19×19

19×19 refers to the standard board size used in the game of go (weiqi or baduk). A 19×19 board has 19 equally spaced lines in each direction, creating 361 intersections where stones may be placed. This size is the traditional and most widely used for serious play, though smaller boards exist for learning and quicker games.

Physically, boards are commonly made of wood and called goban. A typical board is roughly 45 to 60 centimeters across, with lines that are often drawn or inlaid into the surface. Stones are usually 20 to 25 millimeters in diameter, and come in black and white. Go equipment emphasizes a simple, durable aesthetic and allows long games that can last several hours.

During play, players alternately place stones on the intersections. The objective is to secure more territory than the opponent by surrounding empty points and by capturing opposing stones when they are fully surrounded and have no liberties. Captures remove stones from the board, and players must manage life and death of groups. Moves are recorded by board coordinates; columns are labeled with letters A through T (omitting I) and rows are numbered 1 to 19. The game incorporates rules such as the Ko rule, which prevents immediate repetition of a previous board position.

The 19×19 board is central to professional competition and many instructional contexts. Smaller boards, such as 9×9 and 13×13, are used for teaching or shorter games, while online platforms commonly support both 19×19 and variants.