- Blacken some cells of the grid [on paper] or color the
gray cells of the grid either black or white [interactively].
- Cells with numbers are always white. The numbers indicate
how many of the
orthogonally and diagonally adjacent cells are black: Each number
indicates a group of orthogonally adjacent black cells; different groups are
separated by at least one white cell. Position and sequence of the clue
numbers is irrelevant.
- A question mark indicates "any number" greater than zero.
- All black cells must form an
orthogonally-connected area.
- The black cells must not cover an area of 2x2 cells or
larger.
Destiller: Clues of four puzzles are given in one grid. Distribute
the clues to four grids and solve each puzzle. The cells with clues do not
overlap, each clue cell should be fully visible in one grid only.