THE PLAYBOOK · XTTAOBAO
How to play Classic Sudoku
Use a short break to learn the rhythm 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. Treat the first round as a chance to learn the controls. Keep the game area visible while you use its controls.
Read before acting
Read one step at a time and try it on the playing area. Match the instruction to the control you use. Refer to the controls when needed.
Your goal
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. Check the rules when you are unsure.
Step by step
- 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.
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. On a smaller screen, keep the active part of the board within view. Look at the feedback after the action.
A useful example
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. Your next round may have a different position, so inspect it before acting. Verify the rule before continuing.
Watch out for this
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Read the feedback to see why an action did not have the expected result. Before your first action, say what you are trying to achieve. Then compare the result with the goal.
Common questions
When I return, 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.
What example helps explain Classic Sudoku?
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.
As a new player, what should I watch out for in Classic Sudoku?
Here is the relevant explanation: 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?
Play using the solo mode shown on this page. Read the controls before starting a new round.
For this browser game, which play mode does Classic Sudoku use?
Here is the relevant explanation: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
