Baduk is a strategic board game. It is known as Baduk in Korean, Weiqi in Chinese and Igo or Go in Japanese. Baduk originated in ancient China, centuries before its earliest known references in 5th century BC writing. It is mostly popular in East Asia but has nowadays gained some popularity in the rest of the world as well. This game is noted for being rich in strategic complexity despite its simple rules.
Baduk is played by two players alternately placing black and white stones on the vacant intersections of a line grid. The standard size of this grid is 19 × 19, although the rules of Go can be freely applied to any size: 13 × 13 and 9 × 9 are also popular choices for simpler and more tactic-oriented games as well as a way to introduce Baduk to new players.
The objective of the game is to control a larger part of the board than the opponent. To achieve this, players strive to place their stones in such a way that they cannot be captured, while mapping out territories the opponent cannot invade without being captured. A stone or a group of stones is captured and removed if it has no empty adjacent intersections, the result of being completely surrounded by stones of the opposing color.
On one hand, placing stones close together helps them avoid capture, as they can support each other and capture attacking stones before they are themselves captured. Placing stones far apart, on the other hand, influences more of the board. Part of the strategic difficulty of the game stems from finding a balance between such conflicting interests.
Players strive to serve both defensive and offensive purposes, and choose between tactical urgency and strategic plans. The game ends, and the score is counted when both players consecutively pass on a turn, indicating that neither side can increase its territory or reduce its opponent's.
Despite the fact that Baduk originated in ancient China, it is commonly known in the West by its Japanese name, Go. This stems from the fact that early Western players learned of the game from Japanese sources. As a result, many Go concepts for which there are no ready English equivalent have become known elsewhere by their Japanese names.
The Japanese word Go is linked to the Japanese reading of its Chinese name Weiqi, which roughly translates as "board game of surrounding.” In many East Asian cultures, Go was considered one of the most important skills a civilized person could learn.
Quoted Wikipedia's definition of Go.