The Goal of Go
The object of go is to enlarge your territory at your opponent’s expense. One way is by surrounding your opponent’s stones by putting your own stones on the adjacent points, which are known as “liberties.” Once surrounded, stones are removed from the board and become your prisoners, each worth a point.
Another way to claim territory is by surrounding empty space—that is, unoccupied intersections, each of which is also worth a point. here, for instance, the two groups in the corner each enclose nine spaces, worth as many points. Obviously, it takes fewer stones to enclose territory at the corners than in the middle of the board.