THE PLAYBOOK · QINSMAN
How to play Diagonal Sudoku
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. Choose a clear next step rather than rushing through the instructions. Check the rule that explains your first action. Choose a clear next step rather than rushing through the instructions.
A useful comparison
Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board. 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. The feedback beside the game helps you follow the round. 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. On a smaller screen, keep the active part of the board within view. A new-round button replaces the current round.
A useful example
On one puzzle in this collection, row 1, column 1 has 3 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Use the example as a guide rather than a substitute for reading your board. Read the matching step again.
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. After a move, check what changed. Decide which rule explains the new state before acting again.
Common questions
Before I begin, 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.
How do I control Diagonal Sudoku?
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.
For this browser game, 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.
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.
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 a quick reminder, 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.