The main focus of ROBOGAMES is the "Combat Arena", a large space (30x30?) surrounded by see-through plastic walls on all sides and covered with a roof structure (for lights, etc) and clear material as well. There were bleachers on three sides of the arena and they were full throughout the day with people watching the battles.
Middleweight (up to 60 lbs) and Heavyweight (up to 220 lbs) battles were held in the arena. These are very impressive. Most robots are squat and square (low center of gravity) and either try to flip their opponent (using an inclined front like the cow catcher on a train, sometimes with a extra hydraulic shove) or slam the opponent into the metal bars around the arena (using a blunt front) or simply thrash their opponent (saw blades were very popular). The top machine we saw was "Last Rites" which featured a blunt rotating 75-lb "blade" in the front. It absolutely destroyed "Vlad The Impaler II", an armored box which was a flipper. And I mean DESTROYED. Parts were flying everywhere, making us happy for the plastic walls.
It wasn't all about robot destruction. There were also art exhibits, robots wandering the floors, maze solving robots, robot soccer, robot "wrestling" (the small Lucha Libre robot was one of my favorites), and lego mindstorms competitions with younger kids.
All in all, a great day that was a heck of a lot of fun. I'm still perusing how one might design a combat robot that could actually survive a match and maybe even inflict some damage. And I'd highly recommend ROBOGAMES for the robot enthusiast in your family.