Killer Sudoku
- Category
- Brain
- Players
- 1
- Controls
- Tap
- Grid
- 4 x 4
- Loads
- No install
Controls
| Tap a cell | Select it. |
| Tap a number | Place it. |
| Tap ✕ | Clear the cell. |
Next up
| Tap a cell | Select it. |
| Tap a number | Place it. |
| Tap ✕ | Clear the cell. |
Killer Sudoku puts arithmetic on top of the usual grid. Numbers one to four go once into every row, column and box as normal, but the grid is also carved into cages, and the numbers in each cage must add to its total.
What makes it different from ordinary sudoku is that you begin with no numbers at all. Every clue is a sum, so the first placements come from cages where only one combination is possible, and the Latin square constraints take over from there.
Look for cages with only one combination. On a four grid, a two-cell cage totalling three must be one and two, and a cage totalling seven must be three and four. Those are your openings.
Remember the Latin square rule constrains cages too. Two cells of a cage in the same row cannot hold the same number, which rules out combinations the sum alone would allow.
Use the total of a row. Every row adds to ten, so if cages covering most of a row account for eight, the remaining cell must be two.
Work outward from the smallest cages. Two-cell cages have far fewer possibilities than three-cell ones, and each one you settle constrains its whole neighbourhood.
A group of outlined cells whose numbers must add up to the total shown.
Only if the cells lie in different rows and columns, since the sudoku rule still applies.
Because the cage sums are the clues. That is what distinguishes Killer Sudoku from the ordinary version.
Yes, each is generated from a completed grid with the cage totals read off it.
Completely free, with no trial and no unlock. Killer Sudoku loads with the page and plays immediately, without an install step or a video ad first.