Game guide · ZJJ-HC
Making your first moves in Classic Sudoku
Read the aim of Classic Sudoku, then make your first move. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Look at what changes after your first action. Check the rule that explains your first action. Use the example below to understand a decision.
Something to practise
Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow. Use the example to check your reasoning.
What you are aiming for
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. Try to explain the aim in your own words.
Follow these playing steps
- 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.
Choosing and moving on screen
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. Use the control method described here for this activity. Read the example below alongside these instructions.
An example to follow
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. Focus on why the action is allowed, not only its outcome. Notice the change in the playing area.
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. When a decision goes wrong, compare it with the common mistake described below. Start again only when you intend to leave the current round.
More answers before you play
As a new player, what is the goal of Classic Sudoku?
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?
Keep this in mind: 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.
On this playing page, 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.
When I return, 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.
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.
While learning, where should I start with Classic Sudoku?
Here is the relevant explanation: Select an empty cell. The original clues cannot be edited.
When I return, 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.
When I return, 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.
For a quick reminder, 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.