Copyright (c) 1998 Reiner Knizia

This game is played on an empty 11x11 square board (each player has 50 stones):

TURNS - At each turn, each player drops one of his stones into an empty cell.
PATTERNS - Each player must try to make these following patterns:
An O, i.e., a rectangle, with at least two stones long and two stones wide. The rectangle may be hollow, or filled with stones of either colour. Having your own interior stones, however, increases the pattern value
A L, i.e., a set of line up stones, making a right angle, with at least 3 stones on each length (no diagonals allowed).
An I, i.e., a set of vertical or horizontal adjacent stones, with at least 4 stones.
A X, i.e., a set of diagonal adjacent stones (?), with at least 4 stones.
GOAL - Wins the player that achieves one of the following conditions:
Make an O with 10 stones,
Make a L with 9 stones,
Make an I with 8 stones,
Make a X with 8 stones, or
Wins the player with more points, if none of the above patterns are achieved. Only the largest of each pattern is counted, and receives one point for each stone in the structure.
Tw'O' examples

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 stalemate

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..