The game is played on a 6x6 board which is divided into 9 2x2 squares. On these, tiles are placed which have numbers 1-6 or are empty. One side is white, the other black. The two players take turn placing the tiles which have to connect to other tiles of their color and have to fit into the rows and columns sudoku-style. The aim is to fill as many rows, columns and squares with one's own color. There are some other variants of the game in which other player's tiles can be enclosed and turned around (to one's own side), for example.