Sumo Rules

The rules are based on the official Japanese rules and are based on fair play, and good will. The robot must be active, no cinder blocks allowed. (We have decided to allow sticky wheels, magnets, and vacuum for anyone who wishes to use these to their advantage. You are allowed to put magnets on your robots for improved traction, but the magnets must not touch the surface of the ring.)

The robot must initially fit into a 20 cm x 20 cm square, but can expand beyond this limit after it has been activated. The robot must have a 5 second delay when activated before any motion occurs, to allow the operator time to move away. The robot must not be designed to damage the ring, or the other robots. Battery power only. The robots must be totally autonomous (brains on board) meaning, no remote control or human intervention of any kind, and no tethered, IR, or RF connection to a host computer. The sumo classes are as follows:

Japanese / 3Kg International Class
20cm x 20cm size limit, no height limit.
3.0kg or 105.6 oz (6.6lbs) weight limit.
Will use a 5' ring.

Light Weight / 1 Kg Limited Class
20cm x 20cm size limit, no height limit.
1kg or 35.2 oz (2.2lbs) weight limit.
Will use a 5' ring.

Mini Sumo / 500g Limited Class
10cm x 10cm size limit, no height limit.
500g or 17.6 oz (1.1lbs) weight limit.
Will use a 77cm (30") ring.

Lego Sumo / 1 Kg Limited Class
20cm x 20cm size limit, no height limit.
1 Kg or 35.2 oz (2.2lbs) weight limit.
Will use a 77cm (30") ring.
Parts are limited to any official
or compatable Lego piece, rubber bands,
tape, glue, and cardboard. Requires
that a Lego processor be used.

All you have to do is make sure your robot can push the opponent out of the ring... The official rules as they pertain to judging and officiating can be viewed below.

1. A robot must be in such a size that it can be contained in a box of 200mm(width) x 200mm(depth) x free(height). (Free shape)
2. Robot's Weight must be under 3 kg (Heavyweight class) including all the parts/attachments.
3. Models of robots must be stand-alone.
4. Stand-alone robot must start moving, without operator's manual operation, 5 seconds after the operator pushes the start button when Gyoji announces the start of the match.
5. Any mechanism can be used to control stand-alone robots.
6. Give a Shikona (Name) to your robot.

Specifications of the Ring 
Ring for Robot Sumo 
    Diameter  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 1m54cm 
    Material  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  Hard Rubber 
    Color 
        Inside the ring  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . Black 
        Shikiri line  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . Brown 
        Tawara  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . White 
    Illuminance on the Ring surface  .  .  .  .  Under 1,000 luxes 

Section 1. Definition of the Sumo Match

Article 1. (Definition) The match shall be fought by the two teams (one team consisting of one robot with one or more players, one of which is a leader), according to these Rules for Sumo matches (hereafter called "these Rules"), with each team's robot made by each team (a standalone model) competing to get the effective points (hereafter called Yuhkoh), within the perimeter of the defined Sumo Ring. The judges will decide which team wins.

Section 2. Requirements for Ring Area

Article 2. (Definition of Ring Area) The Ring Area means the Sumo Ring and the space outside the Ring. Anywhere outside this Ring Area is called Outer Area.

Article 3. (Sumo Ring)

1. The Ring shall be in circular shape with its height being 5cm and its diameter 154cm (including the outside of the line that divides the inside of the Ring from its outside). The Ring shall be of 1/16"-thick cold rolled steel.
2. Shikiri lines (where robots stand at the beginning of the match) are the two parallel lines with 20cm distance between the lines, drawn in the center of the Ring. The Shikiri lines are painted in brown, 2cm wide and 20cm long.
3. The Ring shall be marked by a white circular line of 5cm thickness. The Ring is within the outside of this circular line.

Article 4. (Space) There should be the space of more than 100cm wide outside the outer side of the Ring. This space can be of any color except white, and can be of any materials or shape, as long as the basic concept of these rules are observed.

Section 3. Requirements for Robots

Article 5. (Specifications)

1. A robot must be in such a size that it can be put in a box of 20cm wide and 20cm deep. A robot can be of any height. A robot must not be in such a design that its body will be physically separated into pieces when a match starts. The robot with such a design shall lose the match. The design to stretch a robot's body or its parts shall be allowed. Screws or nuts (each within one cubic centimeter) falling off from a robot's body shall not cause the loss of match.
2. The weight of a robot must be under 3000 grams including the attachments and parts
3. For stand-alone robots, any control mechanisms can be employed.
4. Stand-alone models must be so designed that a robot starts operating five seconds after a start switch (or any switch that invokes the operation of a robot) is pressed.
5. Microcomputers in a robot can be of any manufacturers and any memory sizes can be chosen.

Article 6. (Don'ts in manufacturing a robot)

1. Do not disturb your opponent's electronics by putting into a robot's body such devices as a jamming device.
2. Do not use parts that could break or damage the Ring.
3. Do not put into a robot's body devices that can store liquid, powder, or air and throw it to the opponent.
4. Do not use any inflaming devices.
5. Do not use devices that throw things at your opponent.
6. Do not stick a robot down onto the Ring, using sucking devices or glue. (We have decided to allow sticky wheels, magnets, and vacuum for anyone who wishes to use these to their advantage. You are allowed to put magnets on your robots for improved traction, but the magnets must not touch the surface of the ring.)

Section 4. How to Carry Sumo Matches

Article 7. (How to Carry Sumo Matches)

1. One match shall consist of 3 games.
2. The team who received two "Yuhkoh" points first, within the time limit, shall win the match. When the time limit is reached, and one of the teams has received only one Yuhkoh point, the team with one Yuhkoh point shall win.
3. When the match is not won by either team within the time limit, the extended match shall be fought during which the team who receives the first Yuhkoh point shall win. However, the winner/loser of the match may be decided by judges or by means of lots, or there can be a rematch.
4. One Yuhkoh point shall be given to the winner when the judges' decision was called for or lots were employed.

