Put the letters from 'A' to 'D' into the fields of the diagramm. Same letters may not be horizontally or vertically adjacent. The numbers at the borders tell you the number of occurences of the corresponding letter in that row or column.
The following variants can all be combined; only "no diagonal neighbours" is of course not possible together with "hexgrid".
- Changed number of letters: The number of letters can be changed a little bit. For some of the following variants this is recommended.
- No diagonal neighbours: Additionally to the normal rules, it's also forbidden to have letters in diagonally neighbouring fields. For this variant at least five letters are needed.
- Hexgrid: Instead of a rectangular grid a hexgrid can also be used. In the hex grid rows may have different lengths and the neighbourcondition also changes.
- With black fields: More conclusions result, if you remove some of the fields (color them black).
- With incomplete information: Much of the information given at the borders are superfluous. If you drop some of them, the puzzle gets a completely new charm.
- Crypto variant: All the digits at the borders are replaced by letters and you have to find the assignment first.