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Watch These Robot Alliances Destroy Each Other’s Forts

The FIRST Robotics Championship is for amateurs, but it’s pretty hard to tell.

Saturday marked the conclusion of the 2016 FIRST Robotics Competition, which saw over 20,000 high school students from around the world descend on St. Louis, Missouri for the annual event. Now in its 25th year, the 2016 FIRST competition was held over four days during which 900 teams pitted their robots against one another in various games.

The teams had spent the last six months working on the robots which had to work their way up through regional and district competitions before making it to the championships in St. Louis. Here they put on an impressive show for the 40,000 spectators in attendance, which included some big names like and NASA Administrator Charles Bolden. The robots, which could weigh up to 120 pounds, had to be designed so they could complete a variety of tasks, such as throwing balls and discs through goals, hanging on bars, and balancing on balance beams.

The ultimate robotics test occurred in the championship round, known as the FIRST Stronghold, which involves two alliances composed of three robots each. At each end of a pitch are two towers, representing each alliance's stronghold. The alliances must breach their opponent's stronghold by throwing boulders to goals on the tower to weaken it.

This year's winning alliance included teams from California, Illinois, Ohio and Virginia, which were mentored by employees at NASA-JPL, Boeing, Raytheon and other engineering giants. All the teams at the FIRST competition were competing for a number of different prizes, which ranged from lifetime admittance to the championship regardless of robot performance to a massive Möbius-strip trophy.