Ooh, plains might be a challenge. I imagine a cycle of different original basic lands:

W City
B Slum
U University
R Encampment
G Plains

Heh. In theory, basic lands and Legendary permanents are given the pass in the original rules. But, yeah, I did question whether passing on basics was necessary. Do you think using homonyms is an acceptable choice (In this case, using the name 'Planes'?) Or is that just opening these challenges to all kinds of abuse? (I got Plains. Plains rhymes with gains... so I added a suffix...)

I would generally say it's fine to skip them, but it's fine to answer them if they seem interesting. If I get a basic land AGAIN, I'm not sure I'll have another relevant card, but you never know.

I considered homonyms, I think that's not likely to be worth it, but I'm not worried if anyone else feels like trying that.