Preparing Killer Sudoku…
How to play Killer Sudoku
Combine classic 9×9 Sudoku with cage arithmetic. Every original puzzle in this catalog has one verified solution. Dashed boundaries group cells into cages, and the small corner number gives their total. Selecting a cage shows its remaining digit combinations.
- Fill each row, column and 3×3 box with 1 through 9 exactly once.
- The digits inside a dashed cage must add up to its corner total without repeating. A one-cell cage directly identifies its digit.
- Tap a cell and use the number pad, or type a digit. Toggle Notes to record candidates. Erase and Undo let you revise a deduction.
- Use Explain hint for a single-cell deduction based on visible entries and cage sums. It does not secretly reveal the stored answer.
- Choose another catalog puzzle to resume its own saved progress. Share puzzle gives a friend the exact same cage layout.
A tip for your next game
A two-cell cage totaling 3 must contain 1 and 2. Their order depends on the crossing rows, columns and boxes. The cage panel lists combinations, not guaranteed positions.
Common questions
Is every puzzle uniquely solvable?
Yes. The original published catalog is checked for valid Sudoku solutions, connected cages, correct sums and exactly one solution. Uniqueness does not promise a particular human difficulty.
Are notes and saves shared with classic Sudoku?
No. Killer keeps separate versioned progress for every catalog puzzle. Classic 4×4, 6×6, 9×9 and 16×16 saves keep their existing behavior.
Why is an entry marked as a conflict?
It repeats a digit in a row, column, box or cage, or makes the cage sum impossible. A locally valid entry is not necessarily the final correct answer.