The Doppit Almanac · No. 25

Sightit, a daily Kuromasu puzzle

Shade so each number sees its count

What it is

Sightit is Doppit's take on Kuromasu, the shading puzzle also known as Kurodoko. Some cells carry numbers. You shade other cells black so that each number sees exactly its own count of cells, looking out in four straight lines until a shaded cell or the board edge stops the view.

The catch that trips everyone: a number counts its own cell. A 3 sees itself and two more, not three more. Shaded cells never touch side by side, and the cells you leave open must all stay joined in one region.

How it plays

• Each number equals what its cell sees along the four directions, itself included.
• A shaded cell or the edge stops a line of sight.
• Numbers are never shaded.
• No two shaded cells touch side by side. Corners are fine.
• Every unshaded cell stays connected in one region.

The difficulties

Three boards are set daily. Easy is a five by five, solved in thirty seconds to a minute. Medium is a seven by seven, one to three minutes. Hard is a nine by nine, three to six. Expert is the same nine by nine, and it opens a step no daily board has ever used: suppose one cell is shaded, play the forced moves out, and see which rule breaks. Every expert board wants that step twice at least, on top of a deep count that clears hard's own top tenth. No daily board is ever expert. A new board every day, and it costs nothing.

Nearby in the almanac: Islandit, Lightit and Sandit