RoboCupJunior Soccer Rules 2020
Soccer Technical Committee 2019
Tairo Namura (Japan)
James Riley (Australia)
Mikail S. Arani (Canada)
Javier E. Delgado Moreno (Mexico)
Felipe Nascimento Martins (Netherlands)
Marek Šuppa (Slovakia, CHAIR)
Soccer Technical Committee 2018
Sarit Salzman (Israel)
James Riley (Australia)
Michael Sloan Warren (USA)Javier E. Delgado Moreno (Mexico)

Felipe Nascimento Martins (Netherlands)
Marek Šuppa (Slovakia, CHAIR)
RoboCupJunior General Chairs
Nerea de la Riva Iriepa (Sweden, CHAIR)
Julia Maurer (USA)
Shoko Niwa (Japan)
Trustees representing RoboCupJunior
Amy Eguchi (USA)Gerard Elias (Australia)
Fernando Ribeiro (Portugal)
Gerald Steinbauer (Austria)

These are the official Soccer rules for RoboCupJunior 2020. They are released by the RoboCupJunior
Soccer Technical Committee. The English version of these rules has priority over any translations.
Teams are advised to check the RoboCupJunior Soccer site https://junior.forum.robocup.org/ for OC(Organizational Committee) procedures and requirements for the international competition. Eachteam is responsible for verifying the latest version of the rules prior to competition.

Preface
In the RoboCupJunior soccer challenge, teams of young engineers design, build, and program two fullyautonomous mobile robots to compete against another team in matches. The robots must detect aball and score into a color-coded goal on a special field that resembles a human soccer field.
To be successful, participants must demonstrate skills in programming, robotics, electronics andmechatronics. Teams are also expected to contribute to the advancement of the community as awhole by sharing their discoveries with other participants and by engaging in good sportsmanship,
regardless of culture, age or result in the competition. All are expected to compete, learn, have fun,and grow.
RoboCupJunior Soccer consists of two sub-leagues: Soccer Open and Soccer Lightweight. These rules
apply for both sub-leagues. There are two main differences between the two leagues.
●●

Soccer Lightweight is played using a special ball that emits an IR signal ball. Robots may weigh
up to 1.1 kg, have a ball-capturing zone of up to 3.0 cm, and use batteries up to 12.0 nominal
voltage.
Soccer Open is played using a passive, brightly colored orange ball. Robots may weigh up to

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voltage.
Please see Section 6 for balls specifications and Section 9 for more details for
specifications/regulations.

Figure 1 Two teams of two robots with an orange ball on a RoboCupJunior Soccer field.

1 Changes from 2019 RoboCupJunior Soccer Rules
The changes determined by the Technical Committee for this year’s rules aim to reduce the amountof ”sumo-like” gameplay while making it more interesting by introducing new challenges and standard
situations.
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Deleted “If the attacker and the goalie touch each other and at least one of them has physicalFinal Rules as of December 19, 201936

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contact with the ball, the ball will be moved to the nearest unoccupied neutral spot
immediately.”
Deleted “If all robots have moved out of bounds, the penalties are discarded and the match
resumes with a neutral kickoff.”
Deleted “It is recommended that the field be positioned 70 to 90 cm off the ground.”Deleted “A robot is considered inside the penalty area when it is completely inside.”
Added “No robots are supposed to be fully inside the penalty area. As the penalty areas aremarked with a white line, the ‘out-of-bounds’ applies to this line as well.”
Added “If an attacking and defending robot touch each other while at least one of them ispartially inside the penalty area, and has physical contact with the ball, this is called ‘pushing’
and the ball will be moved to the furthest unoccupied neutral spot immediately.”
Added “If two robots from the same team are at least partially in the penalty area, one ofthese robots will be moved to the furthest unoccupied neutral spot immediately. If thishappens repeatedly, a robot may be deemed damaged (‘damaged-robots’) at the referee's
discretion.”
Added “If a robot does not touch the ball that is placed no further than 20 cm from it within
10 seconds, it is deemed to be damaged (see Damaged Robots)”
Added “It is recommended that the blue be a bright shade so that it is different from the black
exterior.”
Added “The Technical Committee intends for the diameter/height of robots in the Open subleague to be 20 cm for the 2021 season, with further decrease to 18cm from the 2022 season
onwards. Similarly, the weight of 2300 g is intended to be used in the 2021 season, withfurther decrease to 2200g in 2022.”
Added “A penalty kick takes place after a grave offense happens.”
Added “The kicking procedure consists of the following steps:”
Added “All robots as well as the ball are removed from the field.”
Added “The offending (”kicking”) team places a robot inside its own penalty area, rotatedtowards its own goal. A ball is placed at the central neutral spot.”
Added ”The offending (”kicking”) team turns their robot on. The robot needs to stay still forthe next 5 seconds.”
Added ”During these 5 seconds the defending team places a robot which is turned off inside
its own penalty area.”
Added ”In order to score a goal, the offending team’s robot needs to move the ball inside theopponents goal. It needs to do so in at most 15 seconds while staying within the center circle
once it touches the ball.”
Added “If the offending team’s robot moves before the 5 seconds passes, the result is
automatically no goal. Once the penalty kick finishes, the game continues with a “kick-off”
with the defending team kicking-off.”
Added “In order to help newcomers experience the RoboCupJunior Soccer competition, theTC would like to encourage local and/or regional competitions to introduce and offer a socalled “Intro League.” Although such a league will not be part of the international competition,
the TC believes that it is worthwhile to make it part of regional and super-regional
competitions. Each regional and super-regional competition could have its specific rules but
the TC would like to suggest they contain the following:”
Added “The Intro League should be based on the RoboCupJunior Soccer rules”

