World Othello Championship Official Rules


1. Contestants: The World Othello Championship shall be held annually
to determine the World Othello Champion and the World Othello Team
Every nation may present up to three contestants, with the exception
of the hosting country (see II.2). Before the tournament, the
tournament organisers may, in case of serious doubt, request a player
to present his credentials as a representative of his country.

2. The Officials: The host country shall arrange for the services of
a chief referee and other tournament officials. There shall be
sufficient officials to provide a scorer for each tournament game.
The chief referee shall be responsible for the running of the
tournament, including the pairings process and adherence of players
and spectators to the rules described herein, and shall be the arbiter
of any disputes arising during the tournament. A decision of the
chief referee may, in exceptional circumstances, be appealed to the
Council of Federations: see V.

The chief referee shall appoint table officials (see IV.2), who will
transcribe the games. If possible, the tournament officials should
arrange for the four semi-finalists to receive transcripts of their
prospective opponents' games in time to prepare for the third day of

3. Playing Conditions

3.1 The Tournament Room: The host country shall endeavour to provide
the contestants with good playing conditions. The tournament room
shall be quiet and well lit. (Indirect lighting is preferred because
direct light reflects off the shiny surfaces of the playing discs,
making it difficult to distinguish their colour).

3.2 Consultation: During the course of the game, a player may not
consult any notes or exchange information of any kind with another
person, with the exception of a tournament official.

3.3 Smoking: It is strictly forbidden to smoke in the tournament room.

3.4 Mobile phones: Mobile phones brought into the tournament room must
be switched off.  If someone forgets to do so and their phone happens
to ring in the tournament room, they must not answer the call but must
immediately switch the phone off.

4. Spectators: Spectators are permitted in the tournament room at the
discretion of the chief referee. Spectators and other contestants are
permitted to observe a game in progress, but must not interfere in
any way with conduct of the game. In particular, observers must
refrain from making any comments on the game, or in any way
distracting the players or the table referee. However, if another
player detects any irregularities in the game, he may mention them to
the chief referee or one of his assistants.


1. Overview: There will be three days of tournament play. The aims of
the first two days of competition are:

a) To select four players who will compete on the third day for the
individual title.

b) To decide the World Othello Team Championship.

The third day of competition will be organised as follows:

a) There will be two semi-finals, one played between the first and
fourth-ranked players from the first two days of competition, and the
other between the second and third-ranked. These are to be the best
of three-games matches
b) There will be a final, organised as a best of three-game match
between the winners of the two semi-finals, and a one game play-off
for third place between the two losing semi-finalists.

2. Playing System: During the first two days of the tournament, the
system used will depend upon the number of contestants in the
tournament as set out below:

a) Up to 8 players: A double Round Robin.
b) 9-14 players: A single Round Robin.
c) 15-24 players: A modified Swiss system.
d) More than 24 players: An unmodified Swiss system.

See II.5 for further details. If a Swiss system is to be used, seven
rounds will be played on the first day and six on the second.

If there would otherwise be an odd number of players, the host
country may enter an additional player in the tournament to prevent
the introduction of a bye. This player shall be designated as the
country's fourth player before the beginning of the tournament.

If the host country has already entered three players, the points
gained by the designated fourth player shall not count for the team

However, the fourth player shall have the same status as the other
players as regards the individual championship, and, in particular,
shall have a full right of access to the semi-finals and final.

3. Individual Final Ranking List (IFRL): At the end of the first two
days of competition, the officials will draft the Individual Final
List Ranking (IFLR) following the procedure set out below:

3.1 Provisional List: A provisional list is first drawn up, players
being arranged in order of number of points scored in the tournament -
 one point will be awarded for each win and half a point for each
draw; in case of ties, the Mixed Brightwell System (MBS) will be used
to separate the contestants (see appendix A).

If the fourth and fifth-ranked players in the provisional list have
the same number of points, they will play a play-off game. In this
game, the fourth-ranked player shall have the choice of colour and
shall be declared the winner if the game is drawn.

