Copyright (c) Christian Freeling

The game starts at an empty 10x10 hexagonal board:

MOVE - Players move in turn to place one stone on an empty cell. White moves first.
GOAL - The game is won by the first player to complete a ring or a bridge or a fork. All of these are ``chains'' - closed connections of one color.
A ring is a chain around at least one cell.
A bridge is a chain linking two corners.
A fork is a chain linking three sides. Corners do not belong to sides.
An example

White can win if he plays at [1], since Black cannot avoid the double ring threat.

You can also play and read extensive information about the game at the MindSports Arena.