Game guide · 2COPE
Diagonal Sudoku: a guide for your next round
Use a short break to learn the rhythm 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. Look at what changes after your first action. Identify the playing area and the controls you need. Use the example below to understand a decision.
Something to practise
Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow. Notice the feedback after each input.
The goal to keep 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. Use the instructions to see which actions move you towards it. Try to explain the aim in your own words.
How a round unfolds
- 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. Use the control method described here for this activity. Contact us with the game and device if a control does not respond.
Try this example
On one puzzle in this collection, row 1, column 1 has 1 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Apply the same reasoning to the position in your own round. Verify the rule before continuing.
Avoid this misunderstanding
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. Read one step at a time and try it on the playing area. Match the instruction to the control you use.
Answers about the rules and controls
While reading the Guide, 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 my first round, 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.
While learning, 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.
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 reading the Guide, which play mode does Diagonal Sudoku use?
The key detail is this: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
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?
Keep this in mind: No player account or payment is needed. Game scores are recreational results, not cash prizes.
While reading the Guide, how can I find Diagonal Sudoku again?
The key detail is this: Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
For this browser game, 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.