3.2 Final List: The IFRL is the same as the provisional list with two

a) If a play-off game was necessary as in II.3.1, the winner of that
game is placed fourth in the IFRL and the loser fifth.

b) Any players not ranked among the top four and having the same
number of
points are declared equal.

4.Team Final Ranking List (TFRL) The final ranking list used to
determine the World Othello Team Champion will be drafted as follows:
The officials will calculate for each team the sum of the points
scored by its members, and the ranking list will be drawn up
according to this sum. (If the host country has provided four
players, the points scored by the designated fourth player will not
be taken into account.) In case of a tie for first place, the country
with the greatest number of games between members of its team shall
be declared the champion. If two or more teams are still tied for
first place, the team having the top player in the IFRL will take
preference. In case of a further tie, the team whose second-ranked
player is higher in the IFRL will take preference. In case of a
further tie, the tied teams will be declared equal.

5. Pairings when a Swiss system is used

5.1. First round

The pairings for the first round shall be determined as follows:

- The players are divided into Group A, those who have played in at
  least one semifinal of the previous ten World Othello Championships,
  and Group B, all other players.

- Two players are chosen at random, one from Group A and the other from
  Group B.  They are paired against each other, with the player from
  Group A assigned black.

- This is repeated, with the player from Group A assigned alternately
  black and white, until one of the two groups is empty.

- The remaining players are paired by random draw.

5.2. Second and subsequent rounds

In determining the pairings for the second and subsequent rounds in a
Swiss system, the following rules should be followed, in decreasing
order of priority:

i) Two players from the same team cannot play against each other in
the last two rounds.

ii) If an unmodified Swiss system is used, two players who have
already played against each other cannot be paired together again. If
a modified Swiss system is used, two players who have played against
each other twice cannot be paired together.

iii) The two players paired together should have the same number of
points. If this is not possible, the difference should be minimal.

iv) In a modified Swiss system, if possible, players who have already
played against each other should not be paired together again.

v) Players should tend to play black and white the same number of
times during the tournament. If this is not possible, the difference
should be minimal.

vi) A player who has already "floated up" should "float down", and a
player who has already "floated down" should "float up".

vii) Players should alternate colours from round to round.

6. Withdrawals: If a player withdraws from the tournament, he may not
In particular, he may not qualify for the semi-finals or final.
However, his score at the time of his withdrawal will be entered in
the IFRL and be taken into account in the TFRL. A player who has
withdrawn will not be considered for the purposes of pairing rounds
after his withdrawal, and instead a dummy player called "BYE" will be
introduced into the pairing process. See also Appendix A for the
effect of a withdrawn player on the calculation of the MBS.


1. Best of Three-Game Matches: The higher-ranked player in the IFRL
shall have choice of colour for the first game of the match.

Each player shall be awarded one point for each win and a half point
for each draw in the match.

Colours shall be reversed for the second game. If a player wins both
the first and second game of a match, then that player shall be
declared the winner and a third game shall not be played.

Choice of colour for the third game, if necessary, shall be awarded
to the player having the greater number of discs in the first two
games. In the case of a tie, the higher ranked player shall have
choice of colour.

At the end of three games the player having more points in the match
shall be declared the winner. If after three games the two players
have the same number of points, the total number of discs in the
three games shall be used to determine the winner. In case of a
further tie the higher ranked player in the IFRL shall be declared
the winner.

2. Semi-Finals: At the beginning of the third day of competition, the
four top players in the IFRL will compete in the semi-finals. Each
semi-final match will be a best of three-games match.

The two winners of the semi-finals will advance to the final.

The top-ranked player in the IFRL will play against the fourth-ranked
player, and the second-ranked player will play against the third-
ranked player.

3. Play-Off For Third Place: The two losers in the semi-final will
play a single play-off game for third place. The higher ranked player
in the IRFL will have the choice of colour and will be awarded third
place if he wins or if the game is a draw. The two winners of the
semi-finals will advance to the final.

