THE PLAYBOOK · RUIQIWJ
How to play Diagonal Sudoku
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. Check the relevant rule before repeating a move. Choose a comfortable screen position before beginning. Use the example below to understand a decision.
Focus on one rule
Choose one rule to keep in mind for this round. Apply it consistently rather than guessing what another version might allow. Use the example to check your reasoning.
Your goal
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. Try to explain the aim in your own words.
Step by step
- 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.
Controls
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. Check any mode label before starting.
A useful 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. Focus on why the action is allowed, not only its outcome. Notice the change in the playing area.
Watch out for this
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. 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.
Common questions
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.
As a new player, 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.
On this playing page, what example helps explain Diagonal Sudoku?
Keep this in mind: On one puzzle in this collection, row 1, column 5 has 3 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
For a quick reminder, 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.
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.
For a quick reminder, which play mode does Diagonal Sudoku use?
For clarity: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