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Added “Only competitors that did not previously participate in an international (that is not a
regional or super-regional) competition are allowed to take part.”
Added “It may be worth creating two sub-leagues: a 2v2 sub-league where two robots from
one team play against two robots from the other, and a 1v1 sub-league where both teams
play with just one robot.”
Added “The Intro League should ignore the ‘Out of Bounds’ rule. When robots go out ofbounds, the referee should put them back in.”
Added “The robots should be created from a commercial robot kit(s) widely available in a
specific region, except for sensors necessary for robots to be able to find the ball (i.e. balldetector) and the orientation of the field (i.e. compass). ”
Added ”The robots should be limited in size to 22.4 cm by 22.4 cm by 22.4 cm (allmeasurements +/- 1cm ). There shall be no weight limit.”
Changed ”When the goal difference reaches 10, the game finishes regardless of the state of
the game clock” to ”The final game score will be adjusted so that there is at most a 10 goaldifferential between the losing and the winning team.”
Changed ”any other” to ”an opposing”
Changed ”22 +/- 2 cm of height” to ”at least 5 cm above the highest structure of the robot”
Changed ”30 cm” to ”25 cm”
Changed ”30 cm” to ”25 cm”
Changed ”90 cm” to ”70 cm”
Changed ”black” to ”white”
Changed ”The fields should be placed in a way that the influence by external infrared light is
as low as possible and that the magnetic field of the earth is disturbed as little as possible.
Perfect conditions cannot be guaranteed, however. Teams must come to tournaments
prepared to calibrate their robots based on the lighting and magnetic conditions at the venue”
to ”The organizers will do their best to limit the amount of external lightning and magnetic
interference. However, the robots need to be constructed in a way which allows them to workin conditions that are not perfect (i.e. by not relying on compass sensors or specific lightning
conditions).”

Construction and Programming have to be performed exclusively by the students
Robots must be constructed and programmed exclusively by student members of the team. Mentors,
teachers, parents, or companies should not be involved in the design, construction, assembly,
programming, or debugging of robots. To avoid embarrassment and possible disqualification, it isextremely important that teams abide by league regulations, especially construction andprogramming.
If in doubt, please consult with your Regional Representative before registering your team.

2 GAMEPLAY
2.1 Game procedure and length of a game
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autonomous robots. The game will consist of two halves. The duration of each half is 10-minutes.
There will be a 5-minute break in between the halves.
The game clock will run for the duration of the halves without stopping (except if or when a referee
wants to consult another official). The game clock will be run by a referee or a referee assistant (seeSection 8.1 for more information on their roles).
Teams are expected to be on the field 5 minutes before their game starts. Being at the inspection table
does not count in favor of this time limit. Teams that are late for the start of the game can be penalized
one goal per 30 seconds at the referee’s discretion.
The final game score will be adjusted so that there is at most 10 goal difference between the losing
and the winning team. 1

2.2 Pre-match meeting
At the start of the first half of the game, a referee will toss a coin. The team mentioned first in thedraw shall call the coin. The winner of the toss can choose either which end to kick towards, or to kickoff first. The loser of the toss chooses the other option. After the first half, the teams switch sides. The
team not kicking-off in the first half of the game will kick-off to begin the second half of the game.
During the pre-match meeting the referee or their assistant may check whether the robots are capableof playing (i.e., whether they are at least able to follow and react to the ball). If none of the robots arecapable of playing, the game will not be played and zero goals will be awarded to both teams.

2.3 Kickoff
Each half of the game begins with a kick-off. All robots must be located on their own side of the field.
All robots must be halted. The ball is positioned by a referee in the center of the field.
The team kicking-off places their robots on the field first. Robots cannot be placed nor remain behind
the goal line or in the outer area. Robots cannot be repositioned once they have been placed.
The team not kicking-off places their robots on the defensive end of the field after the team kickingoff places their robots on the field. All robots on the team not kicking-off must be at least 30 cm awayfrom the ball (outside of the center circle).
Robots cannot be placed behind the goal line or out of bounds. Robots cannot be repositioned once
they have been placed, except if the referee requests to adjust their placement to make sure that the
robots are placed properly within the field positions.

1

In previous version this said ”When the goal difference reaches 10 the game finishes regardless of the state of the game clock.”

Final Rules as of December 19, 201936

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Any robots that are started early will be removed by the referee from the field and deemed damaged.
Before a kick-off, all damaged or out-of-bounds robots are allowed to return to the playing field
immediately if they are ready and fully functional.
If no robots are present at a kick-off because they have moved out-of-bounds (Section 2.9) or aredamaged (Section 2.10), the penalties are discarded and the match resumes with a neutral kick-off(Section 2.3.A).

2.3. A Neutral kick-off
A neutral kick-off is the same as the one described in Section 2.3 with a small change: all robots needmust be at least 30 cm away from the ball (outside of the center circle).

2.4 Human interference
Except for the kick-off, human interference from the teams (e.g. touching the robots) during the gameis not allowed unless explicitly permitted by a referee. Violating team/team member(s) can bedisqualified from the game.
The referee or a referee assistant can help robots get unstuck if the ball is not being disputed nearthem and if the situation was created from normal interaction between robots (i.e. it was not a designor programming flaw of the robot alone). The referee or a referee assistant will pull back the robots
just enough for them to be able to move freely again.

