Is it ethical to alter cards and sell them without disclosure?

[G1911]

I am positive there is reasonable disagreement on edge cases.

Surely, if we dove deep enough, we could find a case of "robbery" where two reasonable men disagreed on if that particular case did or did not constitute robbery. Nonetheless, as reasonable men, surely we could reasonably say whether we are for or against "robbery" as it is generally understood by English speaking people to mean and has consistently been used.

While polls have 100 character limitations, even if I wrote a 300 page treatise we could surely find an example not covered and then use that as the angle to hem and haw.