Users manual - History and rules

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The two basic rules of Renju, Gomoku, and all five-in-a-row games

Rule 1. Play alternates between one player who starts the game (called Black because he is playing with black stones) and another player (usually called White because he is playing with white stones). The board usually has the limits of 15x15 intersections but long ago the board had the same size as the Go-board i.e. it had 19x19 intersections. It is also possible to play writing crosses and circles in the squares of a piece of paper (usually a paper made for mathematical calculations) and then the ground to play on has virtually no limits because it is possible to add a new paper to the first and make it infinite. Of course it is only possible to put the mark or the stone on an empty place.

Rule 2. The first player to get an unbroken line of five stones (marks) either vertically, horizontally, or diagonally, wins the game.

In Japan they played with these rules on a 19x19 Go-board since about 700 A.D. when Go was introduced in Japan from China. The game was often called Go-moku but other names are known as well for example Gobang, Morphion. Scientist in Japan are also discussing whether the game named Kakugo mentioned in a writing of the year 100 A.D. is a five-in-a-row game.
The ancient Chinese game of Wutzu is also considered to be a prototype of the Five-In-A-Row games. However the rules are so simple that it is possible that people from different parts of the world may have discovered the game without knowing each other and maybe on other planets of Universe they are also playing the game with the rules 1-2 above.

When the players got stronger they found that playing with the above mentioned rules was in great favour of Black (the beginner of the game). It is also proved that there is a sure win for Black.

In 1899 Japanese players began to play more organized and also changed the name for serious playing from Go-Moku to Renju which means five pearls in a row. However, the game Go-Moku has become even more popular than Renju for the Five-In-A-Row game played in families and in schools.

In 1899 they tried to play with forbidden double-threes for both players to make it more difficult to win. To make a double-three is to make two threes with the same move.

In 1918 it was decided that Black cannot make a 4-3-3 i.e. a four and with the same move a double-three. However making exactly five-in-a-row is never forbidden i.e. 5-3-3 is allowed even if there were suggestions to adopt such a rule especially about 1918.

In the first half of the 20th century one great player was titled Meijin for lifetime (Now the Meijin of Japan is the player who wins the yearly final match including 5 games and with the time limit 5 hours/player and game.) The 1st permanent meijin was Takayama Goraku.The 3rd permanent meijin Takagi Rakazan was also a very good Go-player and his dream was to spread Renju outside Japan. He proposed two new rules.

In 1931 he proposed the change from the Go-board with 19x19 intersections to a Renju -board with only 15x15 intersections. He also proposed double-four to be forbidden for Black. These suggestions were discussed for many years and a split into several organizations using different rules occured. The purpose of all suggestions to changes was of course to reach equal winning chances for both Black and White.

In 1966 all the main organizations joined and created Nihon Renju Sha which is still the Renju Federation of Japan. At that time also some opening rules were made, and the official Renju rules were getting to take shape.

Additional rules of Renju

Rule 3. Black is prohibited from making a double-three, a double-four and an overline. If Black makes one of these patterns either accidentally or by being forced to, he loses the game.

Rule 4. White is not subject to any restrictions and may make double-threes, double-fours, and overlines, an overline having the same winning condition for him as a five.

Rule 5. If neither player has succeeded in making a row of five stones when the board has been played out, the game is called a draw. It is also possible to agree on draw.

Because of Black still has uncompared advantages, there are additional opening rules:

Rule 6. When starting the game, a tentative (temporary) Black, and subsequently a tentative White, are decided between each other.

Rule 7. The tentative Black plays the 1st move on the center intersection.

Rule 8. The tentative White plays the 2nd move direct or indirect at his option. "Direct" means a move made horizontal or vertical to the 1st move and in direct connection with the 1st move. "Indirect" means a move made diagonal to the 1st move and in direct connection with the 1st move.

Rule 9. The tentative Black plays the 3rd move on an empty place within a zone of 5x5 intersection with the same center as the center intersection of the whole board.

Rule 10. Seeing move 3, the tentative White has the right to change sides. If he prefers Black, he changes sides, gives white stones to his opponent, and receives black stones. If, however, he prefers to continue the game with white stones, nothing happens and he simply places the 4th stone wherever he wishes.

Rule 11. White is free to play the 4th move wherever he wants.

