Killer Sudoku

THE PLAYBOOK · CHENXIJIXIE

Killer Sudoku: learn through an example

Make Killer Sudoku your next activity in the game library. Fill rows, columns and boxes with 1–9 once. Cage digits cannot repeat and must add to their clue. Look at what changes after your first action. Treat the first round as a chance to learn the controls. Check the relevant rule before repeating a move.

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.

A small practice goal

Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart. Make the next step deliberately.

Your goal

Fill rows, columns and boxes with 1–9 once. Cage digits cannot repeat and must add to their clue. An attractive position is not enough unless the goal is met. Return to the instructions when a step is unclear.

The order of play

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.

Choosing and moving on screen

Click or tap cells and the digit pad. Use Notes, Undo and Reveal selected. Large boards scroll inside the game. Use the control method described here for this activity. Look at the feedback after the action.

Learn from a sample situation

A two-cell cage labelled 3 holds 1 and 2; a one-cell cage fixes its own value. Compare this with the rule that governs the move. Check the stated objective.

An important reminder

A full board must obey every extra rule. Reveal supplies assistance; it is not an earned deduction. Compare the situation with the worked example. Before your first action, say what you are trying to achieve. Then compare the result with the goal.

Common questions