|AN OUTLINE OF RENJU
Renju was previously called Gomoku (Five-in-a-row)
and many of our readers have probably heard
of it by that name. For a long period before
it was given the new name of Renju, people
had played it by very simple and primitive
rules. One of the demerits of this old way
of playing was that no one could make a clear
decision on what to do with a double three.
Some insisted that it be redefined and others
demanded it be prohibited, but everyone was
puzzled anew when he had to use a double
three as a defensive tactic. Again some people
claimed that the one who made it be the loser
while others ruled it a draw or something
Modern Renju is Gomoku with strict and reasonable
rules eliminating all ambiguity. It is a
problem of great importance to detemine whether
you win, lose, or draw when, for instance,
a double three occurs. By means of these
rules, people throughout Japan, and throughout
the world, at last can reany enjoy the game
whether playing with Black or White.
Because of its simple rules, Renju can be
learned easily by anybody who is interested.
Renju boards and stones are obtainable from
Japan, but a pencil and graph paper will
do. In case you would like to study Renju
more deeply, we recommend that you use traditional
One can never know how much fun a game is
without really trying it. Renju is not as
simple as it looks. It is our fear that many
people will regard Renju as nothing but a
childish game before they get to the core
of it. Once you begin to study it, however,
you will never leave it.
RENJU - THE MOST ENJOYABLE GAME
There are a great number of games in the
world. Generally speaking, trivial games
with simple rules do not have any attraction
because it is easy to foresee the result.
A game with complicated rules, on the other
hand, requires too much concentration and
only a limited number of people can enjoy
Renju is different. The rules are very simple
and the game is fascinating and profound.
As you advance, you will be surprised at
its richness in strategies, both offensive
Renju in Japan is a product of accumulated
improvements over a long period of time.
One improvement was to restrict Black's moves
(Black moves first) so as to offset his initial
advantage. Putting restrictions on Black
may seem unfair at first glance, but in reality
it is not. Japanese players are convinced
that this revision has been a great success.
The restrictions on Black are the prohibited
moves which have a somewhat different meaning
from those in Chess or Go. In a game of Renju,
White is always searching for a way to force
Black into a prohibited move while Black
must always be careful not to be forced to
make such a move. Thus, the art of forcing
one's opponent into a prohibition and escaping
from one has made the game extremely interesting.
In fact, the struggle over that critical
point is the very essence of Renju. Because
of it the game has finally gained true appreciation
from serious Japanese players and hopefully
it will find the same appreciation from the
readers of our book.
TERMS AND DEFINITIONS
BROKEN FOUR: A four containing a one-intersection gap
that can become a five in a row in one move.
BROKEN THREE: A three containing a one-intersection gap
that can become a straight four in one move.
DOUBLE FOUR: Two fours, either broken or straight, produced
simultaneously with a single move.
DOUBLE THREE: Two threes, either broken or straight, produced
simultaneously from two two-stone formations
with a single move.
EXTENSION: A move that makes a straight three out of
a straight two or a straight four out ofa
FIVE: Five stones of the same color arranged in
a row, whether diagonally, vertically or
FOUR: Four stones of the same color with one end
stopped or containing a gap along a vertical,
a horizontally, or a diagonal.
FOUR-THREE: A four and a three produced simultaneously
with a single move.
JUMP: A move made at a one-intersection interval
from a straight two (two stones in a row,
unstopped) or from a straight three, usually
stopped at one end.
OVERLINE: Six or more stones of the same color in a
diagonal, vertical, or horizontal row.
PROHIBITION: A move which, if made by Black, causes him
to lose (for example a double/triple three,
a double/triple four, and an overline). Also
'a prohibited move'. Such moves are indicated
in diagrams by X and Y.
STRAIGHT FOUR: Four stones of the same color in a row (diagonally,
vertically or horizontally) with both ends
open. A straight four ensures a win.
THREE: Three stones of the same color in a row
or contaiming a one-intersection gap along
a vertical, a horizontal, or a diagonal that
can become a straight four on the next move.
