The Rules of Rap

Ghostwriting?

Biting???

Cap???

Originality??

Beef????

Lyricism?????????

Does anyone know the actual rules to this sh*t????

Now that battle rap/beef has become the mainstream topic from the Drake beefs. Are any of these guys even following the rules? Some people say all the actual "best" rappers are unknown. But someone like Drake or Lil Wayne can play lyrical tricks while being sonically pleasing to people who can't even speak the language. How does that factor in vs the technical skills of battle rappers, for example?

How could that possibly be the case? Why can't they write in a tasteful flow or create their own after x years?

I doubt we can agree on lyricism standards, but maybe just the general rules on what's highly regarded and what's not?

All opinions welcome. Anybody?????