Game guide · JXLGGC
Diagonal Sudoku: learn through an example
Make Diagonal Sudoku your next activity in the game library. 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. Identify the playing area and the controls you need. Use the example below to understand a decision.
Bring this focus to a round
After a move, check what changed. Decide which rule explains the new state before acting again. Keep the objective visible.
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. The feedback beside the game helps you follow the round. Try to explain the aim in your own words.
Work through the instructions
- 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.
Using the playing area
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. Avoid pressing the same control repeatedly while a move is being processed.
See how the rules apply
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.
Where a round can go wrong
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Take a moment to reassess the position before continuing. Before your first action, say what you are trying to achieve. Then compare the result with the goal.
Clarifying the way this game works
While reading the Guide, 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?
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.
While learning, what example helps explain Diagonal Sudoku?
Keep this in mind: On one puzzle in this collection, row 1, column 2 has 2 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
While learning, what should I watch out for in Diagonal Sudoku?
The key detail is this: Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
While learning, what format does Diagonal Sudoku offer?
Keep this in mind: Play using the solo mode shown on this page. Read the controls before starting a new round.
For my first 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.
Before I begin, where should I start with Diagonal Sudoku?
For clarity: Select an empty cell. The original clues cannot be edited.
While learning, 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.
Before I begin, 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 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.