Copyright (c) 1998 Reiner Knizia
This game is played on an empty 11x11 square board (each player has 50 stones):
Here are two examples of the 'O' pattern. White pattern with be a winning position, since it is made of 10 stones.
The top black L has 5 stones. The bottom black L has 6 stones, since the other two stones do not count on the L structure (however, the Black player could grow it to the right).
The White structure is not an L, each side must have at least 3 stones.
|X's and I
These are typical N in-a-row, with at least 4 stones.
|Counting after a
When both players find themselves in a stalemate, i.e., no one will beat the largest patterns, they should count their points. In this board, the marked stones represent the structures that get some points. Black wins 13-12, 8 points for his O and 5 for his X.
|L and I
Patters can share stones. The marked Black stone is part of an L pattern of size 6, and part of an I pattern of size 4.
You can read more details in the following webpage, namely the winning goal procedure..