2.5 Ball movement
A robot cannot hold a ball. Holding a ball is defined as taking full control of the ball by removing all ofdegrees of freedom. Examples for ball holding include fixing a ball to the robot’s body, surrounding aball using the robot’s body to prevent access by others, encircling the ball, or somehow trapping theball with any part of the robot’s body. If a ball does not roll while a robot is moving, it is a good
indication that the ball is trapped.
The only exception to holding is the use of a rotating drum (a ”dribbler”) that imparts dynamic backspin on the ball to keep the ball on its surface.
Other players must be able to access the ball.

2.6 Scoring
A goal is scored when the ball strikes or touches the back wall of the goal. Goals scored either by anattacking or defending robot have the same end result: they give one goal to the team on the opposite
side. After a goal, the game will be restarted with a kick-off from the team who was scored against.
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No robots are supposed to be fully inside the penalty area. As the penalty areas are marked with awhite line, the Section 2.9 applies to this line as well.
If an attacking and defending robot touch each other while at least one of them is at least partiallyinside the penalty area, and at least one of them has physical contact with the ball, this iscalled ”pushing” and the ball will be moved to the furthest unoccupied neutral spot immediately.
If two robots from the same team are at least partially in the penalty area, one of these robots will
be moved to the furthest unoccupied neutral spot immediately. If this happens repeatedly, a robot
may be deemed damaged (Section 2.10) at referee’s discretion.
If a goal is scored as a result of this pushed-situation it will not be granted. 2

2.8 Lack of progress
Lack of progress occurs if there is no progress in the gameplay for a reasonable period of time and thesituation is not likely to change. Typical lack of progress situations are when the ball is stuck between
robots, when there is no change in ball and robot’s positions, or when the ball is beyond detection orreach capability of all robots on the field.
After a visible and loud count, the referee will call ”lack of progress” and will move the ball to thenearest unoccupied neutral spot. If this does not solve the lack of progress, the referee can move theball to a different neutral spot. 3

2.9 Out of bounds
If a robot’s entire body moves beyond the white line of the field, it will be called for being out ofbounds. When this situation arises, the robot is given a one-minute penalty, and the team is asked toremove the robot from the field. There is no time stoppage for the game itself. The robot is allowed
to return if a kick-off occurs before the penalty has elapsed.
The one-minute penalty starts when the robot is removed from play. Furthermore, any goal scored by
the penalized team while the penalized robot is on the field will not be granted. Out-of-bounds robots
can be fixed if the team needs to do so, as described in Section 2.10.
After the penalty time has passed, the robot will be placed on the unoccupied neutral spot furthestfrom the ball, facing its own goal.

2

In previous version this said ”If the attacker and the goalie touch each other and at least one of them has physical contact with the ball,the ball will be moved to the nearest unoccupied neutral spot immediately.”3

usually a count of three, the length of the count could be decided by the OC before a competition as long as it’s the same length within a
sub-league

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Page 7 ofA referee can waive the penalty if the robot was accidentally pushed out of bounds by an opposing4
robot. In such a case, the referee may have to slightly push the robot back onto the field.
The ball can leave and bounce back into the playing field. The referee calls out of reach, and will movethe ball to the nearest unoccupied neutral spot when one of the following conditions occurs:
1. the ball remains outside the playing field too long, after a visible and loud count,5
2. any of the robots are unable to return the ball into the playing field (without their wholebody leaving the playing field), or
3. the referee determines that the ball will not come back into the playing field.

2.10 Damaged robots
If a robot is damaged, it has to be taken off the field and must be fixed before it can play again. Even
if repaired, the robot must remain off the field for at least one minute or until the next kick-off is due.6
Some examples of a damaged robot include:●●●

it does not respond to the ball, or is unable to move (it lost pieces, power,etc.).
it continually moves into the goal or out of the playing
field.
it turns over on its own accord.

Computers and repair equipment are not permitted in the playing area during gameplay. Usually, ateam member will need to take the damaged robot to an ”approved repair table” near the playing
area. A referee may permit robot sensor calibration, computers and other tools in the playing area,
only for the 5 minutes before the start of each half. Reprogramming of robots during the gameplay
can only happen when they are out of the game (i.e., damaged or out of bounds), or when explicitly
allowed by the referee.
After a robot has been fixed, it will be placed on the unoccupied neutral spot furthest from the ball,facing its own goal. A robot can only be returned to the field if the damage has been repaired. If thereferee notices that the robot was returned to the field with the same original problem, s/he may ask
the robot to be removed, and proceed with the game as if the robot had not been returned.
Only the referee decides whether a robot is damaged. A robot can only be taken off or returned withthe referee’s permission.
If both robots from the same team are deemed damaged at kick-off, gameplay will be paused and the4

In previous version this said ”any other”

5

usually a count of three, the length of the count could be decided by the OC before a competition as long as it’s the same length within a
sub-league
6

In previous version this said ”If all robots have moved out of bounds, the penalties are discarded and the match resumes with a neutral
kickoff.”

Final Rules as of December 19, 201936

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remain damaged. However, these rules only apply when none of the two robots from the same team
were damaged as the result of the opponent team violating the rules.
Whenever a robot is removed from play, its motors must be turned off.

2.11 Interruption of Game
In principle, a game will not be stopped.
A referee can stop the game if there is a situation on or around the field which the referee wants todiscuss with a tournament official or if the ball malfunctions and a replacement is not readily available.
When the referee has stopped the game, all robots must be stopped and remain on the field
untouched. The referee may decide whether the game will be continued/resumed from the situationin which the game was stopped or by a kick-off.

