How to play
Fill the grid so that every row, column and 3×3 box contains the digits 1 to 9 once, just like sudoku. Instead of printed digits you get cages: the dashed shapes. The digits in a cage add up to the small number in its corner, and no digit repeats inside a cage.
Every killer sudoku on PuzzleSheets has exactly one solution, checked by a solver, and you can always reach it by logic.
Difficulty
- Easy: small cages and a few starting digits. Cage combinations and hidden singles are enough.
- Medium: needs the 45 rule (innies and outies, see the tips below).
- Hard: also needs locked candidates or pairs, the classic sudoku techniques.
- Expert: bigger cages and no starting digits. Expect to combine everything.
Tips
- Learn the unique combinations. A cage of 3 in two cells must be 1 + 2, and 4 in two cells must be 1 + 3. 16 in two cells is 7 + 9, 17 is 8 + 9. 6 in three cells is 1 + 2 + 3, and 24 in three cells is 7 + 8 + 9.
- Use the 45 rule. Every row, column and box adds up to 45. Add up the cages that lie completely inside a box: the few cells left over (the innies) must make up the difference. Cells of cages sticking out of the box (the outies) work the same way.
- A cage inside one box or line claims its digits. If a cage has to contain a 9, no other cell in that box or line can be 9.
- Use notes. Pencil in the possible digits of a cage and cross them off as the grid fills up.
Using the player
- Tap a cell, then a number. Use Notes for pencil marks.
- Highlight conflicts shows repeated digits, and cages whose digits add up wrong.
- Your progress is saved on this device. Save code / Continue later lets you carry on elsewhere.
Printing
Print 1, 2 or 4 puzzles per page on A4 or US Letter, with an optional answer key.