Game guide · GODIEA
Diagonal Sudoku: rules and examples
Take a moment with Diagonal Sudoku before moving to another game. 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 example below to understand a decision. Identify the playing area and the controls you need. Use the example below to understand a decision.
A small practice goal
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 purpose of your moves
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.
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.
Your inputs
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. Read the example below alongside these instructions.
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.
A mistake to avoid
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. Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart.
Questions that come up during play
What is the goal of Diagonal Sudoku?
Here is the relevant explanation: 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.
As a new player, what example helps explain Diagonal Sudoku?
Here is the relevant explanation: 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.
When I return, what should I watch out for in Diagonal Sudoku?
Keep this in mind: 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?
Play using the solo mode shown on this page. Read the controls before starting a new round.
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.
For a quick reminder, where should I start with Diagonal Sudoku?
For clarity: Select an empty cell. The original clues cannot be edited.
Do I need an account or a payment for Diagonal Sudoku?
The key detail is this: 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?
For clarity: 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.