Question about Booming Blade

[FlammySenpai]

So one of my party members is a College of Swords Bard. He has been using a combo lately that I had to take a closer look at. I previously allowed it because I was unfamiliar with the wording of Booming Blade. Basically what he would do is cast Booming Blade, and then for his melee attack he would use the Mobile Flourish ability, causing them to take the Booming Blade damage instantly. However I looked at the wording of Booming Blade, and there was a bit of an argument. I thought that since the wording states, "...and it can't willingly move or take 1d8 thunder damage", that they would not take the damage because they are not moving willingly. Wanted to get your guys' input, thanks so much!

[dejarnjc]

So one of my party members is a College of Swords Bard. He has been using a combo lately that I had to take a closer look at. I previously allowed it because I was unfamiliar with the wording of Booming Blade. Basically what he would do is cast Booming Blade, and then for his melee attack he would use the Mobile Flourish ability, causing them to take the Booming Blade damage instantly. However I looked at the wording of Booming Blade, and there was a bit of an argument. I thought that since the wording states, "...and it can't willingly move or take 1d8 thunder damage", that they would not take the damage because they are not moving willingly. Wanted to get your guys' input, thanks so much!

Your party member is incorrect and you are correct. The target has to use its own movement to trigger booming blade. Pushing effects do not trigger the cantrip.

[stack]

Mobile flourish is not willing movement, so it does not trigger booming blade.

Also, booming blade is a spell, so you are using the cast a spell action, not the attack action, so mobile flourish and booming blade can't be combined anyhow since the flourishes require attacking with an attack action.

[stoutstien]

Forced movement doesn't proc the secondary damage from booming blade. Spells that force a target to use their action like crown of madness/ fear are worded in way so it would work due to forcing the target to use their movement

[nickl_2000]

Your party member is incorrect and you are correct. The target has to use its own movement to trigger booming blade. Pushing effects do not trigger the cantrip.

It goes beyond this even. The target has to willingly move. So, a spell that forces the to use their movement is not willingly moving and wouldn't trigger BB.

[Man_Over_Game]

On this topic, there are a few things of note:


Forced movement: Unwilling movement, costs the mover no resources.
Opportunity Attacks: Requires the mover to move itself.
Booming Blade: Requires the movement to be willing.



In this case, something like Dissonant Whispers (Forces a target to flee) would trigger an Opportunity Attack but wouldn't trigger Booming Blade.

The opposite can also be true. Riding on a mount means that the rider is willing but not moving itself. The Horse would be the target of the Opportunity Attacks when the pair moves, but the Rider can still be subject to Booming Blade (because it's willingly being moved).

It's kinda odd, but that's what we got.

[dejarnjc]

It goes beyond this even. The target has to willingly move. So, a spell that forces the to use their movement is not willingly moving and wouldn't trigger BB.

True I forgot about that cause I ignore that one in my own game :P