It sounds simple enough. Just move a small beanbag from here to there, using a homemade robot.

That’s the challenge for 28 teams of middle and high school students in Saturday’s Southern Maine VEX Robotics Tournament.

The competition, to be held at Cape Elizabeth Middle School at 14 Scott Dyer Road, will run from 9 a.m. to 4 p.m. and is free and open to the public.

All of the teams will have the same test: Get their robot to pick up small square beanbags and then score points by placing them in three spots: on the floor, in an 18-inch-high trough or on a 30-inch-high triangular shelf.

The tougher the challenge, the more points.

“Some kids will decide to go for the most points and spend their time on just the toughest one,” said Evan Thayer, robotics instructor at Cape Elizabeth High School, which has several teams in the competition.

The teams make their robots out of the same materials, all supplied by VEX Robotics. To qualify, a robot must fit inside an 18-inch cube. Outside the cube, the robot can unfold to any shape or height.

“It’s so great to see what the kids can do,” said Kathy Barber, an organizer who has helped with the robotics competitions for four years.

In addition to robotics and engineering, the students learn about teamwork and strategy. Different teams are paired up for some parts of the competition.

The game is played in a 12-foot-by-12-foot area. Pairs of teams compete in a 15-second autonomous mode, in which robots run off software programs written by the students, and in a one-minute-and-45-second event in which the students hand-drive the robots against an opposing team.

The tournament is sponsored by Fairchild Semiconductor and co-hosted by the University of Maine, Orono College of Engineering and Black Bear Robotics.

VEX Robotics has more than 4,800 teams in 20 countries that play in more than 300 tournaments worldwide.

The winner of the Excellence Award on Saturday will go on to the world championship, to be held in Anaheim, Calif., in April.

All of the quarterfinalists will qualify for any of three 2013 New England regionals, to be held in March in New Hampshire, Massachusetts and Connecticut.

Staff Writer Noel K. Gallagher can be contacted at 791-6387 or at:

[email protected]