3 TEAM
3.1 Regulations
A team must have more than one member to form a RoboCupJunior team to participate in theInternational event. A team member(s) and/or robot(s) cannot be shared between teams.
Each team member needs to carry a technical role.
Each team must have a captain. The captain is the person responsible for communication withreferees. The team can replace its captain during the competition. Team is allowed to have at most
two members beside the field during game play: they will usually be the captain and an assistantteam member.

3.2 Violations
Teams that do not abide by the rules are not allowed to participate.
Any person close to the playing field is not allowed to wear any orange, yellow or blue clothes thatcan be seen by the robots (to avoid interference). A referee can require a team member to change
clothes or to be replaced by another team member if interference is suspected.

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Figure 2 Anyone close to the playing field is not allowed to wear orange, yellow or blue clothes

The referee can interrupt a game in progress if any kind of interference from spectators is suspected(color clothing, IR emitters, camera flashes, mobile phones, radios, computers, etc.).
This needs to be confirmed by an OC member if a claim is placed by the other team. A team claimingthat their robot is affected by colors has to show the proof/evidence of the interference.

4 ROBOTS
4.1 Number of robots / substitutions
Each team is allowed to have at most two robots for the full tournament. The substitution of robots
during the competition within the team or with other teams is forbidden.

4.2 Interference
Robots are not allowed to be colored orange, yellow or blue in order to avoid interference. Orange,
yellow, and blue colored parts used in the construction of the robot must either be occluded by otherparts from the perception by other robots or be taped/painted with a neutral color.
The robot must not emit infrared light. However, optical sensors (e.g. infrared-distance-sensors) may
be used as long as they do not affect other robots.
Infrared light reflecting materials must not be used on the outside. If robots are painted, they must be
painted matte. Minor parts that reflect infrared light could be used as long as other robots are notaffected. Robots must not produce magnetic interference in other robots on the field.
Robots must not produce visible light that may prevent the opposing team from playing when placedon a flat surface. Any part of a robot that produces light that may interfere with the opposing robot’s
vision system must be covered.
A team claiming that their robot is affected by the other team’s robot in any way must show the
proof/evidence of the interference. Any interference needs to be confirmed by an OC member if a
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claim is placed by the other team.

4.3
Control
The use of remote control of any kind is not allowed during the match. Robots must be started andstopped manually by humans and be controlled autonomously.

4.4 Communication
Robots are not allowed to use any kind of communication during game play unless the communication
between two robots is via Bluetooth class 2 or class 37 or via any other device that communicatesusing the 802.15.4 protocol (e.g., ZigBee and XBee).
Teams are responsible for their communication. The availability of frequencies cannot be guaranteed.

4.5 Agility
Robots must be constructed and programmed in a way that their movement is not limited to only one
dimension (defined as a single axis). They must move in all directions, for example by turning.
Robots must respond to the ball in a direct forward movement. For example, it is not enough tobasically just move left and right in front of their own goal. It must also move directly towards the ballin a forward movement. At least one team robot must be able to seek and approach the ball anywhereon the field, unless the team has only one robot on the field at that time. The goalie has to approach
the ball in the whole penalty area.
If a robot does not touch the ball that is placed no further than 20 cm from it within 10 seconds, it
is deemed to be damaged (see Damaged Robots).

4.6 Handle
All robots must have a stable and easily noticeable handle to hold and lift them. The handle must be
easily accessible and allow the robot to be picked up from at least 5 cm above the highest structureof the robot.8
The dimensions of the handle may exceed the 22 cm height limitation, but the part of the handle thatexceeds this 22 cm limit cannot be used to mount components of the robot.
7
8

range shorter than 20 meters

In previous version this said ”22 +/- 2 cm of height”

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4.7 Top Markers
A robot must have markings in order to be distinguished by the referee. Each robot must have a white
plastic circle with a diameter of at least 4 cm mounted horizontally on top. This white circle will be
used by the referee to write numbers on the robots using markers, therefore the white circles mustbe accessible and visible.
Before the game, the referee will designate the numbers for each robot and will write them on the
top white circle. Robots not carrying the top white circle are not eligible to play.

Figure 4 A visualization of the top marker

4.8 Additional regulations of the sub-leagues
A tournament may be organized in different sub-leagues. Each sub-league (e.g. Soccer Open and
Soccer Lightweight) has its own additional regulations, including regulations affecting theconstruction of robots. They are outlined in Section 9.

4.9 Violations
Robots that do not abide by the specifications/regulations (see Section 9.2) are not allowed to play,
unless these rules specify otherwise.
If violations are detected during a running game the team is disqualified for that game.
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If similar violations occur repeatedly, the team can be disqualified from the tournament.

5 FIELD
5.1 Kind of field
There is only one kind of field for all sub-leagues.

5.2 Dimensions of the field
The playing field is 122 cm by 183 cm. The field is marked by a white line which is part of the playing
field. Around the playing field, beyond the white line, is an outer area of 25 cm9 width.
The floor near the exterior wall includes a wedge, which is an incline with a 10 cm base and 2 +/- 1 cm
rise for allowing the ball to roll back into play when it leaves the playing field.
Total dimensions of the field, including the outer area, are 182 cm by 243 cm.10

5.3 Walls
Walls are placed all around the field, including behind the goals and the outer area. The height of thewalls is 22 cm. The walls are painted matte black.

5.4 Goals
The field has two goals, centered on each of the shorter sides of the playing field. The inner-space ofthe goal is box-shaped with the following dimensions: 60 cm wide, 10 cm high, and 74 mm deep. It
has a cross-bar on top (to allow checking if the ball scored). The height of the cross-bar is 2 +/- 1 cm.
The goal ”posts” are positioned over the white line marking the limits of the field. The cross-bar is over
the white line. The interior walls and the crossbar of each goal are painted, one goal yellow and theother goal blue. The exterior (including the goal post and frame) is painted black (see Field diagrams).
It is recommended that the blue be a bright shade so that it is different from the black exterior.

