Game guide · RCFUTURE11
Diagonal Sudoku: how a round works
Open Diagonal Sudoku, check the instructions and begin a round. 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. Identify the playing area and the controls you need. Keep the game area visible while you use its controls.
Practice beyond the first move
Before your first action, say what you are trying to achieve. Then compare the result with the goal. Refer to the controls when needed.
Understand the aim
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. Return to the instructions when a step is unclear.
The order of play
- 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.
Input guidance
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. Use one clear input at a time.
Try this 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. Apply the same reasoning to the position in your own round. Take a moment to compare.
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. When a decision goes wrong, compare it with the common mistake described below. Start again only when you intend to leave the current round.
Read these answers for extra help
On this playing page, 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.
While reading the Guide, how do I control Diagonal Sudoku?
Here is the relevant explanation: 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.
When I return, what should I watch out for in Diagonal Sudoku?
For clarity: 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?
Here is the relevant explanation: Play using the solo mode shown on this page. Read the controls before starting a new round.
When I return, which play mode does Diagonal Sudoku use?
Keep this in mind: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
As a new player, where should I start with Diagonal Sudoku?
Here is the relevant explanation: Select an empty cell. The original clues cannot be edited.
For a quick reminder, do I need an account or a payment for Diagonal Sudoku?
Here is the relevant explanation: No player account or payment is needed. Game scores are recreational results, not cash prizes.
On this playing page, how can I find Diagonal Sudoku again?
Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
For my first round, how do I report an issue with Diagonal Sudoku?
For clarity: Use the contact form and include the game name, browser, device and the actions that led to the issue. Do not send passwords or payment details.