Rule 12. Black's Choice. Black has to offer his opponent two possible moves (he deems promising for himself). The two moves must be equal in all respects if you look to the situation in the center of the board. From the two alternatives Black has provided, White tries to evaluate which of the two will be more advantageous to himself and tells Black to make the move he (White) prefers.

Rule 13. There are no restrictions on the sixth and later moves.

With the sophisticated rules of 1-13, the winning conditions are beleived to be equal for both players. These are the official renju rules of the Renju International Federation (RIF), which was founded in 1988 in Stockholm, Sweden.
In "The international rules of renju " , the offical rules of RIF, there are also rules for recording the game, usage of a clock , late arrival, the behaviour of the players, organizing a competition, etc. Rules for time limit and tiebreaking may be different in every single tournament.

By now RIF has nine full members: Japan, Russia, Sweden, Armenia, Azerbaijan, Estonia, France, Latvia and White Russia. The following countries have connection men but are not yet full members: Austria, Bulgaria, Canada, Croatia, Denmark, Finland, Israel, Italy, Moldova, Mongolia, Netherlands, Norway, Poland, Romania, Slovakia, Taiwan, Ukraine, USA, Uzbekistan and Vietnam.

The rules of Pente

Pente was introduced by Gary Gabrel from Stillwater, Oklahoma, USA. At the end of the 1970s it became very popular in the USA, even World Championships were held. Pente is now a registered trademark of Parker Brothers. The main rules are the following:

A. There are two ways to win the game:

1. Win by getting five-(or more)-in-a-row, either horizontally, vertically, or diagonally, with no empty cells between the stones, or

2. Win by capturing five (or more) pairs of your opponents stones.

B. The game begins in the centre of the board and the same rule as d) above is used for the 3rd move.

C. Whenever your opponent has two stones (and only two) which are adjacent, those stones are vulnerable to capture. The pair can be captured by bracketing its two ends with your own stones.

D. A stone may legally be played onto any empty intersection, even if that point has been previously occupied, and even if it forms a pair between two enemy stones. No capture is made by the enemy in this case.

E. Multiple captures are legal.

F. A Pente-board has 19 vertical and 19 horizontal lines like that of a Go-board.

G. White starts the game (which differs from Renju and Go).

The rules of Keryo Pente

Keryo Pente uses the same rules as regular Pente, with the additional rules:

H. 3-in-a-row may also be captured in addition to regular pair captures.

J. In order to win one must get either 5-in-a-row or capture 15 stones.

The rules of Ninuki-Renju

Ninuki-Renju is similar to Pente (except from the opening rule which is probably not used), however Ninuki-Renju introduces some additional rules:

H. The first to form a "perfect 5" or capture five pairs is the winner.

I. Black starts as in Renju . If a five is made and after that White takes a capture and destroys the five there is no win. This is called an "unperfect 5". The destroying of the unperfect five must be made with the move immediately following the five of course.

J. The first player (or sometimes both players) is not allowed to form a double-three, unless it is necessary to do so when destroying an "unperfect 5".

K. An overline (six or more stones in a row) does not win and does not lose.

L. A rare case occurs when a fifth capture gives the opponent a five. This occurs when one stone is captured away from a 6-in-a-row, thus leaving 5. In this case, the game is considered to be a draw game.

The rules of Anti-Renju

This game was introduced by Sergey Zanchenko from Moscow. In this game you can use only the rules 1-2 with the following additional rule:

An open four, i.e. a four which is not stopped by the opponent in either end is forbidden. It means that a three is not so dangerous as usual. The first time you play you will even find it difficult to win!

The rules of Renju with a common center stone

In this game the center stone is black when it is Black's move and white when it is White's move.
Black starts the game in the center of the board.

The rules of Atomic Bomb Renju

Once in a game each player has the right to drop an atomic bomb instead of a usual move. After dropping the bomb this bomb-stone is left on the board, and all other adjacent black and white stones must be taken away. Pente with atomic bomb is also possible to play.

Repensi

This game is a combination of Renju, Pente and Reversi. Instead of capturing two stones these stones are changing colour as in Reversi.

Neutral stone

This is a funny variation of Pente. Each player has two neutral stones in a third colour. Each player has the right to use the neutral stone for a move instead of the ordinary stones for this player. The neutral stone is not possible to capture by neither Black nor White.

Part of this caption is based on the writing of Tommy Maltell, President of Renju Federation posted to rec.games.board and other newsgroups.