Each group needs:

• LEGO MINDSTORMS EV3 robot, such as the EV3 Core Set (5003400) at https://education.lego.com/en-us/products/lego-mindstorms-education-ev3-core-set/5003400#lego-mindstorms-education-ev3 (includes programmable EV3 intelligent brick; 2 interactive servo motors; color, ultrasonic and 2 touch sensors; and many other components and instructions)
• LEGO MINDSTORMS Education EV3 Software 1.2.1, free online, at https://www.lego.com/en-us/mindstorms/downloads/download-software. You have to register a LEGO account first. 
• computer, loaded with EV3 1.2.1 software
• Sumobot Challenge Pre-Quiz, one per student
• Sumobot Challenge Post-Quiz, one per student
• paper and pencils, for brainstorming and drawing designs

Alternative: LEGO MINDSTORMS NXT Set:

Note: This activity can also be conducted with the older (and no longer sold) LEGO MINDSTORMS NXT set instead of EV3; see below for those supplies:

• LEGO MINDSTORMS NXT robot, such as the NXT Base Set (includes programmable NXT intelligent brick; 3 interactive servo motors; sound, light, ultrasonic and 2 touch sensors; and many other components and instructions)
• LEGO MINDSTORMS Education NXT Software 2.1 
• computer, loaded with NXT 2.1 software

To share with the entire class:

• Sumobot Challenge Presentation (EV3 version), Microsoft^® PowerPoint^® file or Sumobot Challenge Presentation (NXT version)
• computer and projector, to show the presentation
• measuring tape or ruler, to measure the challenge ring
• black tape, to mark the challenge ring on the floor
• 2 little stickers, taped signs or Post-it^® Notes, to signify the robot starting points