Game guide · SZWSXS
Classic Sudoku: instructions and practice
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. Use the example below to understand a decision. Check the rule that explains your first action. Keep the game area visible while you use its controls.
Try a more deliberate round
Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board. Make the next step deliberately.
The goal to keep in mind
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. Follow this game’s rules rather than another version’s.
How a round unfolds
- 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.
Input guidance
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.
Try this example
Before filling a cell, compare the symbols already used in its row, column and 3 × 3 region. A candidate must be absent from all three. Compare this with the rule that governs the move. Choose a deliberate next step.
Notice this detail
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. Watch the feedback after an action. A message can explain whether the input was accepted or whether a rule needs attention.
Clarifying the way this game works
For a quick reminder, what is the goal of Classic Sudoku?
Keep this in mind: Fill all cells with 1–9; do not repeat a symbol in any row, column or region.
For a quick reminder, 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.
Before I begin, what example helps explain Classic Sudoku?
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.
When I return, 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.
Before I begin, what format does Classic Sudoku offer?
Keep this in mind: Play using the solo mode shown on this page. Read the controls before starting a new round.
While reading the Guide, 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.
On this playing page, where should I start with Classic Sudoku?
For clarity: 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?
No player account or payment is needed. Game scores are recreational results, not cash prizes.
For this browser game, how can I find Classic Sudoku again?
Here is the relevant explanation: Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
While learning, 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.