Game guide · JZJSBYY
Play Classic Sudoku with the rules at hand
Choose a round of Classic Sudoku and settle into its rules. 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. Use the example below to understand a decision.
One thing to notice as you play
Read one step at a time and try it on the playing area. Match the instruction to the control you use. Use the example to check your reasoning.
The objective of a round
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. Start with a deliberate move.
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.
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. Use one clear input at a time.
See the idea in action
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. Compare this with the rule that governs the move. Look for the relevant detail.
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.
More answers before you play
As a new player, 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.
On this playing page, 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.
While reading the Guide, 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.
While learning, 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.
When I return, 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.
Before I begin, where should I start with Classic Sudoku?
Keep this in mind: Select an empty cell. The original clues cannot be edited.
While reading the Guide, 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.
Before I begin, 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.
As a new player, how do I report an issue with Classic Sudoku?
Here is the relevant explanation: 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.