Game guide · BDPSFJS
Classic Sudoku: rules and examples
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. Keep the game area visible while you use its controls. Check the rule that explains your first action. Keep the game area visible while you use its controls.
Take a closer look while playing
After a move, check what changed. Decide which rule explains the new state before acting again. Keep the objective visible.
What counts as success
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. An attractive position is not enough unless the goal is met. Try to explain the aim in your own words.
The playing sequence
- 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.
How to interact with the game
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. Check any mode label before starting.
One way to understand the rules
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. Apply the same reasoning to the position in your own round. Take a moment to compare.
A common point of confusion
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Check the rule before repeating the action. Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board.
Questions about this game
For a quick reminder, what is the goal of Classic Sudoku?
For clarity: Fill all cells with 1–9; do not repeat a symbol in any row, column or region.
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.
While learning, what example helps explain Classic Sudoku?
On one puzzle in this collection, row 1, column 1 has 1 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?
Keep this in mind: 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.
While reading the Guide, which play mode does Classic Sudoku use?
The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
For this browser game, where should I start with Classic Sudoku?
Here is the relevant explanation: Select an empty cell. The original clues cannot be edited.
For my first round, 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.
As a new player, 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.
On this playing page, 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.