Game guide · CQXINXING
Classic Sudoku: rules and examples
Classic Sudoku gives you a focused activity to play in your browser. 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.
An idea for your next attempt
Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board. Notice the feedback after each input.
What you are aiming for
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The feedback beside the game helps you follow the round. Try to explain the aim in your own words.
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.
Keyboard and screen 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. Keep the playing area visible while using these controls. A new-round button replaces the current round.
Learn from a sample situation
On one puzzle in this collection, row 1, column 1 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. Keep the game’s format in mind.
A mistake to avoid
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. Before your first action, say what you are trying to achieve. Then compare the result with the goal.
Questions that come up during play
For a quick reminder, what is the goal of Classic Sudoku?
The key detail is this: Fill all cells with 1–9; do not repeat a symbol in any row, column or region.
For this browser game, how do I control Classic Sudoku?
Here is the relevant explanation: 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 my first round, what example helps explain Classic Sudoku?
Here is the relevant explanation: On one puzzle in this collection, row 1, column 1 has 8 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
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 this browser game, 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.
Before I begin, which play mode does Classic Sudoku use?
For clarity: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
For my first round, where should I start with Classic Sudoku?
Select an empty cell. The original clues cannot be edited.
For a quick reminder, do I need an account or a payment for Classic Sudoku?
Keep this in mind: No player account or payment is needed. Game scores are recreational results, not cash prizes.
Before I begin, 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.
While learning, how do I report an issue with Classic Sudoku?
The key detail is this: 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.