THE PLAYBOOK · HONGYIWEN
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. Check the relevant rule before repeating a move. Check the rule that explains your first action. Check the relevant rule before repeating a move.
Notice the feedback
Watch the feedback after an action. A message can explain whether the input was accepted or whether a rule needs attention. Make the next step deliberately.
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. Follow this game’s rules rather than another version’s.
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. A careful first action helps you become familiar with the layout. Make sure you are interacting with the game rather than the surrounding page.
A useful example
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. 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. After a move, check what changed. Decide which rule explains the new state before acting again.
Common questions
For my first round, what is the goal of Diagonal Sudoku?
For clarity: 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 this browser game, how do I control Diagonal Sudoku?
The key detail is this: 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?
The key detail is this: 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.
As a new player, what should I watch out for in Diagonal Sudoku?
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
As a new player, what format does Diagonal 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 learning, which play mode does Diagonal Sudoku use?
For clarity: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.