THE PLAYBOOK · W3CHACK
How to play Classic Sudoku
Read the aim of Classic Sudoku, then make your first move. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Look at what changes after your first action. Read the objective before making your first input. Use the example below to understand a decision.
A careful first round
Before your first action, say what you are trying to achieve. Then compare the result with the goal. Refer to the controls when needed.
Your goal
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Read that aim before choosing your first action. Keep the controls in easy reach.
Step by step
- Select an empty cell. The original clues cannot be edited.
- Choose a symbol from the number pad, or type it on a keyboard.
- Turn Notes on to record candidate symbols without committing an answer.
- Use Check entries to check your filled values. Hint reveals one value from the verified solution.
- 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. A careful first action helps you become familiar with the layout. Make sure you are interacting with the game rather than the surrounding page.
A useful example
On one puzzle in this collection, row 1, column 2 has 9 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Use the example as a guide rather than a substitute for reading your board. Keep the controls nearby.
Watch out for this
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Compare the situation with the worked example. Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow.
Common questions
On this playing page, what is the goal of Classic Sudoku?
For clarity: Fill all cells with 1–9; do not repeat a symbol in any row, column or region.
Before I begin, how do I control Classic Sudoku?
For clarity: 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.
For a quick reminder, what example helps explain Classic Sudoku?
On one puzzle in this collection, row 1, column 2 has 3 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
For a quick reminder, what should I watch out for in Classic Sudoku?
The key detail is this: Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
While reading the Guide, what format does Classic Sudoku offer?
For clarity: Play using the solo mode shown on this page. Read the controls before starting a new round.
While learning, which play mode does Classic Sudoku use?
The key detail is this: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.