The Hadoku Rules (continued)


Cells with a 1 must have one or more cells in between. Cells with a 3 must have three cells in between, cells with a 4 must have four cells in between and so on.

The rest is like Sudoku: fill each area with numbers from 1 to the size of the area. No number can be twice in the same area.

We only publish puzzles with a single solution. Some advanced solution techniques make use of this.

Learn how to play or look at all solution techniques or try our detailed walk-throughs:

Walk-through of a medium hard puzzle

Walk-through of a hard (level 4) puzzle

Walk-through of a very hard (level 8) puzzle