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 (game)
The traditional Japanese "goban" is between thick and has legs; it sits on the floor (see picture). It is preferably made from the rare golden-tinged Kaya tree ("Torreya nucifera"), with the very best made from Kaya trees up to 700 years old. More recently, the related California Torreya ("Torreya californica") has been prized for its light color and pale rings as well as its reduced expense and more readily available stock. The natural resources of Japan have been unable to keep up with the enormous demand for the slow-growing Kaya trees; both "T. nucifera" and "T. californica" take many hundreds of years to grow to the necessary size, and they are now extremely rare, raising the price of such equipment tremendously. As Kaya trees are a protected species in Japan, they cannot be harvested until they have died. Thus, an old-growth, floor-standing Kaya "goban" can easily cost in excess of $10,000 with the highest-quality examples costing more than $60,000.