THE PLAYBOOK · ZNLTY
How to play Diagonal Sudoku
Choose a round of Diagonal Sudoku and settle into its rules. 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. Check the relevant rule before repeating a move. Use the opening round to become familiar with the layout. 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. Use the example to check your reasoning.
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. Read that aim before choosing your first action. Take a moment to understand the current position.
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. Read the example below alongside these instructions.
A useful example
On one puzzle in this collection, row 1, column 1 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. Notice the change in the playing area.
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. Watch the feedback after an action. A message can explain whether the input was accepted or whether a rule needs attention.
Common questions
For this browser game, 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.
For a quick reminder, how do I control Diagonal 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 Diagonal 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. The two long diagonals must also contain each symbol once.
While learning, 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.
For my first round, what format does Diagonal Sudoku offer?
For clarity: Play using the solo mode shown on this page. Read the controls before starting a new round.
On this playing page, 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.