Game guide · 12530NET
Classic Sudoku: rules and examples
Try Classic Sudoku at your own pace and keep its objective in view. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Use the example below to understand a decision. Check the rule that explains your first action. Check the relevant rule before repeating a move.
Bring this focus to a round
Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart. Keep the objective visible.
Your objective
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Keep that objective in view throughout the round. The example below illustrates a decision.
A walkthrough of the rules
- 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.
Using the playing area
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. Contact us with the game and device if a control does not respond.
Learn from a sample situation
On one puzzle in this collection, row 1, column 3 has 9 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Apply the same reasoning to the position in your own round. Consider the next action carefully.
Check this before moving on
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. Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow.
Questions about this game
On this playing page, what is the goal of Classic Sudoku?
Fill all cells with 1–9; do not repeat a symbol in any row, column or region.
While reading the Guide, 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.
When I return, what example helps explain Classic Sudoku?
The key detail is this: On one puzzle in this collection, row 1, column 3 has 9 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
Before I begin, what should I watch out for in Classic Sudoku?
For clarity: Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
For my first round, what format does Classic Sudoku offer?
The key detail is this: Play using the solo mode shown on this page. Read the controls before starting a new round.
Which play mode does Classic Sudoku use?
Here is the relevant explanation: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
For a quick reminder, where should I start with Classic Sudoku?
Keep this in mind: Select an empty cell. The original clues cannot be edited.
Before I begin, do I need an account or a payment for Classic Sudoku?
The key detail is this: No player account or payment is needed. Game scores are recreational results, not cash prizes.
For my first round, how can I find Classic Sudoku again?
Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
On this playing page, how do I report an issue with Classic Sudoku?
Keep this in mind: Use the contact form and include the game name, browser, device and the actions that led to the issue. Do not send passwords or payment details.