How to Play
Killer Sudoku follows standard Sudoku rules: each row, column, and 3x3 box must contain 1-9 exactly once. In addition, dotted cages each have a sum clue. The digits in each cage must add up to that sum, and no digit repeats within a cage.
The cages replace many of the starting digits found in regular Sudoku. You must use the sum constraints to figure out which digits belong where.
Controls
Click a cell and type a digit. Pencil marks and cage-sum reminders are usually shown.
Scoring
Time and accuracy are scored. Killer Sudoku often takes longer than classic Sudoku.