Section 5. Start, Stop, Resume, End a Match

Article 8. (Start) With the chief judge's instructions, the two teams bow in the Outer Ring and go into the Ring Area, place a robot on or behind the Shikiri line or the imaginary extended Shikiri line. (A robot or a part of a robot may not be placed beyond the Shikiri line toward the opponent.). A match starts with the following rules:

1. For stand-alone robots, be ready to press a start switch. Press the switch when the chief judge announces the start of the match. After 5 seconds, the robot starts operating, before which players must clear out of the Ring Area.

Article 9. (Stop, Resume) The match stops and resumes when a judge announces so.

Article 10. (End) The match ends when the chief judge announces so. The two teams bring the robots out of the Ring Area, and bow.

Section 6. Time of Match

Article 11 (Time of Match) One Match will be fought for 3 minutes, starting and ending by the chief judge's announcements. For stand-alone robots, the clock shall start ticking 5 seconds after the start switch is pressed.

Article 12. An extended match shall be for 3 minutes.

Article 13. The following are not included in the time of the Match:

1. The time elapsed after the chief judge announces Yuhkoh and before the match resumes. 30 seconds shall be the standard before the match resumes.
2. The time elapsed after a judge announces to stop the match and before the match resumes.

Section 7. Yuhkoh

Article 14. (Yuhkoh) One Yuhkoh point shall be given when:

1. You have legally forced the body of your opponent's robot to touch the space outside the Ring.
2. A Yuhkoh point is also given in the following cases:
   1. Your opponent's robot has touched the space outside the Ring, on its own reasons.
   2. Either of the above takes place at the same time that the End of the Match is announced.
   3. When a robot has fallen on the Ring or in similar conditions, Yuhkoh will not be counted and the match continues.
   4. When judges' decision is called for to decide the winner, the following points will be taken into considerations:
      1. Technical merits in movement and operation of a robot
      2. Penalty points during the match
      3. Attitude of the players during the match
   5. The match shall be stopped and a rematch shall start when:
      1. Both robots are in clinch and stop movements for 30 seconds, or move in the same orbit for 30 seconds.
      2.  
         1. Both robots move or stop for 30 seconds without touching each other.
         2. If one robot stops it's movement for 30 seconds, he shall be considered not having the will to fight, and the opponent shall receive a Yuhkoh.
         3. Both robots, at the same instance, touch the space outside the Ring.

Section 8. Violations

Article 15. (Violations) If the players perform the deeds as described in Articles 6, 16, and 17, the players shall be declared as violating the rules.

Article 16. The player utters insulting words to the opponent or to the judges or puts voice devices in a robot or writes insulting words on the body of a robot, for the same effect.

Article 17. A player:

1. Enters into the Ring during the match, except when the player does so to bring the robot out of the Ring upon the chief judge's announcement of Yuhkoh or stopping the match. To enter into the Ring means:
   1. A part of the player's body is in the Ring, or
   2. A player puts any mechanical kits into the Ring to support his/her body.
2. Performs the following deeds:
   1. Demand to stop the match without appropriate reasons.
   2. Take more than 30 seconds before resuming the match.
   3. Start operating the robot before the chief judge announces the start of the match (for radio-controlled robots).
   4. Start operating the robot within 5 seconds after the chief judge announces the start of the match (for stand-alone robots).
   5. Do or say that which should disgrace the fairness of the match.

Section 9. Penalties

Article 18. (Penalties) Those who violate the rules with the deeds described in Articles 6 and 16 shall lose the match. The judge shall give two Yuhkoh points to the opponent and order the violator to clear out. The violator is not honored with any rights.

Article 19. Each occasion of the violations described in Article 17 shall be accumulated. Two of these violations shall give one Yuhkoh to the opponent.

Article 20. The violations described in Article 17 shall be accumulated throughout one match.

Section 10. Injuries and Accidents during the Match

Article 21. (Request to stop the Match) A player can request to stop the game when he/she is injured or his/her robot had an accident and the game cannot continue.

Article 22. (Unable to continue the Match) When the game cannot continue due to player's injury or robot's accident, the player who is the cause of such injury or accident loses the match. When it is not clear which team is such a cause, the player who cannot continue the game, or who requests to stop the game, shall be declared as the loser.

Article 23. (Time required to handle injury/accident) Whether the game should continue in case of injury or accident shall be decided by the judges and the Committee members. The decision process shall take no longer than five minutes.

Article 24. (Yuhkoh given to the player who cannot continue) The winner decided based on Article 22 shall gain two Yuhkoh points. The loser who already gained one Yuhkoh point is recorded as such. When the situation under Article 22 takes place during an extended match, the winner shall gain one Yuhkoh point.

Section 11. Declaring Objections

Article 25. (Declaring Objections) No objections shall be declared against the judges' decisions.

Article 26. The lead player can declare objections to the Committee, before the match is over, if there are any doubts in exercising these rules.

Section 12. Requirements for Identifications for Robots

Article 27. (Identifications for Robots) Identifications for robots shall be of red color for the East players, blue for the West. Two seals for identification (2cm in diameter) must be adhered to a body of a robot.

Section 13. Miscellaneous

Article 28. (Flexibility of Rules) As long as the concept and fundamentals of the rules are observed, the rules shall be so flexible that they will be able to encompass the changes in the number of players and of the contents of matches.

Article 29. (Change in Rules) Any changes to or obsolescence of these rules shall be decided by the General Committee Meeting based on the Sumo Match Committee Rules.