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RULES & PRACTICE

How to Play Diagonal Sudoku

Play Diagonal Sudoku ↗

THE PLAYBOOK · PT-BUS

How to play Diagonal Sudoku

PT-BUS presents Diagonal Sudoku with a practical playbook rather than a download screen. 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 the observe, then act note before you begin.

Observe, then act

Look at the full play area and read the status message. Make a deliberate choice and compare the outcome with your expectation.

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

  1. Select an empty cell. The original clues cannot be edited.
  2. Choose a symbol from the number pad, or type it on a keyboard.
  3. Turn Notes on to record candidate symbols without committing an answer.
  4. Use Check entries to check your filled values. Hint reveals one value from the verified solution.
  5. 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

What is included in this edition?

A real 9 × 9 puzzle with 3 × 3 regions, candidate notes, undo and saved progress. Every included puzzle is checked for a unique solution.

Which controls should I use?

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.

Can you show a concrete 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.

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