VCF: A win that results from making fours one
after another. in this book, 'series of fours',
'series of continuous fours', 'series of
consecutive fours', 'continuous fours' or
'consecutive fours' all mean VCF.
VCT: A win that results from making threats (that
is, making a three which threatens to become
a straight four, or making a four which threatens
to become a five) one after another. In this
book, 'series of threats', 'series of continuous
threats', 'series of consecutive threats',
'continuous threats' or 'consecutive threats'
all mean VCT.
DAN: A ranking given to strong players. Begins
at shodan or 1-dan and continues up to 9-dan,
the highest ranking. In Renju the same ranking
system applies to both professionals and
amateurs. See KYU.
FUKUMI: A move which threatens to win by making consecutive
GOTE: A move which loses the inlthtive; the opposite
of SENTE. Also used for Black at the beginning
of the game.
JOSEKI: An established pattem of good play in the
KYU: A ranking given to weaker players. Unlike
the dan rankings, the smller the kyu, the
higher the rank; consequently, a player is
promoted from 1-kyu to 1-dan. Though impossible
to determine, perhaps a raw beginner starts
at about 15-kyu. See DAN.
MEIJIN: A title given to a player who has established
himself as the strongest player in the world.
MISE: A move which threatens to make a four-three.
SENTE: A move which keeps the initiative by forcing
the opponent to answer. For example, 'Black
has sente' means it is Black's move. The
opposite of GOTE. Also used for White at
the beginning of the game.
YOBI: An offensive move, but one which does not
carry a direct threat.
THE RULES OF RENJU
Now that you might have become interested
in Renju, what are the rules? There are five,
and since you probably already have a vague
idea of them, there is not really so much
you will have to learn that is entirely new.
Rule 1: Play alternates between Black, called Sente, and White, called Gote, on the intersections of a board with flfteen
vertical and fifteen horizontal lines. Black
plays flrst and must place his flrst move
on the Center intersection.
Rule 2: The first Player to get an unbroken line
of five stones,
whether vertically, horizontally, or diagonally,
wins the game.
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
Rule 4: White is not subject to any restrictions
and may make double threes, double fours,
and overlines, an overline having the same
value 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 caned a draw.
Of the five rules the rule governing prohibited
moves is the only one that may cause the
reader difficulty, therefore, in the following
pages he should be careful to grasp what
exactly makes a prohibited move, especially
in the case of double threes since some formations
may appear to be double threes but actually
At the kyu level, a Renju match usually consists
of two games, each player taking the black
stones once. The main reason for this is
that it is difficult for a player holding
White to win until he
becomes six or seven kyu because he has not
yet become skillful enough to exploit Black's
prohibited moves. By the time that he has
become shodan, however, he can usually play
Black and White with
equal ability. Incidentally, being able to
win with White is a fair indication that
a player has reached about 6-kyu.
PROHIBITIONS - WHY FOR BLACK ONLY?
In Renju the first player always takes Black
and the second player White, and so when
"Black", it means the first player
and when we say "White", it means
the second player.
Should the two phyers try to get five according
to the "perfectly free" rules -
that is, with no restrictions for either
side - Black can a every game very easily.
In order to adjust this imbalance, which
is caused by Black moving first, some conditions
been imposed on Black. In other words the
rules have been made unfair to make the game
As the study of the game advanced, our predecessors
prohibited Black's double three, but they
soon found that this was still insufficient.
Therefore, Black's double four and overline
(more than five in a row) were also prohibited.
At the same time the Renju board was diminished
to 15x15 lines when it was discovered that
a board bigger than 15x15 helped Black win
with ease. A smaller board, by the way, would
make the game drawn more often and therefore
less interesting. The size of the present
board seems perfect.
Remember again that White has no prohibitions
at all imposed on him and that an overline
as a five will win the game for him.
All revisions in the rules such as prohibited
moves for Black and the smaller 15x15 board
as well as the special playing rules, are
regarded by all Renju players as epoch-making
progress in the history of Renju.
We owe much to the great men of the past
who made these rules.
From FIVE-IN-A-ROW by Goro Sakata & Wataru