Sumo Rules for Central Illinois Robotics Club

Rules for Sumo Competitions

The rules are based on the official Japanese rules and are based on fair play, and good will.

However there are a few minor changes to the Official Japanese rules. There are always people trying to push the edges of the rules or exploit loop-holes in the rules. In order to stop people 'cheating' in this way the rules need to be quite complex, however we don't want to make them so confusing that they can not be followed by everyone. As a result the rules are stated simply and then with a clarification in green where it may be necessary. Most people don't need to read the text in this colour!

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

Official Japanese Rules, English translation, as submitted by Fuji Software Inc.
originally typed by Bill Harrison of Sine Robotics in 1993
Last update September 2005

The sumo classes are:

Heavy Weight (Japanese) / 3Kg Class
20cm x 20cm size limit, no height limit.
3.0kg or 105.6 oz (~6.6lbs) weight limit.
Will use a 152cm (5') ring.

Light Weight / 1 Kg Class
20cm x 20cm size limit, no height limit.
1kg or 35.2 oz (~2.2lbs) weight limit.
Will use a 152cm (5') ring.

Mini Sumo / 500g 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 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 compatible Lego piece, rubber bands,
tape, glue, and cardboard. Requires
that a Lego processor be used.

Rules for Sumo Matches

Section 1. Definition of the Sumo Match

Article 1. (Definition) The match shall be fought by the two robots, according to these Rules for Sumo matches (hereafter called "these Rules" or "the Rules"), with each player or team's robot competing to score points, within the perimeter of the defined Sumo Ring. The judges will decide which robot wins.

Section 2. Requirements for Ring Area

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

Article 3. (Sumo Ring)

The Ring will be circular, either 154cm or 77cm diameter (depending on the class).
The Ring will be have a metal surface.
The surface of the ring will be matt black with a white line around the outside.
The white line will be 5cm wide on the 154cm ring and 2.5cm wide on the 77cm ring.
The Ring will be raised a short distance (2 to 10cm) above the rest of the floor.
The Shikira line is used for the placement of robots. It may or may not be actually marked on the ring, however if it is marked it will be a dark brown.

Article 4. (Space) There should be a space (The Ring Space) of more than 100cm wide outside the outer side of the Ring. This space can be of any colour except white, and can be of any materials or shape, as long as the basic concept of these rules are observed. Once the robots are activated the operators must withdraw to the Outer Area and remain outside the Ring Space until the Judge instructs them to re-enter.

Section 3. Requirements for Robots

Article 5. (Specifications)

A robot must be in such a size that it can be contained in a box of either 20 cm (width) x 20cm (depth) x free (height) or 10cm (width) x 10cm (depth) x free (height) depending on which class it is in. The robot may be any shape.
The Robot's weight may not be more than 3 kg / 1 kg / 500g (depending on class) this includes all parts/attachments and batteries. The Robot must compete with batteries of the same type (size and manufacturer) as it weighs in with (not all batteries of the same size weigh the same). If an operator wants to be able to use more than one type, the robot must weigh in for each and every intended configuration of batteries.
It is advisable (but not compulsory) for you to ensure your robot is slightly underweight or to have some non-vital part that can be removed if at weight in the official scales measure your robot as overweight.The official scales are correct. Even if you have had your robots weight confirmed as within limits by the federal agency of weights and measures, the official scales are all that matters.
Robots must be stand-alone. (No Tethers) This should be obvious as a tether would violate the size restriction.
When the Judge starts the match, the operator pushes the start button. The robot must wait no less than 5 seconds before it starts moving (to give the operators time to step back outside the ring space).
Your Robot should have a name.

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

Do not disturb your opponent's electronics or sensors by putting into a robot's body such devices as an active jamming device. What's the difference between an active jamming and passive jamming? Active means you omit something, passive means you don't. If your opponent uses infra-red light to 'see' your robot. Using an infra-red lamp to blind them is active jamming (and prohibited). Making your robot out of something that permits infra-red light to pass through it (and so appear invisible) is passive jamming (and permitted).
Do not use parts that could break or damage the Ring.
Do not put into a robot's body devices that can store liquid, powder, or air and throw it at the opponent. (Sumo is a non destructive pushing competition).
Do not use any flammable devices.
Do not use devices that throw things at your opponent.
Although the ring is metal, magnets to increase down-force are not permitted. (Magnets may be used elsewhere in the robot, such as within the motors in order to cause it to move, but magnets may not be used to pull the robot down to the ring to increase its down-force.)
Do not stick a robot down onto the Ring, using sucking devices or glue. (We have decided to allow sticky wheels. Vacuum (increasing down-force by creating a partial vacuum under your robot) is not permitted.
Cluster bots (Robots that break into multiple smaller Robots) are not permitted

Section 4. How to Carry Sumo Matches

Article 7. (How to Carry Sumo Matches)

One match shall consist of 2 or 3 rounds (called games in the original rules).
Winning a round will score 1 point.
The team who receives 2 points first shall win the match.
If neither robot has had a clean win within the time limit, once the time limit is reached, the Judge shall declare one of the robots as the winner. The Judge will decide based on which robot was the most active, was the best at hunting it's opponent and was the best at pushing (if the robots meet).
The Judge's decision is final. Always. Even if it's wrong!

