Call for Participation

Call for Participation
RoboCup 2021

Virtual Humanoid Soccer Competition and
Virtual Humanoid Research Demonstration

June 22nd to June 28th, 2021


The RoboCup Humanoid League is inviting interested teams to apply for participation in the RoboCup 2021 Virtual Humanoid League competitions.

The Humanoid League will host competitions in the following categories:

  • Virtual Humanoid Soccer Competition (HSC)
    • KidSize: 40 – 100cm robot height (FIFA size 1 ball)
    • AdultSize: 100 – 200cm robot height (FIFA size 5 ball)
  • Virtual Humanoid Research Demonstration (HRD)

For more detailed class definitions and more information about the humanoid league, please refer to the humanoid league home page at and join the humanoid league mailing list at:

1. Virtual Humanoid Soccer Competition (HSC)

A virtual soccer competition will be organized to resemble the physical humanoid soccer competition as closely as possible, both in terms of the realism of the provided game environment as well as the rules of the game. 

Since the Virtual Humanoid Soccer Competition will be held entirely online, all teams registering for the competition will be admitted. In case of a sufficient number of qualified teams, the sub-leagues (KidSize and/or AdultSize) will be divided into League A and League B. The exact method of seeding applied will be announced closer to the competition.

Details on the setup and implementation have been published on the RoboCup Humanoid League website. Please note that these documents are still continuously updated.

1.1. Simulator & Game Rules 

Webots will be used as a stimulator for the Virtual Humanoid Open Competition. The final game environment, including a model of the artificial turf, as well as a demo robot model with backlash in the motors, has already been released on the humanoid league website. Both the game environment as well as the robot model are developed to resemble the real world as closely as possible to allow for sim2real learning in the years to come. While teams are allowed to compete with the standard robot model, they are encouraged to develop their own robot model, which needs to be submitted and checked in accordance with the game rules. Details are described in Section 1.4.

The rules of the virtual game are set up to follow the rules of the 2020 RoboCup Humanoid rule book as closely as possible. A draft of the rules has already been published on the humanoid league website. Please note that changes to the rule book may be made until mid of April, at which point we will release a final version of the rule book for the virtual games. The laws of the game will be enforced by an autonomous refereeing system (AutoRef), which will be released April 26th (tentative date).   

1.2. Competition Setup 

The competition will be performed entirely in the cloud according to a scheme closely resembling that of a physical Humanoid Soccer Competition. Hence, teams will play a number of round robin games followed by knock-out matches to determine the winner of the tournament. The exact game scheme will be announced once the number of participating teams in each size class has been determined. 

Teams are allowed to change their software code throughout the tournament – however, they need to submit the software for the next game latest two hours before their next scheduled match (details on how the software needs to be submitted will be communicated closer to the tournament). The simulation will then be run in the cloud and a video of the match streamed online afterwards. Access to log files will only be provided to teams after the match has been streamed. 

Each robot (up to four in KidSize and two in AdultSize per team) will receive their own instance with an Intel Cascade Lake with 4 vCPU and a Nvidia Tesla T4 GPU (or similar in performance). As in a physical competition, robots need to utilize the network to communicate with other robots in their own team. Similarly, all game decisions will be communicated to the robots over the network via the GameController. 

Teams will be given two possibilities to test the setup of the competition: (1) A mock-competition is scheduled to take place June 4th to June 6th. Teams need to register to the mock-competition in advance (more details will be provided later) and will receive a number of time slots for testing their software setup on the competition instances. (2) During the two setup days of the RoboCup world championship, teams can sign up for spots on the competition instances to test their software. Similar to a regular tournament, teams will also be able to sign-up for using the competition instances each tournament day after the scheduled matches are over. 

1.3. Registration 

The registration process for the Virtual Humanoid Soccer Competition is two-folded. First, you need to submit general data about your team via the submission system of the Humanoid League. Since all teams are automatically qualified to participate, you will receive the letter of qualification together with a code that you need for the registration with the RoboCup Federation. For more details on the registration process and fee, see the website of the 2021 RoboCup competition.

For registering a team for the Virtual Humanoid Soccer Competition, the following data is required:

  • Team name
  • URL of the team’s home page
  • Name of team leader or team contact person
  • E-mail address of team leader or contact person
  • Postal address of the team, team leader or contact person
  • Competition category: Humanoid Soccer Competition KidSize or AdultSize

Please note that teams applying for participation in several classes must register individually for each class and pay the appropriate registration fee. 

The registration form must be filled out online at

1.4. Submission of Robot Model File

Initial requirements for the robot models have been published by the Technical Committee and can be found on the Humanoid League website. Please note that the released document is still preliminary and some minor changes may be made within the next weeks. Teams need to provide robot model files ahead of the tournament to allow the Technical Committee to check whether it is according to the laws of the game. Teams who do not have their own robot model or who would like to attempt playing with the model of another team have the possibility to use the robot models published open source by other teams.