5.5 Floor
The floor consists of dark green carpet on top of a hard level surface. All straight lines on the fieldshould be painted and have a width of 20 mm.

9In previous version this said ”30 cm”

10

In previous version this said ”It is recommended that the field be positioned 70 to 90 cm off the ground.”Final Rules as of December 19, 201936

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There are five neutral spots defined in the field. One is in the center of the field. The other four are
adjacent to each corner, located 45 cm along the long edge of the field, aligned with each goal post
towards the middle of the field (from the goal post). The neutral spots can be drawn with a thin black
marker. The neutral spots ought to be of circular shape measuring 1 cm in diameter.

5.7 Center circle
A center circle will be drawn on the field. It is 60 cm in diameter. It is a thin black marker line. It isthere for Referees and Captains as guidance during kick-off.

5.8 Penalty areas
In front of each goal there is a 25 cm11 wide and 70 cm12 long penalty area.
The penalty areas are marked by a white13 line of 20 mm width. The line is part of the area.14

5.9 Lighting and Magnetic Conditions
The organizers will do their best to limit the amount of external lightning and magnetic interference.
However, the robots need to be constructed in a way which enables them to work under conditions
that are not perfect (i.e. by not relying on compass sensors or specific lightning conditions).15

FIELD DIAGRAMS

11
12
13
14
15

In previous version this said ”30 cm”
In previous version this said ”90 cm”
In previous version this said ”black”
In previous version this said ”A robot is considered inside the Penalty Area when it is completely inside.”

In previous version this said ”The fields should be placed in a way that the influence by external infrared light is as low as possible andthat the magnetic field of the earth is disturbed as little as possible. Perfect conditions cannot be guaranteed, however. Teams must cometo tournaments being prepared to calibrate their robots based on the lighting and magnetic conditions at the venue.”

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6 BALL
6.1 Specification for Soccer Lightweight Ball
See Appendix A.

6.2 Specification for Soccer Open Ball
See Appendix B.

6.3 Tournament balls
Balls for the tournament must be made available by the organizers. Organizers are not responsible forproviding balls for practice.

7 CODE OF CONDUCT
7.1 Fair PlayIt is expected that the aim of all teams is to play a fair and clean game of robot soccer. It is expectedthat all robots will be built with consideration to other participants.
Robots are not allowed to cause deliberate interference with or damage to other robots during normal
game play.
Robots are not allowed to cause damage to the field or to the ball during normal game play.
A robot that causes damage may be disqualified from a specific match at the referee’s discretion. In
addition, the OC will be informed.
Humans are not allowed to cause deliberate interference with robots or damage to the field or theball.

7.2 Behavior
All participants are expected to behave themselves. All movement and behavior is to be of a subdued
nature within the tournament venue.

7.3 Help
Mentors (teachers, parents, chaperones, and other adult team members including translators) are not
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allowed in the student work area unless it is explicitly, but temporarily, permitted by a member of theOrganizing Committee. Only participating students are allowed to be inside the work area.
Mentors must not touch, build, repair, or program any robots.

7.4 Sharing
The understanding that any technological and curricular developments should be shared among the
RoboCup and RoboCupJunior participants after the tournament has been a part of world RoboCup
competitions.

7.5 Spirit
It is expected that all participants, students, mentors, and parents will respect the RoboCupJuniormission.
It is not whether you win or lose, but how much you learn that counts!

7.6 Violations / Disqualification
Teams that violate the code of conduct can be disqualified from the tournament. It is also possible todisqualify only single person or single robot from further participation in the tournament.
In less severe cases of violations of the code of conduct, a team will be given a warning by showing ita yellow card. In severe or repeated cases of violations of the code of conduct a team can bedisqualified immediately without a warning by showing it the red card.

8 CONFLICT RESOLUTION
8.1 Referee and referee assistant
The referee is a person in charge of making decisions with regards to the game, according to theserules, and may be assisted by a referee assistant.
During gameplay, the decisions made by the referee and/or the referee assistant are final.
Any argument with the referee or the referee assistant can result in a warning. If the argument
continues or another argument occurs, this may result in immediate disqualification from the game.
Only the captain has a mandate to freely speak to the referee and/or their assistant. Shouting at areferee and/or their assistant, as well as demanding a change in ruling can be directly penalized by awarning at the referee’s discretion.
At the conclusion of the game, the result recorded in the scoresheet is final. The referee will ask the
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will be reviewed by the OC members.

8.2 Rule clarification
Rule clarification may be made by members of the RoboCupJunior Soccer Technical Committee andOrganizing Committee, if necessary even during a tournament.

8.3 Rule modification
If special circumstances, such as unforeseen problems or capabilities of a robot occur, rules may be
modified by the RoboCupJunior Soccer Organizing Committee Chair in conjunction with available
Technical Committee and Organizing Committee members, if necessary, even during a tournament.

8.4 Regulatory statutes
Each RoboCupJunior competition may have its own regulatory statutes to define the procedure of thetournament (for example the SuperTeam system, game modes, the inspection of robots, interviews,
schedules, etc.). Regulatory statutes become a part of this rule.

9 LEAGUE REGULATIONS
9.1 Preamble
According to rule 3.8 of the RoboCupJunior Soccer Rules, each league has its own additional
regulations. They become a part of the rules.

