Go is an abstract strategy board game for two players, in which the aim is to surround more territory than the opponent. The game was invented in ancient China more than 2,500 years ago and it was considered one of the four essential arts of the cultured aristocratic Chinese scholar caste in antiquity. The earliest written reference to the game is recognized as the historical annal Zuo Zhuan. The modern game of Go as we know it was formalized in Japan in the 15th century CE, despite its relatively simple rules, Go is very complex, even more so than chess, and possesses more possibilities than the total number of atoms in the visible universe. Compared to chess, Go has both a board with more scope for play and longer games, and, on average. The playing pieces are called stones, one player uses the white stones and the other, black. The players take turns placing the stones on the vacant intersections of a board with a 19×19 grid of lines, beginners often play on smaller 9×9 and 13×13 boards, and archaeological evidence shows that the game was played in earlier centuries on a board with a 17×17 grid. However, boards with a 19×19 grid had become standard by the time the game had reached Korea in the 5th century CE, the objective of Go—as the translation of its name implies—is to fully surround a larger total area of the board than the opponent. Once placed on the board, stones may not be moved, capture happens when a stone or group of stones is surrounded by opposing stones on all orthogonally-adjacent points. The game proceeds until neither player wishes to make another move, when a game concludes, the territory is counted along with captured stones and komi to determine the winner. Games may also be terminated by resignation, as of mid-2008, there were well over 40 million Go players worldwide, the overwhelming majority of them living in East Asia. As of December 2015, the International Go Federation has a total of 75 member countries, Go is an adversarial game with the objective of surrounding a larger total area of the board with ones stones than the opponent. As the game progresses, the players position stones on the board to map out formations, contests between opposing formations are often extremely complex and may result in the expansion, reduction, or wholesale capture and loss of formation stones. A basic principle of Go is that a group of stones must have at least one liberty to remain on the board, a liberty is an open point bordering the group. An enclosed liberty is called an eye, and a group of stones with two or more eyes is said to be unconditionally alive, such groups cannot be captured, even if surrounded. A group with one eye or no eyes is dead and cannot resist eventual capture, the general strategy is to expand ones territory, attack the opponents weak groups, and always stay mindful of the life status of ones own groups. The liberties of groups are countable, situations where mutually opposing groups must capture each other or die are called capturing races, or semeai. In a capturing race, the group with more liberties will ultimately be able to capture the opponents stones, capturing races and the elements of life or death are the primary challenges of Go
Image: Floor Goban
19x19 Go Board from Sui Dynasty
Woman Playing Go (Tang Dynasty c. 744), discovered at the Astana Graves
Korean couple, in traditional dress, play in a photograph dated between 1910 and 1920.