An international robot tournament kicked off today, pitting 53,000 high school students around the world against each other.

In Quebec alone, 45 teams are competing in the FIRST Robotics Competition.

This year's theme? Medieval siege.

Teams will build robots that can infiltrate an opponent's defences in a high-tech arena. Mechanical and autonomous catapults must navigate around obstacles and hurl boulders into the other side's castle tower.

One of the competing schools is École secondaire Monseigneur-Richard in Verdun.

"It's pretty hard. It's our first year, so it's like a good challenge for us," said Smita Datta, one of the students.

They have just over six weeks to build their robots and program them for battle.

"We have to build the software, we have to build the programming, we have to basically assure that the communication is going to be there," said Gilles Beauchamp, the school's team mentor. "So it's a big, big challenge for us because we're building everything from scratch."

The Quebec finals will be in March. The winners will go on to compete at the international level in April, in St. Louis, Missouri.