THE PLAYBOOK · XTTAOBAO
How to play Diagonal Sudoku
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. Choose a clear next step rather than rushing through the instructions. Identify the playing area and the controls you need. Choose a clear next step rather than rushing through the instructions.
Try a deliberate move
After a move, check what changed. Decide which rule explains the new state before acting again. Refer to the controls when needed.
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. Keep that objective in view throughout the round. Follow this game’s rules rather than another version’s.
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. Read a button’s label before selecting it. Use the visible help when you are unsure of the next input.
A useful example
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. Use the example as a guide rather than a substitute for reading your board. Check the stated objective.
Watch out for this
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. Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart.
Common questions
What is the goal of Diagonal Sudoku?
Keep this 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.
As a new player, 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.
While learning, what example helps explain Diagonal Sudoku?
For clarity: 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 reading the Guide, 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?
Keep this in mind: 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.