The annual robotic frenzy known as FIRST fills the Verizon Wireless Arena in Manchester this weekend as 44 teams from five states and two Canadian provinces compete to see whose robot does a better job shooting Frisbees and climbing scaffolding.

The Granite State Regional Competition includes teams from nine Greater Nashua high schools and a Souhegan Valley home-schooling group.

The event is free to watch. It’s open from 8:30 a.m.-5:30 p.m. Saturday .

Hundreds of people attend the event, as half of the arena’s floor is turned into a robotic version of the Indianapolis 500’s crew pits, where students and adult mentors work frantically on machines in preparation for competitions while the other half holds the competition floor.

Each year, FIRST invents a game in which robots compete in three-minute contests. This year’s game, called Ultimate Ascent, gives points for firing Frisbees through target windows and other points for climbing a scaffolding at game’s end.

Teams must cooperate as well as compete in order to win points and get trophies.

As has been the case for more than a decade, BAE Systems is the major sponsor of the event.

Teams from the regional will go to the national finals in St. Louis.

Teams are scheduled to compete from these local high schools: Bishop Guertin, Campbell, Hollis Brookline, Merrimack, Nashua North and South, Souhegan, Pelham and Windham, plus Milford-area home-schoolers.

For more information, visit www.baesystemsfirst.org/regional/index.htm.

– DAVID BROOKS