THE PLAYBOOK · KZZDM
How to play Diagonal Sudoku
Start Diagonal Sudoku by looking at the playing area and its controls. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once. Look at what changes after your first action. Begin with the solo mode shown on the page. Use the example below to understand a decision.
Make the controls familiar
Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart. Notice the feedback after each input.
Your goal
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once. The feedback beside the game helps you follow the round. Review the board or playing area as it changes.
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. Use the control method described here for this activity. Return to the rules if the result is unexpected.
A useful example
On one puzzle in this collection, row 1, column 3 has 3 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. Choose a deliberate next step.
Watch out for this
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. Before your first action, say what you are trying to achieve. Then compare the result with the goal.
Common questions
Before I begin, what is the goal of Diagonal Sudoku?
Keep this in mind: Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once.
As a new player, how do I control Diagonal Sudoku?
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 Diagonal Sudoku?
On one puzzle in this collection, row 1, column 1 has 2 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 Diagonal Sudoku?
Here is the relevant explanation: Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
When I return, what format does Diagonal Sudoku offer?
Keep this in mind: 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 Diagonal 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.