RoboCup Junior (RCJ), sometimes stylised RobocupJunior, is a division of RoboCup, a not-for-profit robotics organisation. It focuses on education and aims to introduce the larger goals of the RoboCup project (creating robots) to primary and secondary school aged children (technically up through age 19). Participants compete in one of three main leagues: Soccer, Rescue or Dance. Dance Theatre also exists as a sub-league of Dance, and Premier Rescue is part of the competition in Australia.
RoboCup Junior was invented and started back in 1998 with a demonstration held by Henrik Hautop Lund and Luigi Pagliarini  at the RoboCup international competition held in Paris, France. In 1999, an interactive workshop and competition was held by Henrik Hautop Lund and Luigi Pagliarini  at the RoboCup international competition in Stockholm, Sweden. The following year in 2000, the first international RoboCup Junior competition was held in Melbourne, Australia.
Then-prime minister of Australia, John Howard, was impressed in 2001 when he visited students competing in a RoboCup Junior Australia competition, congratulating both teachers and students for their accomplishments.
Each year, an international competition is run around the same time, and at the same location, as the RoboCup competition. The location changes each year, and in the past has seen events held at:
- 2000 - Melbourne, Victoria, Australia 
- 2001 - Seattle, Washington, United States of America
- 2002 - Fukuoka, Japan
- 2003 - Padova, Italy
- 2004 - Lisbon, Portugal
- 2005 - Osaka, Japan
- 2006 - Bremen, Germany
- 2007 - Atlanta, Georgia, United States of America
- 2008 - Suzhou, China.
- 2009 - Graz, Austria.
- 2010 - Singapore.
- 2011 - Istanbul, Turkey.
- 2012 - Mexico City, Mexico.
- 2013 - Eindhoven, the Netherlands.
- 2014 - João Pessoa, Brazil.
- 2015 - Hefei, China
- 2016 - Leipzig, Germany
- 2017 - Nagoya, Japan
- 2018 - Montreal, Canada
Besides the international competition there are national and regional competitions around the world. Often teams have to qualify at their local competition to be admitted to the world championship. For example, in Germany, where RoboCup Junior is very popular, teams start on one of several qualification tournaments with over 300 teams, before advancing to the German Open and finally, the World Championships.
Two teams each place two robots (which they have designed and created) on a playing field. The aim of the game is for each team of robots to play a fully autonomous game of soccer. The robots detect the infrared-emitting ball and use this as well as other specialised sensors, such as sonars, compasses and cameras to locate themselves and the opposition's goal. These robots must each be able to fit into a cylinder which is 220 mm in diameter and height.
Originally, the soccer field had a grayscale plastic floor allowing the robots to locate themselves along the field. In 2007, this was replaced with the GENII (Generation 2) field which had different shades of green plastic, which allowed light sensors to be used to more accurately determine location (this field is still used in Australia and is now also used in the World Robot Olympiad). In 2009, the field was replaced with plain green felt. This change was aimed at making the game more realistic by creating greater reliance on the goal location and walls rather than the ground. The change, however, has been controversial with many teams having problems with quality of the felt.
When RoboCup Junior was first formed, almost all teams used Lego Mindstorms construction kits to build their robots. In more recent years, especially at the World Championships, some teams have been using more advanced technology and designs in their robots. Custom printed circuit boards, actuator devices (for kicking), cameras and advanced micro controllers have become common place at the international competition.
Since inception, the rescue challenge has gone through a number of iterations, increasing in difficulty. A map of Australia was used to demo the rescue challenge initially (and was subsequently used in Australia for a number of years). Subsequently, this was changed to a number of white tiles with black lines marked on them, which the robot had to follow. Internationally, this was replaced with a set of "rooms" that the robot had to search and move through by following a line. In 2011 this was replaced with a new competition without lines where the robot had to detect heat-emitting "victims".
Premier Rescue challenge
Premier Rescue is practiced in the Australian RoboCup Junior competition. It is very similar to the Australian Rescue challenge except for some minor additions. The teams must capture the object within the marked area and place it on a platform. This is more difficult than the regular Australian Rescue challenge because the participants must construct a device to secure the object and lift it onto the platform.
A team creates both a robot and a dance composition. The aim of the competition is to create a two-minute dance performance choreographed to music; with particular attention going to construction and programming. Team members can join in to dance alongside the robot. A panel of judges decides the winner based on a number of different criteria. The dance competition is most popular amongst younger students, mostly of primary school ages. The robots range in size from 10 cm tall to 2/3 meters tall with intricate mechanical details.
Dance Theatre challenge
In Dance Theatre, teams build and program robots that act out a story-based song. For example, robots could be different characters featured in it. This section of RoboCup Junior is more difficult than Dance, as the robots must complete more specialised actions.
- Official website
- Lund, Henrik Hautop; Arendt, Jens Aage; Fredslund, Jakob; Pagliarini, Luigi (1999). "Ola: What Goes Up, Must Fall Down". Journal of Artificial Life and Robotics. 4 (1). CiteSeerX 10.1.1.33.7637.
- "RoboCup Junior 2001 Promotional Flier" (PDF). RoboCup Junior 2001 Committee. Retrieved 2007-04-22.
- Lund, Henrik Hautop; Pagliarini, Luigi. "RoboCup Jr. with LEGO Mindstorms" (PDF). Proceedings of International Conference on Robotics and Automation (ICRA2000), New Jersey: IEEE Press, 2000. Retrieved 2013-07-09.
- "RoboCupJunior Australia impresses Australian Prime Minister". The RoboCup Federation. 2001-03-30. Archived from the original on 2007-03-12. Retrieved 2007-04-22.
- "Queen Elizabeth II saw RoboCupJunior in Australia". The RoboCup Federation. February 2002. Archived from the original on 2007-03-12. Retrieved 2007-04-22.
- "RoboCup Junior 2000 Official Website". RoboCup Junior 2000 Committee. Retrieved 2007-04-22.
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- "RoboCup Junior 2002 Official Website". RoboCupJunior 2002 Committee. Archived from the original on 2005-11-09. Retrieved 2007-04-22.
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- "RoboCupJunior 2004 Official Website". RoboCup Junior 2004 Committee. Retrieved 2007-04-22.
- "RoboCup Junior 2005 Official Website". RoboCup Junior 2005 Committee. Retrieved 2007-04-22.
- "RoboCup Junior 2006 Official Website". RoboCupJunior 2006 Committee. Retrieved 2007-04-22.
- "RoboCup Junior 2007 Official Website". RoboCup Junior 2007 Committee. Retrieved 2007-04-22.
- "RoboCup World Championship Games". The RoboCup Federation. Archived from the original on 2007-02-23. Retrieved 2007-04-22.
- "RoboCup 2009". TU Graz. Retrieved 2009-06-19.
- "RoboCup 2010". The RoboCup Federation. Retrieved 2010-06-19.
- "RoboCup 2011". The RoboCup Federation. Archived from the original on 2010-06-19. Retrieved 2011-07-20.
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- "Robocup 2014". The Robocup Federation. Retrieved 2014-10-11.