
Go (also known as weiqi [wei-ch'i] in Chinese and paduk in Korean) is the world's oldest and most complex strategy game.
Using round black and white counters (called 'stones') on a 19x19-line board,
each of the two players tries to surround a larger share of the territory while avoiding being surrounded by the opponent's stones.
The few, simple rules can be learned in a matter of minutes, but a lifetime is not long enough to master the game.
You can visit Sensei's Library to learn the basic rules of Go or check out Wikipedia.
The American Go Association has also published "The Way To Go" - a short Go instructional manual explaining basic rules, techniques and terminology.