Propulsion that does not involve driving wheels

[darkChozo]

Have you considered the safety factor of having a fan powerful enough to propel a ~150 pound robot faster than the wheels can? That's going to be quite a lot of wind. Considering that people are usually standing pretty close to the arena, I could easily imagine someone who is already off balance being pushed over and getting hurt by that. Same with light, unsecured equipment, or maybe tablecloths, barriers, etc. that can easily be blown up or away. And that's ignoring the damage that smaller things kicked up by the fan, or even worse, accidentally fed into the fan could do. It's not something I'd want to risk betting on at this point, lest it violate <S01>. I would wait until the Q&A clears things up.

Not to mention, I doubt that the crowd will appreciate being blown upon. Just a thought.