Go is an ancient board game for two players that originated in China more than 2,000 years ago. The game is noted for being rich in strategy despite its relatively simple rules.

The game is played by two players who alternately place black and white stones on the vacant intersections of a grid of 19 x 19 lines. Other board sizes are possible; beginners often start out on a 9 x 9 board. The stones act as markers, representing one’s occupation of a particular point. Once placed on the board the stones cannot be moved. The object of the game is to use one’s stones to surround and control a larger part of the board than the opponent. This can include capturing or killing the opponent’s stones, although that is not the main purpose. Captured stones are removed from the board immediately. Other dead stones are removed by agreement at the end of the game.

When a game concludes, the controlled points (or surrounded points minus prisoners) are counted to determine who has the most territory. A game can also end by resignation, when a player falls too far behind to catch up.