THE PLAYBOOK · COEYSHOES
Diagonal Sudoku: instructions and practice
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. Look at what changes after your first action. Read the objective before making your first input. Check the relevant rule before repeating a move.
Practice with a purpose
When a decision goes wrong, compare it with the common mistake described below. Start again only when you intend to leave the current round. Use the example to check your reasoning.
Understand the aim
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. Start with a deliberate move.
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.
Making selections and moves
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. Return to the rules if the result is unexpected.
Try this example
On one puzzle in this collection, row 1, column 1 has 2 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Compare this with the rule that governs the move. Choose a deliberate next step.
Avoid this misunderstanding
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. Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board.
Game-specific help
On this playing page, what is the goal of Diagonal Sudoku?
For clarity: 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.
When I return, 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.
For a quick reminder, what example helps explain Diagonal Sudoku?
Keep this in mind: On one puzzle in this collection, row 1, column 3 has 1 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
For this browser game, 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.
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.
For this browser game, 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.