Booming Blade on prone opponent: can they get up without going boom?

[Unoriginal]

Booming Blade's effect trigger when the affected enemy willingly moves. Is there anything saying getting up from being knocked prone count as movement, for this?

On one hand, you don't move from the space you're in. But on the other, it costs movement and you're definitively moving more within your space by doing this than if you're, say, turning on yourself to fight someone who was in your back.

Myself as a DM I would rule that it does count at moving, but what's your opinion?

[Ganymede]

I'd let you stand up from prone without bringing the boom, but it is moot as I don't allow SCAG anyways.

[Laserlight]

I'm fairly sure Crawford ruled that getting up from prone does not count as "moving".

I don't recall any attempt to explain why that could make sense.

[ProsecutorGodot]

By RAW standing up from prone isn't the same as moving, so a creature wouldn't trigger the booming blade proc. The only movement option you have while prone is crawling or teleportation, standing up isn't recognized as moving in this scenario.


I'm fairly sure Crawford ruled that getting up from prone does not count as "moving".

I don't recall any attempt to explain why that could make sense.
If we do choose to count it as moving, we'd open up a pretty big can of cheese by putting a prone target in difficult terrain. They'd have to expend their entire movement just to stand.

[BarneyBent]

I'm fairly sure Crawford ruled that getting up from prone does not count as "moving".

I don't recall any attempt to explain why that could make sense.

I think it makes sense. You’re “surrounded” by the BB energy. I interpret that as you trigger it by moving through it. Therefore, if you stay in the same spot, you’re probably fine. With that interpretation, you could rule either way (you stand up, your head hits the top of the energy sphere thingy and it gets triggered) which leaves it in the DMs hands, as it should be.

[MaxWilson]

Booming Blade's effect trigger when the affected enemy willingly moves. Is there anything saying getting up from being knocked prone count as movement, for this?

On one hand, you don't move from the space you're in. But on the other, it costs movement and you're definitively moving more within your space by doing this than if you're, say, turning on yourself to fight someone who was in your back.

Myself as a DM I would rule that it does count at moving, but what's your opinion?

I could see it either way, depending on whether you think the "booming energy" is more like shackles of air which explode when stretched too tightly, or like a cocoon which shatters when deformed.

Up until now I've always just shrugged and gone with Crawford's interpretation (which means the former: shackles of air) because I don't really care that much either way. It's sort of like how I tolerate the stupid name "Booming Blade" instead of exclusively calling it False Fetters: you gotta pick your battles.

But my first preference would be for it to act like a cocoon, which means standing up = boom.


If we do choose to count it as moving, we'd open up a pretty big can of cheese by putting a prone target in difficult terrain. They'd have to expend their entire movement just to stand.

That's not how difficult terrain works. It's not a multiplier on all movement costs. E.g. crawling in difficult terrain doesn't cost 4' of speed per foot moved. Difficult terrain just makes it cost 2' to move one foot, so standing up isn't more expensive in difficult terrain.

[Tanarii]

By RAW standing up from prone isn't the same as moving, so a creature wouldn't trigger the booming blade proc. The only movement option you have while prone is crawling or teleportation, standing up isn't recognized as moving in this scenario.
Does Booming Blade trigger when you teleport? I've never thought about it, since I don't use SCAG content IMC.

[nickl_2000]

Does Booming Blade trigger when you teleport? I've never thought about it, since I don't use SCAG content IMC.

Why would it? You aren't using movement to teleport.

The question is, if you teleport and then move afterwards does it proc? My call as a DM would be yes, but I can see the logic behind either answer

[stoutstien]

BB should have just proc if you attack to clean up all this mess.
So I attack an enemy and if they try to attack action n the next turn the BB goes off

[Laserlight]

By RAW standing up from prone isn't the same as moving, so a creature wouldn't trigger the booming blade proc. The only movement option you have while prone is crawling or teleportation, standing up isn't recognized as moving in this scenario.

If we do choose to count it as moving, we'd open up a pretty big can of cheese by putting a prone target in difficult terrain. They'd have to expend their entire movement just to stand.

Found the tweet: Standing up costs movement but moves you nowhere. (https://twitter.com/JeremyECrawford/status/663030224154562561)

However, I don't see that "standing up from prone isn't the same as moving". PHB 190-191: Standing up takes more effort; doing so costs an amount of movement equal to half your speed. For example, if your speed is 30 feet, you must spend 15 feet of movement to stand up. You can ’t stand up if you don’t have enough movement left or if your speed is 0. It's not "your speed is reduced by half" or anything of that sort; you're using movement.

