How to Play Killer Sudoku

THE PLAYBOOK · FEINA365

How to play Killer Sudoku

Try Killer Sudoku at your own pace and keep its objective in view. Fill rows, columns and boxes with 1–9 once. Cage digits cannot repeat and must add to their clue. Keep the game area visible while you use its controls. Identify the playing area and the controls you need. Use the example below to understand a decision.

This collection contains 8 puzzles. Progress is saved in this browser. The same puzzle can appear again; the collection is not labelled with calibrated difficulty levels.

Try a deliberate move

After a move, check what changed. Decide which rule explains the new state before acting again. Keep the objective visible.

Your goal

Fill rows, columns and boxes with 1–9 once. Cage digits cannot repeat and must add to their clue. Keep that objective in view throughout the round. Review the board or playing area as it changes.

Step by step

1. Select an editable cell.
2. Enter a value using the keypad or keyboard; Notes stores candidates.
3. Read the region, cage, arrow or outside clues alongside the normal constraints.
4. Check entries verifies the completed board; Undo reverses your last input.
5. New puzzle selects another included puzzle.

Controls

Click or tap cells and the digit pad. Use Notes, Undo and Reveal selected. Large boards scroll inside the game. Keep the playing area visible while using these controls. Make sure you are interacting with the game rather than the surrounding page.

A useful example

A two-cell cage labelled 3 holds 1 and 2; a one-cell cage fixes its own value. Apply the same reasoning to the position in your own round. Choose a deliberate next step.

Watch out for this

A full board must obey every extra rule. Reveal supplies assistance; it is not an earned deduction. Take a moment to reassess the position before continuing. Read one step at a time and try it on the playing area. Match the instruction to the control you use.

Common questions