THE PLAYBOOK · ZCFYD
Diagonal Sudoku: how a round works
Bring your attention to one round of Diagonal Sudoku. 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. Keep the game area visible while you use its controls. Use the opening round to become familiar with the layout. Keep the game area visible while you use its controls.
Bring this focus to a round
Keep the stated aim separate from side details such as animation or appearance. Progress is measured by the game’s own completion or scoring rules. Notice the feedback after each input.
What counts as success
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. Use the instructions to see which actions move you towards it. Start with a deliberate move.
Start here and follow along
- 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.
How your actions work
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. A new-round button replaces the current round.
One way to understand the rules
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. Focus on why the action is allowed, not only its outcome. Verify the rule before continuing.
Where a round can go wrong
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. Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow.
Clarifying the way this game works
When I return, what is the goal of Diagonal Sudoku?
The key detail is this: 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.
On this playing page, how do I control Diagonal 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.
What example helps explain Diagonal Sudoku?
Here is the relevant explanation: 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.
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.
On this playing page, 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.
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.