The next paragraph says To move while prone, you must crawl or use magic such as teleportation, but I read that as "moving while remaining prone".

As far as "prone in difficult terrain" being a problem, so what? It's already explicit in the PHB that if you don't have enough movement to stand, you don't stand. And conceptually, if you get knocked down on ice or in mud, I can see having to use your action for Dash to get enough move to stand.

[Laserlight]

BB should have just proc if you attack to clean up all this mess. So I attack an enemy and if they try to attack action n the next turn the BB goes off

Then you get into the "magic missile isn't an attack" line of discussion.

[Malifice]

It only triggers if you willingly leave your space.

Standing up or forced movement doesnt count.

[MaxWilson]

Found the tweet: Standing up costs movement but moves you nowhere. (https://twitter.com/JeremyECrawford/status/663030224154562561)

That's obviously unphysical. It moves you vertically.

[HappyDaze]

It only triggers if you willingly leave your space.

Standing up or forced movement doesnt count.

So if someone shoves you out of that space, does the effect follow you and go off when you move out of your 'new' space?

[Mjolnirbear]

If we apply some surface logic, it might help with deciding how to rule it.

You don't actually occupy a 5' space. You're bouncing and weaving, ducking and dodging, and this combat movement means you 'control' an area. You still get a Dex bonus to AC and can roll Dex saves normally. Your movement is not restricted.

Since constantly moving within 5' does not trigger the boom, then it is not a strict definition of movement; it must be something else. That leaves a few alternatives:
1) using at least 5' of movement (going by movement abilities). Using this rule, getting up from prone and difficult terrain probably count, but teleport does not unless you move after (the effect is tied to you)
2) moving at least 5' (going by distance moved). Prone doesn't count, difficult does, teleport doesn't unless you move after (the effect is tied to you)
3) leaving the space you're in (going by location). Prone doesn't count, difficult and teleport both do.

Given you are 'surrounded by Thunder energy' I'd personally guess 1 or 2. I'm prone to #1, but when 8 started writing this, I was leaning towards 3 *laugh*

Edit: since, too, we don't have 'move actions' nor 'move-equivalent actions' in this edition, and minor object interactions never involve movement, I'm also more inclined to say that standing up counts as movement because it costs movement.

[Malifice]

So if someone shoves you out of that space, does the effect follow you and go off when you move out of your 'new' space?

Yes.

If you willingly move out of whatever space you're in before the end of your next turn, you take the extra damage.

[Unoriginal]

Alright, I've seen good arguments for why standing up wouldn't trigger it.


Now, do we all agree that if you jump straight up, it does trigger it, even if you land back in your square?



So if someone shoves you out of that space, does the effect follow you and go off when you move out of your 'new' space?

This is correct.

[Kadesh]

'if your heart pumps blood does that count as willingly moving for the booming blade'
Okay, neat troll thread.

[Malifice]

Now, do we all agree that if you jump straight up, it does trigger it, even if you land back in your square?

If we consider the space you occupy to be three dimensional (which it is) then yes; willingly moving vertically out of your space (jumping, levitating, flying etc) also triggers the damage.

Its a simple question. If the creature nailed by the spelll willingly moves out of his space before the end of his turn, he takes the damage.

If the movement is not willing, or if he moves but stays in his space, he doesnt take the damage.

[Laserlight]

The difficulty is that BB says "moves", not "moves from its space", which is probably what it should say.

[MeeposFire]

To me it always seemed that this spell was ported over from 4e with minimal changes but the people in charge of this forgot that the game does not use the same language anymore and something that was fairly simple to implement in 4e with this language is less so in 5e.

[JackPhoenix]

Booming Blade is a bad spell, because its effect only make sense in the game mechanics, not in fiction. The target is surrounded by "booming energy", whatever is that supposed to mean, but it only goes off if he moves around. Being pushed or dragged around? No boom. Teleportation? No boom, but the energy stays with him. Reaching out of your space to touch the enemy (say, bugbear with 10' reach)? No boom. Moving around inside your 5' cube, as is normal in combat? No boom. Actually running around because you've been scared by Dissonant Whispers? Still no boom. Awfully specific.

Make it air path alteration illusion or enchantment school, change the damage to psychic (thunder and psychic damage has about the same value), and all those inconsistencies will disappear, because there's no physical component anymore, it's all in the victim's mind, like Phantasmal Force. And change the name to something that sound less like something out of 4e.

edit: heh. Ninja'd on the 4e comment.

