Tournament Rules

These rules are base upon those of Fuji Soft ABC, Inc. for the All Japan Robot-Sumo Tournament. While aimed at more local/national tournaments they are intended to be compatible with other national rules. Radio Control has not been included in these rules at this time, however where allowed it should be used in the spirit of the original rules and conform to UK Regulations concerning Radio Controlled Equipment.

Chapter 1 Definition of a match

   Article 1   


A match involves two contestants (one operator per robot can be registered, but may be assisted by their mechanic/team) who start robots that they have made themselves in the Sumo ring ("Dohyo") according to the Game Rules ("Rules"). The contest continues until a ("Yuko") point is scored by one of the contestants. The decision on when a point is scored will be made by the referee.


Chapter 2 Dohyo Specifications

   Article 2   

Definition of the Dohyo interior

The Dohyo interior is defined as the Dohyo area surrounded by and including the border line.

   Article 3   


  • A Dohyo is an MDF or Plywood cylinder with a minimum height of 2.5 cm and a diameter of 77cm (including the border line). The top of the cylinder will be a smooth matt black painted finish.
  • The starting lines ("Sikiri-Sen") are indicated as two brown lines with a width of 1 cm and a length of 10 cm. Each line is located 5 cm from the center of the Dohyo.
  • The border line is indicated as a white circle with a width of 2.5 cm. "On the border" is defined as being within the interior of the Dohyo.
  • During the games, it is up to the referee to decide whether the Dohyo can continue to be used or whether it should be changed when a scratch or tear less than 2.5 cm in length appears on the Dohyo surface.

   Article 4   

Dohyo Exterior

The exterior area of a Dohyo extends at least 50 cm from the border line. The color of the exterior can be any color except white. There are no restrictions on the type of material that can be used or the shape of the exterior as long as they do not violate the spirit of the rules.


Chapter 3 Specifications of the robots

   Article 5   


  • The robot must be able to fit in a box with a width and depth of 10 cm. There are no restrictions on height.
  • Weight (including accessories) must not exceed 500g.
  • There are no restrictions on the type of control method used with self-operated robots.
  • A self-operated robot should be designed to begin action 5 seconds after the contestant presses the robot's start button.
  • There are no restrictions on the brand or memory volume of the microprocessor used for a robot.

   Article 6   

Restrictions on robot design

  • The robot must not include a device that obstructs the opponent's operation, such as a jammer or strobe light.
  • The robot must not include any parts that might damage or deface the Dohyo.
  • The robot must not include a device that blows liquid, powder or gas.
  • The robot must not include a firing device.
  • The robot must not include a throwing device.
  • The robot must not include any part that fixes the robot to the Dohyo surface and prevents it from moving (such as suckers, glue and so on).
  • The robot will not include any device that increases the apparent weight of the robot (such as vacuums, fans, or magnetic systems to push or pull the robot down onto the dohyo surface).


Chapter 4 Game principles

   Article 7   

Game principles

  • A game consists of three matches of three minutes each.
  • The first contestant to win two Yuko points is the winner of the game.
  • The contestant who wins a Yuko point at the end of the game is judged as the winner.
  • When neither contestant receives any Yuko points, the winner is decided by judgment. However, if no obvious superiority exists and a winner can still not be determined, an extra three-minute match can be played.


Chapter 5 Game procedure

   Article 8   

Beginning of the game

  • The contestants enter the Dohyo area, following the chief referee's instructions, to place their robots on or behind their starting lines. The robot cannot outstep the starting line before the match begins.
  • With a autonomous robots, the contestant presses the start button, and exits the Dohyo, on the robot at the referee's signal. The match begins when the robot begins action (after 5 seconds).

   Article 9   

End of the game

The match ends when the referee calls the winner.

   Article 10   

Game canceling and rematches

A match will be canceled or rematched under the following conditions:

  • The robots are locked together in such a way that no more action is possible, or they rotate in circles several times.
  • Both robots touch the exterior of the Dohyo at the same time.
  • Any other conditions under which the referee judges that no winner can be decided.
  • In case of a rematch, maintenance of competing robots are prohibited until a "YUKO" is observed, and the robots must immediately be put back to the location specified in Chapter 8 Article 16.
  • If neither of the competing robots win nor loose even after a rematch, the referee may reposition both robots to a specified location and restart. If even that does not yield a winner, the match may continue at the location decided by the referee, until the time limit is reached.


Chapter 6 Yuko (effective) points

   Article 11   


The following conditions are determined as Yuko points:

  • When a robot ejects its opponent from the Dohyo with a fair action.
  • When the opponent's robot steps out of Dohyo on its own (for any reason).
  • When the opponent's robot is disqualified or has had more than one violation or warning.


Chapter 7 Violations and penalties

   Article 12   


A contestant who takes any of the following actions will receive a warning:

  • The operator or a part of the operator enters the Dohyo before the referee's call ends the match.
  • Preparation for the restart of a match takes more than 30 minutes.
  • The robot begins action (physical expansion or moving) before the referee's start signal.
  • Any other actions that may be deemed unfair.

   Article 13   


Any of the following actions is determined as a violation, and the offender's opponent or both will get a Yuko:

  • A part or parts of the robot that exceed a weight of 5g are separated and dropped from the robot.
  • The robot stops moving on the Dohyo.
  • Both the robots are moving, but don't contact each other.
  • The robot emits smoke.

   Article 14   

Loss by violation

A contestant who takes any of the following actions will lose the game by violation:

  • A contestant does not attend the appointed Dohyo when called at the beginning of the game.
  • A contestant who ruins the game. For example, by intentionally breaking, damaging or defacing the Dohyo.

   Article 15   


A contestant who takes any of the following actions will be disqualified and forced to leave the game. A disqualified person will lose the right to enter the Tournament and to receive a commendation:

  • A contestant's robot does not meet the "Specifications of the robots" stated in Article 5.
  • A contestant makes a robot using a method restricted in Article 6.
  • A contestant displays unsportsmanlike behavior. For example, using violent language or slandering an opponent or a referee.
  • A contestant intentionally injures the opponent.


Chapter 8 Injury and accidents

   Article 16   

Request for suspension

When a contestant is injured or the robot has an accident, and the game can not be continued, a suspension of maximum five minutes can be requested by the contestant.


Chapter 9 Objections

   Article 17   

Objections to the referee

No objections to the judgment of the referee can be raised.

   Article 18   

A contestant who has an objection to the operating Rules must express dissent to the Tournament Committee before the end of the game.


Chapter 10 Specifications of robot markings

   Article 19   

Robot Identification

Some identifying name or number (as registered in the contest) must be easily readable on the robot's body while the robot is in competition.


Chapter 11 Others

   Article 20   

Modifications and abolition of the Rules

Modifications or abolition of the Rules are made by the decision of the Tournament Committees.

Discussion, clarification and proposals in relation to the rules can be put forward in the UK Tournament Rules Forum.


Terms of Use ©, 2005 - 2011. Web Master Contact.