For RoboCupJunior 2020, there are two sub-leagues as follows:16●●

Soccer Lightweight
Soccer OpenAll team members need to be within the minimum and maximum age as specified in the
RoboCupJunior General Rules which can be found at http://junior.robocup.org/robocupjuniorgeneral-rules/.
As described in Section 6.1 and Section 6.2, the matches in the Soccer Open sub-league are conductedusing a passive ball, whereas the matches in the Soccer Lightweight sub-league are played using the16

biggest differences are described in 8.2.1 Dimensions

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IR ball.

9.2 Regulations
9.2.A Dimensions
Robots will be measured in an upright position with all parts extended. A robot’s dimensions must
not exceed the following limits:[1] The handle and the top markers of a robot may exceed the height.
[2] The weight of the robot includes that of the handle[3] We encourage teams to include protection circuits for lithium-batteries. Voltage limits relate to
the nominal values, vediations at the power pack due to the fact that charged will be tolerated.
[4] The technical committee intends to make the diameter/height of robots in the Open subleague to be 20 cm in 2021, with further decrease to 18 cm in 2022 onwards. Similarly, theweight limit will be 2300 g in 2021, with further decrease to 2200 g in 2022.
The ball-capturing zone is defined as any internal space created when a straight edge is placed on
the protruding points of a robot. This means the ball must not enter the concave hull of a robot by
more than the specified depth. Furthermore, it must be possible for another robot to takepossession of the ball.
9.2.B Limitations
A single robot can only use one camera. All commercial omnidirectional lenses/cameras are notpermitted. Only omnidirectional lenses/cameras made by students are permitted, meaning that theirconstruction needs to be primarily and substantially the original work of a team. Teams using themon their robots must prove how they made them on their presentation poster and at an interview. For
the purpose of these rules, omnidirectional is defined as having a field-of-view of more than 140
degrees horizontally and more than 80 degrees vertically (these values reflect the optical system of
the human eye).
Voltage pump circuits are permitted only for a kicker drive. All other electrical circuits inside therobot cannot exceed 15.0 V for Soccer Open and 12.0 V for Soccer Lightweight. Each robot must be
designed to allow verifying the voltage of power packs and its circuits, unless the nominal voltage is
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Pneumatic devices are allowed to use ambient air only.
Kicker strength is subject to compliance check at any time during the competition. During gameplay,a referee can ask to see a sample kick on the field before each half, when a damaged robot is returnedto the field, or when the game is about to be restarted after a goal. If the referee strongly suspects
that a kicker exceeds the power limit, s/he can require an official measurement with the ’Kicker Power
Measure Device’. (See Appendix C for more details.)
9.2.C Construction

For the construction of a robot, any robot kit or building block may be used as long as the design andconstruction are primarily and substantially the original work of a team. This means that commercial
kits may be used but must be substantially modified by the team. It is neither allowed to mainly follow
a construction manual, nor to just change unimportant parts.
Indications for violations are the use of commercial kits that can basically only be assembled in one
way or the fact that robots from different team(s), build from the same commercial kit, all basicallylook or function the same.
Robots must be constructed in a way that they can be started by the captain without the help ofanother person.
Since a contact with an opponent robot and/or dribbler that might damage some parts of robots
cannot be fully anticipated, robots must have all its active elements properly protected withresistant materials. For example, electrical circuits and pneumatic devices, such as pipelines andbottles, must be protected from all human contact and direct contact with other robots.

When batteries are transported or moved, it is recommended that safety bags be used. Reasonable
efforts should be made to make sure that in all circumstances robots avoid short-circuits and chemical

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or air leaks.

9.2.D Programming
Robots must be programmed exclusively by student members of the team. Mentors, teachers,
parents or companies should not be involved in the programming and debugging of robots.
For the programming of the robots, any programming language, interface or integrated development
environment (IDE) may be used. The use of programs that come together with a commercial kit(especially sample programs or presets) or substantial parts of such programs are not allowed. It is notallowed to use sample programs, not even if they are modified.
9.2.E Inspections
Robots must be inspected and certified every day before the first game is played. The Organizing
Committee may request other inspections if necessary, including random inspections which may
happen at any time. The routine inspections include:●●●●

Weight restrictions for the particular sub-league (see Section 9.2.A).
Robot dimensions (see Section 9.2.A).
Voltage restrictions (see Section 9.2.A and Section 9.2.B).
Kicker strength limits, if the robot has a kicker (see Appendix C).

Proof must be provided by each team that its robots comply with these regulations, for example, by adetailed documentation or log book. Teams may be interviewed about their robots and thedevelopment process at any time during a tournament.
See an example of the inspection sheet that members of the OC will use in Appendix D. Note that the
sheet will be updated by OC members before the competition to match this year’s rules, but theimportant aspects which are checked will stay the same.

10 INTERNATIONAL COMPETITION
10.1 Team
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Maximum team size is 4 members for RoboCupJunior 2020.
Starting in 2017, Soccer Lightweight team members can participate in the World Championship only
twice. After their second participation, they need to move to Soccer Open. Note that counting starts
with the 2017 World Championship.

10.2
Interviews
During the international competition, the Organizing Committee will interview teams during the Setup
Day of the event. This means that the teams need to be already present early on this day. Teams mustbring robots, the code that is used to program them and any documentation to the interview.
During an interview, at least one member from each team must be able to explain particularities about
the team’s robots, especially with regards to its construction and its programming. An interviewer may
ask the team for a demonstration. The interviewer may also ask the team to write a simple program
during the interview to verify that the team is able to program its robot.
All teams are expected to be able to conduct the interview in English. If this poses a problem, the team
may ask for a translator to be present at the interview. If the OC is not able to provide a translator,
the team is required to do so. During the interview, the team will be evaluated using so-called Rubrics,
which are published on the website mentioned in the beginning of these rules.
The Technical Committee recommends the implementation of interviews in regional competitions as
well, but this is not mandatory.

