The game is played between two people on a 19x19 grid. Both aim to be the first to create a line of at least six stones, orthogonally or diagonally. Black goes first and starts by placing one stone. Thereafter both players place two stones on each of their moves. The 1-2-2-2... sequence of placements ensures that Black has no first move advantage.
There is no capture.
There is no passing of moves.
There are no restrictions where you may move.
Draws are a possibility. Neither player may be able to create a six.