Well, I was where you were 15 years go, said kid now is a robotics engineer.
First off, are they interested in the mechanical engineering and fabrication challenges? Or more interested in the behavior and controls challenges? Because you may chose a different path. At one point I regarded battle-bots as just an RC car with a bad attitude. But I have to admit that there are a lot of interesting mechanical design challenges to be solved. Melonee Wise did battle bots... and went on to co-found Fetch and is now CTO at Agility, so it can certainly lead to interesting things.
If more interested in behavior and controls challenges, then maybe you don't want to go the competition route at all, but want to make up a "challenge" and build a robot to target that. Like build a robot that can patrol your house, and take pictures of all the doors. Kind of a "security robot" (but not really all that useful) but I guarantee you will learn a lot attempting that. (In fact, that is probably too much for a first challenge.)
Lego Mindstorms has a lot going for it, but ultimately becomes limiting. Definitely not a bad place to start with a 10yo, but expect to move on.
Pololu and SparkFun have a lot of interesting modules, Pololu last I looked also had some basic platforms that make a good place to start. Also, depending on where you live there may be a good robotics club to join.
First off, are they interested in the mechanical engineering and fabrication challenges? Or more interested in the behavior and controls challenges? Because you may chose a different path. At one point I regarded battle-bots as just an RC car with a bad attitude. But I have to admit that there are a lot of interesting mechanical design challenges to be solved. Melonee Wise did battle bots... and went on to co-found Fetch and is now CTO at Agility, so it can certainly lead to interesting things.
If more interested in behavior and controls challenges, then maybe you don't want to go the competition route at all, but want to make up a "challenge" and build a robot to target that. Like build a robot that can patrol your house, and take pictures of all the doors. Kind of a "security robot" (but not really all that useful) but I guarantee you will learn a lot attempting that. (In fact, that is probably too much for a first challenge.)
Lego Mindstorms has a lot going for it, but ultimately becomes limiting. Definitely not a bad place to start with a 10yo, but expect to move on.
Pololu and SparkFun have a lot of interesting modules, Pololu last I looked also had some basic platforms that make a good place to start. Also, depending on where you live there may be a good robotics club to join.