10.3 Technical Challenges
Inspired by the major leagues and the need for further technological advancement of the leagues,
the Technical Committee has decided to introduce so called Technical Challenges.
The idea of these challenges is to give the teams an opportunity to show off various abilities of theirrobots which may not get noticed during the regular games. Furthermore, the Technical Committee
envisions these challenges to be a place for testing new ideas that may make it to the future rules, orotherwise shape the competition.
Any RoboCupJunior Soccer team will be eligible to try to tackle these challenges. Unless otherwise
stated, any robot taking part in these challenges needs to abide by these rules in order to successfullycomplete it.
10.3.A Precision shooter

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The results in soccer are evaluated by the number of scored goals. History usually does not care how
they were scored. For the spectators, however, this usually makes all the difference.
This challenge consists of six rounds. In each round, the robot starts from its own penalty area oriented
towards the goal. The ball is placed randomly (by rolling a die) inside this half of the field on one of
the following spots:
1.
2.
3.
4.
5.
6.

Left neutral spot
Right neutral spot
Left corner of the penalty area
Right corner of the penalty area
Left corner of the field
Right corner of the field

Figure 5 Partitioning of the goal into 6 parts.

The robot needs to locate the ball and score a goal while staying on its own half of the field. Eachround takes at most 20 seconds.
●●●

The team is free to pick from which side to kick.
The same robot must be used for all
rounds.
The robot must stay on its half of the field for the goal to count, but ”out of bounds” rules do
not apply.

Initially, the opposite goal is completely open (see Figure 5). After each scored-goal, a member of theteam rolls a die and the part of the goal that corresponds to the number on the dice will be covered
with a black box. If this part of the goal is already covered, the die will be rolled again. See Figure 6,
where the number 3 and number 5 were rolled on a die after each round and the respective parts ofthe goal are covered. Note that if number 3 or 5 will get rolled in the next rounds, a new roll of a die
will follow.
The result of this challenge is the number of scored goals.

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Figure 6 An example state of the goal after two rounds

10.4 Penalty Kick
A penalty kick takes place after a grave offense happens.
The kicking procedure consists of the following steps:
1. All robots as well as the ball are removed from the field.
2. The offending (”kicking”) team places a robot inside its own penalty area, rotated towards
its own goal. A ball is placed at the central neutral spot.
3. The offending (”kicking”) team turns their robot on. The robot needs to stay still for the next
5 seconds.
4. During these 5 seconds the defending team places a robot which is turned off inside its own
penalty area.
5. In order to score a goal, the offending team’s robot needs to move the ball inside theopponents goal. It needs to do so in at most 15 seconds and while staying within the centercircle once it touches the ball.
If the offending team’s robot moves before the 5 seconds pass, the result is automatically no goal.
Once the penalty kick finishes, the game continues with a Section 2.3, with the defending teamkicking-off.

10.5 Further information on International Competition
All teams qualified for the international competition must share their designs, both hardware andsoftware, with all present and future participants. These teams are also required to send a digital
portfolio before the competition. Further details on how will be provided by the Organizational
Committee.
During the competition days of the International Competition (as well as before the event) the teammembers are responsible for checking all relevant information published by the Soccer Organizational
Committee, General Chairs, or any other RoboCup official.
Teams competing in the International Competition can receive awards for their performance. Theseawards are decided and introduced by the Organizational Committee, which publishes all necessary
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robot design, team spirit, and individual games.
Note that as stated in Section 7.5, it is not whether you win or lose, but how much you learn thatcounts!

10.6 Intro League
In order to help newcomers experience the RoboCupJunior Soccer competition, the TC would liketo encourage local and/or regional competitions to introduce and offer a so called ”Intro League”.
Although such a league will not be part of the international competition, the TC believes that it isworthwhile to make it part of regional and super-regional competitions. Each regional and superregional competition could have its specific rules but the TC would like to suggest they contain thefollowing:

●
●
●

●
●

●

The Intro League should be based on the RoboCupJunior Soccer rules.
Only competitors that did not previously participate in an international (that is not a
regional or super-regional) competition are allowed to take part.
It may be worth creating two sub-leagues: a 2v2 sub-league where two robots from one
team play against two robots from the other, and a 1v1 sub-league where both teams playwith just one robot.
The Intro League should ignore the Out of Bounds rule. When robots go out of bounds, thereferee should put them back in.
The robots should be created from a commercial robot kit(s) widely available in a specificregion, except for sensors necessary for robots to be able to find the ball (i.e. ball detector)
and the orientation of the field (i.e. compass). (see the sample Intro League rules below)
The robots should be limited in size to 22.4cm by 22.4cm by 22.4cm (all measurements +/1cm ). There shall be no weight limit.

Sample Intro League rules already in use can be found on the links below:●●

https://robocupjunior.org.au/sites/default/files/Official%20RCJA%20Standard%20Soccer%2
0Rules%202019%20%28SLTC
https://rcj2019.eu/sites/default/files/Soccer%2011%20Standard%20Kit%20Rules%202019%20Final.pdf

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A Technical Specification for pulsed Soccer Ball
1.1 Preamble
Answering to the request for a soccer ball for RCJ tournaments that would be more robust tointerfering lights, less energy consuming, and mechanically more resistant, the RCJ Soccer TechnicalCommittee defined the following technical specifications with the special collaboration from EK Japanand HiTechnic.
Producers of these balls must apply for a certification process upon which they can exhibit the RCJcompliant label and their balls used in RCJ tournaments.
Balls with these specifications can be detected using specific sensors from HiTechnic (IRSeeker information on distance and angle) but also common IR remote control receivers (TSOP1140,
TSOP31140, GP1UX511QS, etc. - on-off detection with a possible gross indication of distance).

