[ajlapp]

In all seriousness, even if you had a part that did not change at all there are endless ways you could change the design so it's not being reused. You could change the CAM file that generates the G-code to run the machine. You could make trivial dimension changes. You could issue a new drawing revision for some minor callout. You could change radii used on pockets/edges. The list goes on and on.

It's really a silly rule because FIRST is unwilling and probably more importantly unable to outline what qualifies as changing the design enough for them to be OK with it. It's also silly because anything you would re-use exactly as it was from the year before/offseason/etc is most likely a completely trivial part that would gain you no competitive advantage by designing up front.

The rule quite obviously exists to prevent you from designing an entire system of your robot before kickoff and then implementing it immediately, but you really can't design a system that can be used wholesale with no changes, because you have no idea what it needs to do.

Exactly.