Go is an ancient two-player abstract strategy board game that originated in China over 2,500 years ago. It is played on a grid of black lines, typically 19x19 in size (though smaller boards like 13x13 or 9x9 are used for beginners or quicker games). The equipment consists of black and white lens-shaped pieces called "stones," which are placed one at a time on the intersections of the lines.

The objective is to control more territory than your opponent by using your stones to surround empty areas of the board, as well as to capture enemy stones by completely surrounding them. Despite its simple rules—alternating turns, placing stones, and the prohibition of suicide moves (a move that would cause a group to be immediately captured)—the game is profoundly complex. It is celebrated for its immense strategic depth, balance between territorial and positional play, and emphasis on intuition, pattern recognition, and long-term planning over pure calculation.

The game ends when both players consecutively pass, indicating that no more beneficial moves remain. The score is then calculated by counting each player's surrounded territory plus the number of captured stones. The player with the higher score wins.

Go is revered not just as a competitive game but also as an art form, a discipline for mental development, and a cultural artifact reflecting philosophical concepts like balance, flexibility, and influence. Today, it is played worldwide, with professional systems in several East Asian countries and advanced computer programs like AlphaGo having achieved superhuman mastery.