A first version of the robot model needs to be submitted by April 23rd via the submission system of the league. Teams will then be assigned robot models of two other teams to peer-review. Reviewing other team’s robot models is considered obligatory for teams applying to participate in the Humanoid Soccer Competition and failure to provide an adequate review in a timely manner will have consequences for the teams own qualification status. An updated version of the robot model needs to be submitted by May 23rd. Later changes to the robot model file need to be sent to the Technical Committee with a written statement of what has changed and why the change is required. 

Teams are highly encouraged to make their robot model available to the research community with an open-source license. This is, however, not a requirement for participation. In order for the Technical Committee to ensure the robot models being according to the laws of the game, the full robot file needs to be made available to the Technical Committee during the qualification process.

2. Humanoid Research Demonstration (HRD)

The RoboCup Humanoid League invites the research community to apply for showcasing the latest research and development results that are relevant for humanoid robots, during the virtual Humanoid League 2021. Researchers are invited to submit their demonstrations independently of whether they participate in the RoboCup competitions, symposium or have a RoboCup team. Contributions will be evaluated for scientific and technical excellence. 

2.1. Topics of Interest

We welcome demonstrations containing new ideas, concepts, practical studies, and experiment demonstrations relevant to the field of Humanoid Robotics. This year, the special theme of the Humanoid Research Demonstration is sim2real learning and we particularly invite teams to showcase their research in this area. Other topics of interest include, but are not limited to:

  • Components, joints and mechanics;
  • Soft robotics;
  • Anthropomorphic vs. non-anthropomorphic;
  • Walking, running, jumping and other humanoid locomotion;
  • Adaptability and scalability;
  • Sensors and perception;
  • Control and stability;
  • Dealing with falling;
  • Reflexes and learning;
  • Energy supply and efficiency;
  • Robot design and robotic kits;
  • Virtual robots and simulation;
  • Benchmarking;
  • Bipedal robots applied to real problems;
  • Education with and for humanoid robots.

2.2. Virtual Setup

The Humanoid Research Demonstration will take place in one or several virtual sessions and participating teams are asked to stream their demonstration live during the session. As a back-up solution, each team needs to provide a video demonstration prior to the beginning of the tournament. Each demonstration slot will be followed by a time for open discussions in individual groups with the researchers. 

2.3. Application

We invite teams to apply to participate in the Humanoid Research Demonstration by submitting the following material:

2.3.1. Demonstration Data

  • Demonstration title;
  • URL of the group’s home page;
  • Name of the contact person;
  • E-mail address of the contact person;
  • Postal address of the contact person.

2.3.2. Demonstration Video

The first part of the material is a video of your robot or robotic part demonstrating its skills or a brief overview of the software demonstration if your demonstration does not involve a physical embodiment.

The video must be supplied as a link to it via YouTube. The maximum duration of the video is 3 minutes. The proponent is responsible to ensure that the video adheres to YouTube’s TOS (especially in regards to music copyright) to prevent the video from being blocked for the reviewers. 

2.3.3. Hardware Specification

If the demonstration includes any type of hardware to be showcased, a one-page specification (PDF) for each different type of humanoid type robot/mechanism used that includes the following:

  • Robot/mechanism picture;
  • Robot/mechanism name;
  • Size of the humanoid type robot/mechanism;
  • Weight of the robot/mechanism;
  • Robots/mechanisms joint specification;
  • Type of sensors used (incl. type of camera(s));
  • Computing unit(s);
  • Other specifications

2.3.4.  Short paper 

A short paper describing the robot, robot part of software and its task and required environment, limited to four (4) pages including text, references, tables, and figures.

The short paper must follow the LNCS format which can be downloaded from Please pay special attention to the “Author guidelines” that you’ll be able to find there.

2.4. Registration

If your team was qualified to participate in the Humanoid Research Demonstration, you will receive a letter of qualification together with a code that you need for the registration with the RoboCup Federation. For more details on the registration process and fee, see the website of the 2021 RoboCup competition.

Please note that teams applying for participation in several classes must register individually for each class and pay the appropriate registration fee. 

3. Submission System

All application material (both for the Humanoid Soccer Competition and Humanoid Research Demonstration) must be submitted online at The submission system is open for new applications and will close on April 12th.

4. Deadlines

Deadline for submission: April 12th, 2021

Initial submission of robot model file (HSC only): April 23rd, 2021

Updated submission of robot model file (HSC only): May 23rd, 2021

5. Publication

Please note that after the announcement of the qualified teams the qualification material of the qualified teams will be made publicly available. Teams applying for participation therefore grant the right of publication of their qualification material to the humanoid league.

6. RoboCup fee waiver for new teams

The RoboCup Federation is pleased to introduce a waiver of the team fee for the 2021 international RoboCup competition for NEW teams in the major leagues. A NEW team is defined as a team all of whose team members have never participated in an annual international RoboCup competition. The waiver concerns only the team fee and does not imply any waiver of fees for team members.

With best regards,
Technical Committee of RoboCup Humanoid League 2021