Range

Range challenges you to place black “blocker” squares on a grid so that each numbered cell can “see” exactly as many unobstructed cells (including itself) as its number indicates—horizontally and vertically, but not diagonally.

Visibility extends in the four cardinal directions until blocked by a black square or the edge of the grid. For example, a cell marked “5” must have a total of five visible cells in its row and column combined (counting itself), with black squares positioned to ensure it doesn’t see more—or fewer—than that. Crucially, black squares cannot be placed on numbered cells, and they serve only as obstacles to control sightlines.

What makes Range especially satisfying is how it blends spatial reasoning with arithmetic constraints. Every black square you place affects the visibility of multiple numbered cells at once, creating a tightly interwoven web of logic. The puzzle is always uniquely solvable through deduction alone—no guessing required.

Perfect for fans of Light Up (Akari), Battleships, or Sudoku, Range offers a fresh take on visibility-based logic with elegant, minimalist rules.

Place black squares, so as to meet the following conditions:

• No two black squares are orthogonally adjacent.
• No group of white squares is separated from the rest of the grid by black squares.
• Each numbered cell can see precisely that many white squares in total by looking in all four orthogonal directions, counting itself. (Black squares block the view. So, for example, a 2 clue must be adjacent to three black squares or grid edges, and in the fourth direction there must be one white square and then a black one beyond it.)

Left-click to colour a square black. Right-click to mark a square with a dot, if you know it should not be black.