4. Final: The final will be a best of three-games match. The winner
will be awarded the title of World Othello Champion.


1. Time Limits: Clocks will be used to time all tournament games.
During the first two days each player shall have 30 minutes to
complete all his moves in each game. During the semi-finals, each
player shall have 35 minutes per game. In the final, each player
shall have 40 minutes per game. In the play-off for third place, each
player shall have 35 minutes. If for any reason these time limits
cannot be applied, games should never be played with less than 25
minutes for each player per game.

2. The Table Official: For each tournament game, the chief referee
shall assign one of the tournament officials to be the table
official, who shall be responsible for making a transcript of the
game, observing the rules of Othello and ensuring the smooth running
of a game.

Before the beginning of the game, the table official shall make sure
that both players have enough discs to complete the game. It is the
official's duty to regulate the clock and place it on the right of
the player with the black discs (unless both players agree to do

During the game, the table official should attempt to make a
transcript of the game without requiring the contestants to announce
their moves. The record keeping process must never be allowed to
interfere with the player's concentration.

If, during the game, a player is left without discs, the table
official shall arrange for a sufficient number of discs to be
transferred from the player's opponent. To do that he is allowed to
stop the clocks for the time required.

3. Objects on the Board: No objects of any kind may be placed on the
board with the exception of those Othello discs forming the position
and the one Othello disc used by the player to carry out his move.

4. The Move: A player commits himself to a move if he touches the
board with his hand or with a disc, with the apparent intention of
moving to a given square. In this case, provided the player has a
legal move to that square, he must move to the first square he
touches, and may not change his mind and move instead to a different
square, even if his opponent authorises him to take back his move.
The purpose of this rule is to prevent an indecisive player from
distracting his opponent or obstructing his opponent's view of the
board. A player shall not be bound by this rule, if in the opinion of
the table official, he touched the
given square unintentionally.

Once a player has committed himself to a move, he is bound to turn
over all of the captured discs. He must do this using one hand only,
and then use the same hand to press his clock. If, having played a
move, a player forgets to press his clock, the table official should
tell him to do so.

5. Illegal Moves:

5.1 Procedure: The scorer is present to enforce the Rules of Othello.
An error in the play of a move which has just been played but not yet
answered may be brought to the attention of the table official by
either player, by the chief referee or by one of his assistants. Once
the table official notices, or is informed of such an error, he shall
adopt the following procedure:

a) Restart the clock of the player who committed the error.
b) Correct the error himself, and
c) Restart the clock of the player whose turn it is to move.

5.2 Accepting the Position: Only the most recent move is subject to
When a player commits himself to a new move, he tacitly accepts the
board position as it is, and neither he nor the official can later
seek to correct a previous error.

5.3 Unreadable Position: The players must play their moves and centre
the discs so that the position is clearly readable.

If, in the opinion of the table official, the position becomes
unreadable, he should take any action to correct it (including
stopping the clocks and playing through the transcript). He may also
invite the chief referee to impose some penalty on the offending

6. Time Defaults: A player forfeits the game unless he can make his
final move, flip all the appropriate discs, and stop his clock before
the flag on his clock falls. If a player's flag falls, he loses the
game and his opponent is awarded a win regardless of the position of
the board.

The defaulting player is given two extra minutes. The game is then
continued with the true final score standing, save that the non-
defaulting player is guaranteed at least a 33-31 win. If the
defaulting player's flag falls a second time, the game is scored 64-
0. If the flag of the non-defaulting player falls, he too is given an
extra two minutes, and the true score stands, unless his flag falls a
second time. In this last case, the game is scored as a 33-31 win for
the non-defaulting player.

7. Defective Clock: If, in the course of the game, the clock in use
is found to be defective, the table official shall summon the chief
referee, who will take whatever action he deems appropriate.

