Go (game)
Two players, "Black" and "White", take turns placing a "stone" (game piece) of their own color on a vacant "point" (intersection) of the grid on a Go board. Black plays first. If there is a large difference in skill between the players, the weaker player typically uses Black and is allowed to place two or more stones on the board to compensate for the difference (see Go handicaps). The official grid comprises 19×19 lines, though the rules can be applied to any grid size. 13×13 and 9×9 boards are popular choices to teach beginners, or for playing quick games. Once placed, a stone may not be moved to a different point.
Go strategy and tactics
A fundamental Go strategy involves keeping stones connected. Connecting a group with one eye to another one-eyed group makes them live together. Connecting individual stones into a single group results in an increase of liberties; for instance, a single stone played in the center of the board has four liberties, while two adjacent stones in the center of the board form a unit with six; to capture the unit, an opponent would have to play stones on all of its liberties. Thus connected stones are stronger because they share their liberties. (While two separate stones have a total of up to eight liberties, they can be captured separately from one another.)