To correct this, we have our second game idea. The first time two diagonally opposite corners of a square tile are occupied by stones of the same color, a diagonal line connecting them is drawn. However, only one diagonal line may be drawn in each square. This provides a blocking mechanism. Note that in the following example game, X never appears in any square, because it is not allowed.
Paths consist only of the vertical and horizontal line segments.
Diagonally opposite corners of a square tile are never directly joined. The winner is the first player to achieve his goal, and exactly one player will win. Put another way, the goal in the following games is not to construct a path joining your two sides of the board, but rather to prevent your opponent from constructing a path joining his two sides of the board. The following game is defective, and we shall remedy this afterward. There seems to be no way for a player to defend against his opponent's moves.