How to play
Fill each row, column, and 3×3 box with 1–9 without repeats. Additionally, each dotted cage's digits must sum to the small number in its corner, and no digit may repeat inside a cage.
Strategy essentials
Learn the "45 rule" (each row, column, and box sums to 45), unique cage combinations (a 3-cell cage summing to 6 must be {1,2,3}), and innies/outies. Full walkthroughs in our Killer Sudoku guide.
FAQ
What is Killer Sudoku?
Killer Sudoku combines classic Sudoku rules with cage sums. The 9×9 grid is split into dotted cages, and every cage's digits must sum to the number in its corner without repeating.
How is Killer Sudoku different from regular Sudoku?
Regular Sudoku starts with given digits. Killer Sudoku starts with cage sums instead — you deduce every digit from the sums plus normal Sudoku rules.
Is Killer Sudoku harder than regular Sudoku?
Killer adds arithmetic to logic, so it feels harder at first. Once you learn cage combinations, it's often faster than an equivalent evil puzzle.