Range Puzzle Online

Place black squares so each numbered square can see exactly that many white squares in total. Count the numbered square itself, then look up, down, left, and right until a black square or the edge of the board blocks the view. Black squares may not touch horizontally or vertically, and the white squares must stay connected.

Place black squares to limit the visible distance from each numbered cell.

Left-click to mark a square black. Right-click to add a dot meaning the square is definitely not black. Repeated clicks cycle between black, dotted, and blank. Enter acts like left-click, and Space acts like right-click.

These puzzles reward careful deduction more than speed. Start with the most constrained clues, eliminate impossible choices step by step, and avoid guessing unless the puzzle specifically calls for it.

For the full original rules, examples, and advanced options, read Simon Tatham's official manual.