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

Article 8. (Start) With the Judge's instructions, the two operators bow in the Outer Ring and go into the Ring Space. For the first round of each match the robots are placed as shown in the diagram in Article 2. One on each side of an imaginary 'Shikira' line dividing the ring in two (the Shikira line may be painted a shade of dark brown). The robots must be placed facing at right angles to each other so that they start heading in almost exactly opposite directions. For subsequent rounds, the robot that won the most recent round, places first somewhere on their side of the Shikira line, the robot that lost places second somewhere on their side of the Skikira line. (This gives the advantage of being able to point directly at their opponent to whomever lost the previous round).
When both robots are placed, the Judge will announce the start of the round. Each operator will press the start button (to start their robots 5 seconds timer) and withdraw outside the Ring Area before the 5 seconds have elapsed.
Article 9. (Pause, Resume) The round stops and resumes when a judge announces so. (Though usually there is no need to pause or resume a round)

Article 10. (End) The round ends when the chief judge announces so. This is either when one Robot has pushed the other out of the Ring or when the time limit is reached. The process is repeated for a second or third match. If any part of the robot touches the Ring Space or Outer Space it is considered to have left the ring. (Thus having pieces drop off your robot is not a good idea). The robot
Once a robot has won two rounds, the Judge shall declare this robot the winner of the match. Each operator brings their robot out of the Ring Area, faces their opponent and bows.

Section 6 Time of Match

Article 11 (Time of Match) Each round will be fought for 1 minute, starting and ending by the chief judge's announcements. The clock shall start 5 seconds after the start switch is pressed.

Article 12. N/A Article numbers are preserved from the original rules, however this section is no longer applicable.

Article 13. N/A Article numbers are preserved from the original rules, however this section do no longer applicable.

Section 7. Scoring of rounds

Article 14. Scoring: One point shall be given when:

Your robot has legally forced the body of your opponent's robot to touch the space outside the Ring.
Your opponent's robot has touched the space outside the Ring, for its own reasons.
Your opponent's robot has stopped moving for 30 seconds (appears to have died).
Time has expired, in which case the Judge will decide a winner based on:

Whichever robot was most active.
Whichever robot appeared to do the best job of searching for it's opponent.
In the case where the robots met and pushed each other, the robot that did the most pushing.
The attitude of the players during the match.

When a robot has fallen on the Ring or in similar conditions, it's opponent is not automatically declared the winner of that round and the round continues.
The round will be stopped and a rematch shall start when:

Both robots are in clinch and stop movements for 30 seconds, or move in the same orbit for 30 seconds.
Both robots stop for 30 seconds without touching each other.
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. If 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:

Enters into the Ring space during the match, except at the beginning to start the robot or at the end upon the Judge's announcement of the end of a round (or a re-start of the round). To enter into the Ring space means:

A part of the player's body is in the Ring, or
A player puts any object (other than the robot in play) into the Ring.

Performs the following deeds:

Demand to stop the match without appropriate reasons.
Take more than 30 seconds before resuming the match.
Permits their robot to starts operating before the 5 seconds have expired after the chief judge announces the start of the match (for autonomous robots).
Does or says anything that interferes with the fairness of the match.

Section 9. Penalties

Article 18. (Penalties) Those who violate the rules with action described in Articles 6 and 16 shall lose the match. The judge shall give two points to the opponent and order the violator to leave. Depending on the nature of the violation the violator may be permitted to compete in subsequent matches.

Article 19. Each occasion of the violations described in Article 17 shall be accumulated. Two of these violations shall give one point to the opponent. (as though the violators robot lost a round).

Article 20. The violations described in Article 17 shall be accumulated throughout one match. Repeated violations across different matches will result in the total disqualification of the competitor.

Section 10. Injuries and Accidents during the Match

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

Article 22. (Unable to continue the Round) 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 round. When it is not clear which team is such a cause, the player who cannot continue the round, or who requests to stop the round, 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. (Point given to the player who cannot continue) The winner decided based on Article 22 shall gain two points (wins the round). The loser who already gained one point is recorded as such.

Section 11. Declaring Objections

Article 25. 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. Robots shall be identified in some way, often by a sticker with the robots name or a unique number or letter issued by the committee at weigh-in. Any such identification must be attached to body of the robot where it is easily visible. i.e. not on the underside or inside of the 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. for example if there are very few robots in a competition, the maximum length of rounds may be increased, or conversely if there are a lot of robots, the maximum length of rounds may be reduced.

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.