1.2 Specifications
1.2.A IR light
The ball emits infra-red (IR) light of wavelengths in the range 920nm - 960nm, pulsed at a square-wave
carrier frequency of 40 KHz. The ball should have enough ultra-bright, wide angle LEDs to minimize
unevenness of the IR output.
1.2.B Diameter
The diameter of the ball is required to be 74mm. A well-balanced ball shall be used.
1.2.C Drop Test
The ball must be able to resist normal game play. As an indication of its durability, it should be able
to survive, undamaged, a free-fall from 1.5 meters onto a hardwood table or floor.
1.2.D Modulation
The 40 KHz carrier output of the ball shall be modulated with a trapezoidal (stepped) waveform of
frequency 1.2 kHz. Each 833-microsecond cycle of the modulation waveform shall comprise 8 carrier
pulses at full intensity, followed (in turn) by 4 carrier pulses at 1/4 of full intensity, four pulses at 1/16
of full intensity and four pulses at 1/64 of full intensity, followed by a space (i.e. zero intensity) of
about 346 microseconds. The peak current level in the LEDs shall be within the range 45-55mA. The
radiant intensity shall be more than 20mW/sr per LED.

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If the ball has an embedded rechargeable battery, when new and fully charged it should last for morethan 3 hours of continuous use before the brightness of the LEDs drops to 90% of the initial value. If
the ball uses replaceable batteries, a set of new high-quality alkaline batteries should last for morethan 8 hours of continuous use before the brightness of the LEDs drops to 90% of the initial value.
1.2.F Coloration
The ball must not have any marks or discoloration that can be confused with goals, or the field itself.
1.3 Official suppliers for pulsed balls
Currently, there is one ball that has been approved by the RoboCupJunior Soccer TechnicalCommittee:●

RoboSoccer ball operating in MODE A (pulsed) made by EK Japan/Elekit (https://elekit.co.jp)

Note that this ball was previously called RCJ-05. While you may not be able to find a ball with thisname anymore, any IR ball produced by EK Japan/Elekit is considered to be approved by the TC.

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B Technical Specification for passive Soccer Ball
2.1 Preamble
In order to push the state of the art in the Soccer competition forward, the RCJ Soccer TechnicalCommittee has defined the following technical specifications for the ”passive” ball. The chosen values
and characteristics reflect the desire of the Technical Committee to make sure that the selected ballis not fundamentally different from the IR ball that was used before, and that it is close to balls usedin the Soccer leagues in the Major category, where the Junior competitors may continue to compete
once they pass the age limits.
The Technical Committee has been able to identify two balls that meet the technical specifications
outlined below and are available worldwide. None of these balls have been marked official. Thatmeans it is not guaranteed that one of these balls will be used at the international event. However,
the official ball will not be much different. These balls are:
1. https://www.schweikert-hundesport.de/index.php/en/Ball%2C-orange%2C-hollow%2C-plastic/c-220910/a-93011
Note that since the e-shop may also send you a semi-glossy ball by mistake, it is safer tomention that you would like to receive a matte ball when finishing your order or in an email
after you finish it.
2. https://www.amazon.com/Mylec-Weather-Bounce-Hockey-Orange/dp/B002LBDA30
The Technical Committee found the first ball preferable, as the second one might reflect light tosome extent (for instance from camera flashes).

2.2 Specifications
2.2.A Diameter
The diameter of the ball is required to be 65mm +- 5mm. A well-balanced ball shall be used.
2.2.B Drop Test
The ball must be able to resist normal game play. As an indication of its durability, it should be able
to survive, undamaged, a free-fall from 1.5 meters onto a hardwood table or floor.
2.2.C Coloration
The ball shall be of orange color. Since the definition of the orange color in general is not easy, anycolor that a human would deem to be orange and is substantially different from the other colors usedon the field is acceptable. There should be no distractive markings on the ball.
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The surface of the ball shall be smooth and matte. Engravings on the ball’s surface are tolerated. Theball should not reflect light. The inside of the ball should be hollow.
2.2.E Weight
The ball should be no heavier than 80 grams and no lighter than 60 grams.

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C Kicker Power Measuring Device
All robot kickers will be tested with the ball used in the sub-league they participate in.

3.1 Preamble
This Kicker Power Measuring Device can measure the power of a robot’s kicker. It is easy to buildwith commonly accessible materials.
This device can measure the power of a robot’s kicker up to a length of 22cm.

3.2 Materials

3.3 Device schematics
The device schematics can be printed out from the diagram located at the end of the document. Pleasebe advised to check that the software you use to print the schematic does not have a scale to fit option
activated (i.e. check that it is configured to print at 100% or actual size scale).
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3.4 Example of device construction
a.
b.
c.
d.

Print out the device schematics.
Paste the paper on a plastic board. The inclined line (red lines) should be straight.
Cut out along the lines, and drill the holes.
The two boards should be connected using the 40mm spacers.

3.5 Inspection
a. Place a ball at the bottom of the ramp run of the device and put the robot in front of theball, aiming the kicker towards the top of the ramp.
b. Activate the robot’s kicker for a single shot.
c. Measure the distance that the ball traveled on the device. The distance should not exceed
22 cm.

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D Inspection sheet example

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