THE PLAYBOOK · YINGONG123
How to play Diagonal Sudoku
Choose Diagonal Sudoku at YINGONG123 for a browser session with its rules close at hand. The aim is straightforward: 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. This edition highlights careful restarts.
Careful restarts
Start a fresh round when you want another attempt. Restarting may discard current progress; read the controls rather than assuming an account backup exists.
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.
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.
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.
Watch out for this
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
Common questions
How does this round end?
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.
Can I play without an account?
Yes. This game runs in your browser without an account or a payment. There are no cash prizes.
How do I start over?
Use the New round, New puzzle or Start again control above the playing area. Starting again clears the current round.
