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.
Dunhuang Go Manual
The fourth section (像名弟四) discusses the symbolism of the Go board and the symbolic names given to different positions on the board. For example, the author states that "Go stones are round in imitation of the heavens, and the Go board is square in the same way that the earth is; that there are 361 intersections on the board reflects the division of the ecliptic [into 365 days]" (碁子圓以法天，碁局方以類地。碁有三百六十一道，倣周天之道數). The explicit mention here that a Go board has 361 points indicates that the author of the manual was familiar with the standard board with a 19 × 19 grid, and not the earlier 17 × 17 grid board that is attested in archaeological evidence dating back to the late Han Dynasty (206 BCE – 220 CE) and from paintings dating up to the mid 8th century.