Game guide · XDSTMALL
Learn the rules of Classic Sudoku
Bring your attention to one round of Classic Sudoku. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Check the relevant rule before repeating a move. Check the rule that explains your first action. Check the relevant rule before repeating a move.
One thing to notice as you play
When a decision goes wrong, compare it with the common mistake described below. Start again only when you intend to leave the current round. Refer to the controls when needed.
The purpose of your moves
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. Review the board or playing area as it changes.
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.
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. Look at the feedback after the action.
An example to follow
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. Compare this with the rule that governs the move. Notice the change in the playing area.
Pay attention to this rule
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. A different version of the game may use a different rule. Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow.
If you are unsure
When I return, what is the goal of Classic Sudoku?
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?
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.
As a new player, what example helps explain Classic Sudoku?
Keep this in mind: 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.
For a quick reminder, what should I watch out for in Classic Sudoku?
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
For a quick reminder, 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.
For this browser game, which play mode does Classic Sudoku use?
Keep this in mind: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
Before I begin, where should I start with Classic Sudoku?
Keep this in mind: Select an empty cell. The original clues cannot be edited.
For this browser game, do I need an account or a payment for Classic Sudoku?
Here is the relevant explanation: No player account or payment is needed. Game scores are recreational results, not cash prizes.
How can I find Classic Sudoku again?
For clarity: Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
How do I report an issue with Classic Sudoku?
For clarity: 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.
