@JeremyECrawford with the green flame blade spell . Do you use your melee attack mod or spell attack mod ?

— Amphieuss (@Amphieuss) December 11, 2015

Spellcasting modifier is used for a spell attack, as in ray of frost. No spell attack in green-flame blade. #DnD https://t.co/6SflFv3Akf

— Jeremy Crawford (@JeremyECrawford) December 11, 2015

@JeremyECrawford so with Green flame and booming blade you use your melee attack mod even though it's a spell.?

— Amphieuss (@Amphieuss) December 11, 2015

Take a look at ray of frost. See "spell attack"? Green-flame blade and booming blade don't say that. #DnD https://t.co/ccC4PR8ANE

— Jeremy Crawford (@JeremyECrawford) December 11, 2015

@clancey70 @JeremyECrawfordSo Green-flame blade does not count as a magic attack as far as hitting subjects with mundane attack resistance/immunity? The extra damage from Green-Flame Blade is magical. The weapon damage depends on the weapon, not the cantrip.

— Nate (@Daeva001) January 15, 2016

This rules answer is so on-target that I'm retweeting it! #DnD https://t.co/94XrEPZiiN

— Jeremy Crawford (@JeremyECrawford) January 15, 2016