Following the Rules as Written, no, the spells do not work together. However, Crawford has said removing this interaction is not what they intended when reworking Booming Blade and Green-Flame Blade.
Can green flame blade be twinned?
Green flame blade cannot be twinned as it can affect two targets. Since green flame blade can’t be twinned I’ll cover the more general case of how this would work. Twinned Spell causes the spell to target two creatures instead of one.
Does green flame blade work with thirsting blade?
Nope. Thirsting Blade requires taking the Attack action.
What classes get green flame blade?
As stated above, any class can take Green Flame Blade and see a benefit, but the classes that have access to the spell without burning a feat are the Sorcerer, Warlock, and Wizard. The Eldritch Knight Fighter and Arcane Trickster also have the spell available to them based on the lists they use.
Can you cast green flame blade with shadow blade?
Since this spell creates “a sword of solidified gloom” without reference to the weapons table, the shadow blade has no value. As such, it does not satisfy the material component of the blade cantrips. For confirmation, see Crawford’s tweet above. Green-Flame Blade no longer works with Shadow Blade.
What does green-flame blade do?
Green-flame blade adds your spellcasting ability modifier to the second-target damage (so most likely 1d8+4 at 5th level) and booming blade does an extra 1d8 (scaling normally; 2d8 to 5th level) if the target moves within one round.
How does quickening the Green Flame Blade work?
Quickening the Green Flame Blade cantrip lets you cast it as a bonus action using the Cast a Spell (bonus) action. As part of this, you make one melee weapon attack. No part of this restricts what weapon you may use, other than a range of 5 ft. You then use your action to take the Cast a Spell action, again casting GFB.
What’s the difference between Shadow Blade and Green Flame Blade?
To go through the logic: Green flame blade requires you to attack with a weapon you are holding and shadow blade explicitly creates a weapon ( as opposed to say flame blade ).
How long does it take to cast Green Flame Blade?
The spell Green-Flame Blade has a casting time of one action and is also a cantrip. Therefore it seems like a sorcerer should be able to cast it as their action and (by using Quickening) their bonus action.
Do you have to cast Shadow Blade every turn?
You have to cast it as an action, it’s a bonus action to move the hand, and it’s a separate bonus action to get advantage using it. Shadow blade is simpler and doesn’t use your bonus action every turn. Pair it with green flame blade or booming blade to add some fire or thunder damage to shadow blade’s psychic damage on top of your Sneak Attack.
