act of Sudoku with a Secret: seventy easy puzzles, so the click happens early and often.
Practice on a real page
Free, in your browser
Play the puzzles online — no account, no app, and the easy ones come first.
On paper, with a pencil
The book prints one 9×9 grid per 8.5 × 11 inch page with room to pencil candidates, and it opens with a “New to Sudoku? Start Here” page that teaches exactly this method.
Then the secret
Twenty of the 200 puzzles hide a shaded key. Here is how the escape-room layer works once you can solve.
Questions beginners ask
What is the one rule of Sudoku?
Fill the grid so every row, every column and every 3×3 box holds the digits 1 to 9 exactly once. No arithmetic, no adding up. It is a placement puzzle.
Where do I start?
The 3×3 box with the fewest gaps. Take one missing digit at a time and ask where in that box it could legally go. Place only the digits with exactly one possible cell.
Should I ever guess?
No. Every properly made sudoku has exactly one solution reachable by logic. If a digit could go in two cells, try another digit and come back. Use a pencil; “it always helps to have an eraser.”
How long does a first Sudoku take?
On an easy puzzle, about nine minutes with a little coaching; fifteen to thirty alone is normal. It gets faster quickly.
Do I need to be good at maths?
No. The digits could be letters or colours. Nothing is added, subtracted or counted beyond “which of 1 to 9 is missing here?”
Start on page five
Volume 1 opens with a Start Here page, then 70 easy puzzles before anything gets hard. $14.99 in paperback.
Get Volume 1 on Amazon ↗Or try the puzzles free first.