- Killer Sudoku is played on a grid, similar to traditional Sudoku.
- The grid is divided into cages, which are outlined by bold lines.
- Each cage has a target number, indicated by a number in the top corner of the cage
- The objective is to fill in the empty cells with numbers, so that each row, column, and box contains every number exactly once.
- Additionally, the numbers within each cage must add up to the target number without repeating any digits.
- Numbers can be repeated within a row, column, or box, as long as they are not in the same cage.
- Some cells may be given as clues to start the puzzle.