Game guide · ITCGT
Your guide to Diagonal Sudoku
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. Use the example below to understand a decision.
Practice beyond the first move
Keep the stated aim separate from side details such as animation or appearance. Progress is measured by the game’s own completion or scoring rules. Refer to the controls when needed.
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. Keep that objective in view throughout the round. Return to the instructions when a step is unclear.
Start here and follow along
- 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.
Your inputs
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. Use the control method described here for this activity. Use the visible help when you are unsure of the next input.
Put the rules into context
On one puzzle in this collection, row 1, column 3 has 3 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. Look for the relevant detail.
A mistake to avoid
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Read the feedback to see why an action did not have the expected result. When a decision goes wrong, compare it with the common mistake described below. Start again only when you intend to leave the current round.
Answers about the rules and controls
Before I begin, what is the goal of Diagonal Sudoku?
Here is the relevant explanation: 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.
While reading the Guide, 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.
On this playing page, what example helps explain Diagonal Sudoku?
Here is the relevant explanation: On one puzzle in this collection, row 1, column 5 has 3 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
Before I begin, 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.
For a quick reminder, 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.
For my first round, 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.
For my first round, where should I start with Diagonal Sudoku?
For clarity: Select an empty cell. The original clues cannot be edited.
On this playing page, do I need an account or a payment for Diagonal Sudoku?
Here is the relevant explanation: No player account or payment is needed. Game scores are recreational results, not cash prizes.
While learning, how can I find Diagonal Sudoku again?
For clarity: Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
When I return, how do I report an issue with Diagonal Sudoku?
Keep this in mind: Use the contact form and include the game name, browser, device and the actions that led to the issue. Do not send passwords or payment details.