THE PLAYBOOK · 09JB
Diagonal Sudoku: instructions and practice
Read the aim of Diagonal Sudoku, then make your first move. 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. Identify the playing area and the controls you need. Look at what changes after your first action.
A focus for your next round
After a move, check what changed. Decide which rule explains the new state before acting again. Notice the feedback after each input.
The objective of 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. An attractive position is not enough unless the goal is met. Start with a deliberate move.
A walkthrough of the rules
- 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. Look at the feedback after the action.
See the idea in action
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. Focus on why the action is allowed, not only its outcome. Notice the change in the playing area.
A useful caution
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Check the rule before repeating the action. Before your first action, say what you are trying to achieve. Then compare the result with the goal.
Questions that come up during play
Before I begin, what is the goal 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.
For my first round, 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.
When I return, what example helps explain Diagonal Sudoku?
For clarity: On one puzzle in this collection, row 1, column 1 has 5 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
For my first round, what should I watch out for in Diagonal Sudoku?
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
While learning, what format does Diagonal Sudoku offer?
Here is the relevant explanation: Play using the solo mode shown on this page. Read the controls before starting a new round.
Before I begin, which play mode does Diagonal Sudoku use?
The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
