Correct me if I'm wrong

[Tristan Lall]

The real problem is that FIRST has been equating normal force or frictional force with traction. They're not the same, but are obviously related: traction is a motive force derived from friction between surfaces and normal forces on the scale of interlocking surface features, while the overall normal force and frictional force are related to any downward components of force (e.g. from weight, downward thrust, momentum over time, etc.).

This has led to Q&A posts that do not frame the response in terms of the stated objectives and context of <R06>—to restrict devices other than rover wheels that would increase traction by interacting with the arena.

Only the craziest interpretation of <R06> leads to the conclusion that downward-thrusting fans that interact with the air are traction devices. It's crazy, because if you're going that route, the rules don't give any leeway to ignore the traction-increasing effects of weight and momentum. As far as the rover wheels are concerned, all downward force increases traction, no matter whether it is a result of gravity, or a fan pushing air upward.

And of course, because this information was released in Q&As, a team might quite reasonably object on the grounds that it is a non-binding statement, rather than an enforceable rule.

Note, also, that the statements about vacuum cups and similar devices stem from <G29> and <G30> issues (i.e. field damage). Even then, there is no prohibition; just a stern warning and the threat of being restricted from using the robot.