0hn0

What is it?

0h n0 is a little logic game by Martin Kool (Q42), made as a complement to 0h h1 and inspired by the Japanese puzzle Kuromasu. Blue dots can see others in their own row and column—they see at least one—and their numbers tell how many. Red dots block their view.

How to play

• Open the site and choose a board size
• Place blue and red dots so every blue number matches how many dots it can see
• Use the hint icon and settings (timer, theme, language) if you need them
• Optional sign-in unlocks achievements and leaderboards on supported clients