There are actual autonomous robot competitions. They don't tend to be as adrenaline-filled as the battlebots, they really don't make good TV, but they're fun. S

There are actual autonomous robot competitions. They don't tend to be as adrenaline-filled as the battlebots, they really don't make good TV, but they're fun. Some have quite low barriers to entry. If you want to dip your toe in you can put together a mini-sumo or maze-running entrant without a ton of time/materials investment.