How to Play Classic Sudoku

THE PLAYBOOK · 78JMW

How to play Classic Sudoku

Open Classic Sudoku, check the instructions and begin a round. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Keep the game area visible while you use its controls. Check the rule that explains your first action. Choose a clear next step rather than rushing through the instructions.

A careful first round

Before your first action, say what you are trying to achieve. Then compare the result with the goal. Make the next step deliberately.

Your goal

Fill all cells with 1–9; do not repeat a symbol in any row, column or region. An attractive position is not enough unless the goal is met. Check the rules when you are unsure.

Step by step

1. Select an empty cell. The original clues cannot be edited.
2. Choose a symbol from the number pad, or type it on a keyboard.
3. Turn Notes on to record candidate symbols without committing an answer.
4. Use Check entries to check your filled values. Hint reveals one value from the verified solution.
5. Complete the board, or choose New puzzle for another board.

Controls

Tap or click a cell and use the number pad. Keyboard: arrows select cells; digits (and A–G on 16×16) enter values; Backspace erases. On a smaller screen, keep the active part of the board within view. Use one clear input at a time.

A useful example

On one puzzle in this collection, row 1, column 3 has 2 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Focus on why the action is allowed, not only its outcome. Choose a deliberate next step.

Watch out for this

Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Take a moment to reassess the position before continuing. When a decision goes wrong, compare it with the common mistake described below. Start again only when you intend to leave the current round.

Common questions