Go (圍棋 or 围棋, meaning “encircling game”) was invented in ancient China more than 2,500 years ago, which may make it the oldest board game still played today. It was considered one of the four cultivated arts of the Chinese scholar gentleman, along with calligraphy, painting and playing the musical instrument guqin. The earliest written reference to the game is from the historical annal Zuo Zhuan (4th century BCE) referring to a historical event of 548 BC. It is also mentioned in Book XVII of the Analects of Confucius and in two books written by Mencius (c. 3rd century BC). In each of these works, it is referred to as yì (弈). In modern China, it is known as weiqi (圍棋or 围棋) which means “encirclement board game”. Originally played on a 17×17 line grid, by the time of the Tang Dynasty (618–907) a 19×19 grid became standard. Legend has it that the mythical Chinese emperor Yao (2337–2258 BC), was said to have had his counselor Shun design it for Danzhu, his unruly son, to influence him favorably. Theories suggest that the game came from tribal warlords, who used stones to map out attacking positions.
Sometime between the 5th and 7th centuries CE the game was introduced to Korea and was called baduk (바둑) It was popular among the higher classes. A variant of the game called Sunjang baduk was developed by the 16th century and became the main variant played in Korea until the end of the 19th century.
In the 7th century CE the game reached Japan where it is called go (碁) or igo (囲碁). Go became popular at the imperial court during the 8th century, then among the general public by the 13th century. The version of the game today was formalized in Japan during the 15th century CE. In 1603 Tokugawa Ieyasu re-established Japan’s unified national government and also assigned the best Go player in Japan, a Buddhist monk named Nikkai, to the post of Godokoro (Minister of Go). Nikkai took the name Honinbo Sansa and founded the Honinbo Go school. Other officially recognized and subsidized schools opened soon after.
Go is an easy game to play but a tough game to play well and master, even more so than chess. There are more move possibilities than the total number of atoms in the visible universe. Compared to chess, Go has both a larger board, is a much longer game, and a lot more to consider per move.
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 (“points”) of a board with a 19×19 grid of lines. Beginners often play on smaller 9×9 and 13×13 boards, and evidence shows that the game was played on a board with a 17×17 grid in earlier centuries. However, boards with a 19×19 grid had become standard by the time the game had reached Korea in the 5th century CE and later Japan in the 7th century CE.
The objective of Go is to completely surround a larger total area of the board than your opponent. Once placed on the board, stones may not be moved, but stones are removed from the board when “captured”. 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; the game has no set ending conditions beyond this. When a game concludes, the territory is counted along with captured stones and komi (points added to the score of the player with the white stones as compensation for playing second) to determine the winner. Games may also be terminated by resignation.