"It's not about arguing. It is about debating and in the process you don't cheat when doing it."
And to keep it in context i'd suggest formal rules as you suggest don't normally apply at family gatherings, in pubs or other places where the arguments she was addressing normally occur.
It was Plato who said, “He, O men, is the wisest, who like Socrates, knows that his wisdom is in truth worth nothing”