Teams are challenged to design a Lego-based robot in order to complete missions on a game board provided by FIRST.  The goal of the game is for the robot to complete as many missions as possible under 2:30 min.  This board changes each season to incorporate a different theme.  Themes in the past have included Cargo Connect, Superpowered, and Masterpiece.   In addition to competing in the robot game, teams must also give a presentation describing the strategy and engineering design of their robot. 

Each season has an innovation challenge that each team must complete using the Engineering Design Process.  Teams are expected to design a solution to a problem, test their prototype, and then improve upon their original design.  Teams are required to demonstrate their prototype and describe how they accomplished each step of the Engineering Design Process to a judging panel as part of the competition.

Throughout the competition, teams are evaluated for their gracious professionalism, which is defined by FIRST as "a way of doing things that encourages high-quality work, emphasizes the value of others, and respects individuals and community."  In addition, teams must take into consideration the core values of discovery, impact, inclusion, innovation, teamwork, and fun in all their First Lego League endeavors.