About the game
Little dots between the cells: white for numbers that differ by one, black for a number and its double. Every dot is shown, so an empty border says something too.
Rules
Fill the grid so that every row, every column and every 3×3 box holds each number from 1 to 9 exactly once.
A white dot between two cells means their numbers differ by 1; a black dot means one is double the other. Every dot is shown: where there is none, neither is true. 1 and 2 can carry either dot.
Every puzzle has exactly one solution, so it can always be found by reasoning, without guessing. A number that breaks a rule turns red.
How to play
- Tap a cell, then a number below the board (or type it).
- A white dot joins numbers that differ by 1, a black dot a number and its double.
- Where there is no dot, neither is true.
- Not sure? Switch on notes and pencil in the options.
- Languages
- EN · DE
- Works on
- Phone, tablet, computer
- Players
- Just you