Does the extra damage from Hex only applies if there is an attack roll?

@mikemearls @JeremyECrawford Can you confirm/deny that the extra damage from Hex only applies if there is an attack roll?

— J Larkin (@LordCyler) July 30, 2015

The extra damage in the hex spell requires an attack that hits, which is normally achieved with an attack roll. https://t.co/cE7zS4zznh

— Jeremy Crawford (@JeremyECrawford) August 4, 2015

@LordCylerCan you give an example when it wouldn’t be achieved with an attack roll? An attack that hits without an attack roll would be an oddity specified in a game effect—a thing you might never see in play.

— Jeremy Crawford (@JeremyECrawford) August 5, 2015

@JeremyECrawford @LordCyler does this mean that spells such as Arcane Missiles, Sacred Flame or Fireball don’t count as attacks?

— Sean (@Lord_Sicarious) August 5, 2015

A spell like fireball isn’t an attack; it doesn’t include an attack roll, and it’s not called an attack in its text. https://t.co/SAH1DB4Eou

— Jeremy Crawford (@JeremyECrawford) August 5, 2015