Nonogram

A Nonogram is a logic puzzle where solvers color or leave blank grid cells based on numbers at the side of the grid to reveal a hidden picture. They are also widely known as Picross, Hanjie, or Griddlers.

Players use logic to determine which cells must be filled or left blank by looking at the numerical clues, which indicate the runs of marked squares in each row and column. Once a row and column are solved correctly, the shaded cells form a pixel-art image.

Nintendo popularized the format in the West with its "Picross" series, starting with "Mario's Picross" on the Game Boy in 1995. There are also hundreds of mobile apps and PC games dedicated to the mechanic today.

The puzzle was independently invented by Japanese designers Non Ishida and Tetsuya Nishio in the late 1980s. Non Ishida originally won a design competition in 1987 by lighting up windows in a skyscraper to form a picture, which inspired the grid format.