8. Scoring: At the end of the game, if both players have completed
their moves in the alloted time, the winner is the player with the
greater number of discs of his colour on the board at the end. The
official score of the game will be determined by counting up the
discs of each colour on the board, counting empty squares for the

In the event of a draw, the score will always be 32-32. If one player
defaults, the scoring is carried out as in IV.6 above.

A player should not resign a game before it is finished, if he does,
the official score shall be 64-0 in favour of his opponent.


1. Composition: Each National Othello Federation (or National
Association of Othello Players) may mandate one person to represent
it in the Council of Federations.

2. Meeting: The Council of Federations may be called at any time
(including in the course of the World Othello Championship) at the
request of one third of its members, or during the World
Championships, at the request of the chief referee.

3. Quorum: The quorum for the Council of Federations shall be six.
The Council may not legislate if fewer than six members are present.

4. Postal Votes: The Council may take by mail any decision it has the
power to make in the course of a meeting.

5. Powers of the Council:

5.1 Overview: The Council may legislate on any subject of its choice
pertaining to the game of Othello. On any matters except those
covered by 5.2 and 5.3 below, normal voting procedures apply and a
motion is carried if it has the support of more than half of the
members present.

5.2 Removal of the Referee: The Council has the power, in extreme
circumstances, to remove the chief referee at the World Championships
and replace him with another person. To secure the removal of the
referee requires the support of two-thirds of the members present.

5.3 Modification of Rules: The Council has the power to modify the
present Rules for the World Othello Championship. To secure such a
modification requires the support of two-thirds of the members

5.4 Others Powers: The Council has the power to overturn a decision
of the chief referee, it may mandate a person to speak in the name of
the Council. It may also appoint committees and transfer to them part
of its powers.


1. Overview: In order to enforce both the rules of Othello and the
World Championship Rules, the chief referee (and only he) may impose
penalties on a player or on a spectator.

In imposing penalties, the chief referee should adjust the severity
of the penalty to the severity of the offence and never penalize a
non-offending player.

2. Penalties: The chief referee may impose the following penalties on
a player or on a spectator:

a) Removing time from an offending player's clock and/or giving
additional time to his opponent's clock.

b) Changing the final score of a game to the benefit of the offending
player's opponent.

c) Declaring the game to be a draw or awarding the game to the
offending player's opponent.

d) Expelling temporarily or definitively from the tournament room a
player or a spectator.

e) Expelling a player from the tournament.


The Mixed Brightwell System (MBS)

1. Overview: The Mixed Brightwell System (MBS) is a method of
breaking ties in Othello tournaments run with the Swiss system. It is
also applicable to Round Robin tournaments, where it is equivalent to
disc-count. Essentially this system is a combination of Strength-of-
Opposition and disc-count.

2. The Constant C: MBS depends on a constant C, which is a weighting
for the relative importance of Strength-of-Opposition and disc-count.
For the World Championships, assuming that they are run either as a
Round Robin or as a 13 rounds Swiss system, C will be set equal to 6.

3. The Brightwell Quotient (BQ): After the end of the tournament, the
tournament officials will evaluate, for each player involved in a
tie, the BQ. This is calculated as follows:

a) If any of the player's opponents have withdrawn in the course of
the tournament, ignore any such games for the moment. Also, if a
player has been paired against "Bye", leave out such a game.

b) Calculate the total number of discs scored by the player in all
games not covered by a) and add C times the sum of points scored in
the tournament by all of the players opponents, except those who have

c) For each game against an opponent who has withdrawn, and each bye
received, add 32 plus (C times the player's own tournament score) to
the result calculated in b). The number resulting is the player's BQ.

4. Resolving Ties: If two players have the same number of points in
the tournament, the tie shall be resolved in favour of the player
with the higher BQ.
If two players have the same number of points and the same BQ, the
tie shall be resolved favour of the player with the better disc
count. In case of further tie, it shall be resolved by the flip of an
Othello disc.