You're assuming another rule here, which not only isn't written but is even explicitly excluded in the very beginning of this experiment.

Correct. But you (and the experimenter) are assuming that rules exist in a vacuum, which in practice it isn't

No the experimenter doesn't assume that, they say: "please answer the question of whether the rule is violated (not whether the violation should be allowed)."

The intent of the experiment is to get your view on whether X is a vehicle or not, and whether Y counts as a place "in the park" or not.

Yes, but that is an actual situation in real world.

Both "No vehicles" and "in the park" already require you to have external knowledge. What is a vehicle? What constitutes park grounds?

That is part of the point of the exercise. You can expand on this rule, but however far you go there will continue to be things that are not clear.

The game didn't say the park is contained in another land. It's a "hypothetical park". It could even exist in a virtual reality that doesn't have any other rules for all we know.

Yeah, the game is very specific about other rules not applying. It's about "what exactly is and is not in" (in the airliner and space station question) and about "what exactly is and is not vehicle" (all others)

> supersede some local rule

aka, there's some other rule that isn't listed then?

Which isn't what is being discussed here.

Yes, you're assuming that this is a jurisdiction where police or ambulances have authority over local rules

> It doesn't matter, the rules on police and emergency vehicles usually supersede some local rule about a park.

Nobody said it was a local rule. It could be a federal rule about a federal park. And it could be there for a more important reason than keeping ATVs off the hiking trails.