Gomoku is a popular game among young and old in Japan. Played on a Go board ,which is a grid of 19 lines by 19 lines. The playing area for Gomoku is only 13 by 13 so if you do not want to make a custom Gomoku board just ignore the three intersections on the outside edge of a regular Go board.
A 13 X 13 Go board
White and black Go stones
How to play
The players take turns placing a stone of their color on an intersection of the Go board.
The person playing black plays first.
Once they are placed they can not be moved.
The first player to make an unbroken line of exactly fives stones horizontally, vertically, or diagonally wins.
More then five stones in row is called an overline, and does not win.
It probably will not take long to figure out that the person playing black has the advantage in Gomoku. To fix this the problem the game Renju was invented. It is played like Gomoku but with these differences.
1. It is played on a 15 X 15 Go board.
2. To start the game one player places a black stone on the center intersection of the board and a white stone on one of the eight intersections surrounding the black stone. The same player puts a second black stone on a point no more than two intersections away from the first black stone.. See the photo below for a example of a opening move.
Next the other player decides if the want to play white or black. The white player then places one white stone anywhere on the board. Afterwards black player places two black stones anywhere on the board. The White player then removes one of the last two Black stones before taking their next turn. Players then take turns placing one stone of their color on the board. The first player to make an unbroken line of fives stones horizontally, vertically, or diagonally wins
3. There are two restrictions for the person playing black.
The first is black can not in one move make two open-ended rows of three or two open ended rows of four. To demonstrate this in the photo below black could not place a stone where the yellow chip marked A,B,or C is placed.
The second is black can not make a row of six or more stones in a row. In the photo below black can not place a stone where the D chip is placed because it would make a line of six or more stones in a row. White does not have these restrictions and can win by making a row of five or more stones or forcing black to make an illegal move.
The restrictions on black and the equalizing opening make Renju a more fair and complex variation of Gomoku. In fact it has a strong enough following to host it’s own world championship. So find yourself a board and give it a try.