NXT/EV3 SumoBot Competition

STEMpalooza dates: December 18th and 19th 2019

See Master Schedule on STEMpalooza web page for time slots

Click here to register for this event

Location: Glazer Children's Museum

The Lego SumoBots Challenge is one of the four STEMpalooza competitions.  Schools may send more than one SumoBot team, consisting of 4 students.  Each team must have its own robot.  Those students are to be a combination of 4th and/or 5th grade students.

If students will be competing in more than one STEMpalooza event, it is the school's responsibility to schedule their event dates and times as to not overlap another competition.  Keep in mind that different events may have various start/end times and how this will affect student supervision at the venue.


Click here for the media release checksheet (please bring to the event for each team).  Click here for district media release.


SumoBots can be built using either a Lego Mindstorms NXT robotics kit, or a Lego Mindstorms EV3 robotics kit.  Kits should not be combined.

A SumoBot must be built using only the pieces found in a base NXT or EV3 kit.  SumoBots cannot contain other outside materials (SumoBots may contain an optional sensor upgrade).  SumoBots must measure no more than 7" by 7" in width.  There is no height limit.

Teams will compete randomly in one-on-one sumobot battles.  Each time slot will consist of 8 teams competing in a double-elimination tournament.  (Once a team loses twice they are eliminated)

Sample robot builds for both NXT and EV3 can be found here.

Sample software for the NXT can be found here.  Sample software for the EV3 can be found here.

The playing field is a rasied circle with the dimensions as shown below.

  • Diameter: 36 Inches
  • Border line: 1.25 Inches
  • Starting line width: 0.5 Inches
  • Starting line length: 4 Inches

The top surface is flat and smooth. The surface will be gloss-white in color. 
The starting lines are two parallel red lines centered on the field. 
The outer edge of the field, the border line, is a black circular ring.

SumoBots will begin the match behind their respective starting lines in any position, so long as all parts of the robot are behind the starting line. There will be a 5 second count down to starting both robots.  (The robot can be programmed, or started by hand)

A match will end when robot is completely out of the circle (off the raised mat), is tipped over and remains unable to move for a count of 5 seconds, or disabled and unable to move for a count of 5 seconds.  There is a 90 second time limit for each match.  In the event both robots are still running at the end of 90 seconds, the match is declared a draw.  (A drawn match can either be replayed, or considered a tie and both robots moved to face other robots in a match depending on the situation of the tournament and the judge(s) decision)

Fields may be constructed using painted sheet materials, or purchased online as a completed field with supports.


See below for a sample video of SumoBots in action!