[Mjolnirbear]

Booming Blade is a bad spell, because its effect only make sense in the game mechanics, not in fiction. The target is surrounded by "booming energy", whatever is that supposed to mean, but it only goes off if he moves around. Being pushed or dragged around? No boom. Teleportation? No boom, but the energy stays with him. Reaching out of your space to touch the enemy (say, bugbear with 10' reach)? No boom. Moving around inside your 5' cube, as is normal in combat? No boom. Actually running around because you've been scared by Dissonant Whispers? Still no boom. Awfully specific.


A pedantic Jessica Rabbit would say: "I'm not bad, I'm just drawn that way". The spell is a very good spell. It's just written confusingly from a narrative perspective. The DM has to make assumptions about its intended consequence, and the move mechanic assumption is not hard to come by, given circumstances. It's the specifics, like jumping and prone and teleport, that need expanding upon and DM adjudication.

It's hardly the only 5e spell with these issues. Any spell that refers to something that has both a game term and a 'Common language' usage suffers this problem.

See: fire spells that do not ignite things, lightning spells that defy current and grounding rules, poison spells that don't poison you, illusions that have real effects or do non-psychic damage, and frost spells that don't preserve butchered meat.

[MeeposFire]

Well actually it is from 4e. It is one of the many, MANY things they ported from it but unlike most of it they did not change as much from this particular ability as they did other things. The original booming blade spell was for the Sword Mage class an arcane defender. It was a popular at will for the class. It was great and fairly popular at the time but it seems to me that they did not give it the same level of hiding the mechanics in narrative as they did many other things from 4e. One big difference between 4e and 5e is that 4e is much more blatant in being a game and expects you to imagine how to deal with the mechanics when describing the world while 5e takes some more time to somewhat hide the mechanics to an extent.

[Malifice]

Booming Blade is a bad spell, because its effect only make sense in the game mechanics, not in fiction. The target is surrounded by "booming energy", whatever is that supposed to mean, but it only goes off if he moves around. Being pushed or dragged around? No boom. Teleportation? No boom, but the energy stays with him. Reaching out of your space to touch the enemy (say, bugbear with 10' reach)? No boom. Moving around inside your 5' cube, as is normal in combat? No boom. Actually running around because you've been scared by Dissonant Whispers? Still no boom. Awfully specific.

Make it air path alteration illusion or enchantment school, change the damage to psychic (thunder and psychic damage has about the same value), and all those inconsistencies will disappear, because there's no physical component anymore, it's all in the victim's mind, like Phantasmal Force. And change the name to something that sound less like something out of 4e.

edit: heh. Ninja'd on the 4e comment.

'Wreathed in booming energy because: Magic.'

Not logic. Not physics.

Magic.

See the flaw in your reasoning?

[Ganymede]

'Wreathed in booming energy because: Magic.'

Not logic. Not physics.

Magic.

See the flaw in your reasoning?

When people make this point, it isn't because they are insisting things like Booming Blade be logical or align with the laws of physics, just that they have fidelity in our suspension of disbelief.

[ProsecutorGodot]

That's not how difficult terrain works. It's not a multiplier on all movement costs. E.g. crawling in difficult terrain doesn't cost 4' of speed per foot moved. Difficult terrain just makes it cost 2' to move one foot, so standing up isn't more expensive in difficult terrain.
Yes, that's the problem if we decide to treat standing up as movement that would trigger booming blade. If you treat standing up as movement, every foot you move (half of your movement) to stand up is doubled costs 1 extra (your entire movement, and effectively the same as doubling it) in difficult terrain. Which is why it doesn't make sense from a mechanical standpoint to treat it as movement for booming blade, because then you would have to follow suit with this ridiculous ruling on standing up from prone in difficult terrain.

With the way standing from prone is worded, you're not actually moving even though you're expending movement. If the argument in favor of having it trigger booming blade is that it counts as movement, we're forced to have it count as movement for the rest of the mechanics that ask for it.


Does Booming Blade trigger when you teleport? I've never thought about it, since I don't use SCAG content IMC.
I'd argue that since even though teleportation is listed as a movement option, it's given exception to almost every consequence of moving listed in the PHB, that it wouldn't trigger booming blade. This is entirely in the realm of DM ruling though, I don't think there's any easy answer for this in the books.

[Malifice]

When people make this point, it isn't because they are insisting things like Booming Blade be logical or align with the laws of physics, just that they have fidelity in our suspension of disbelief.

I have no need to try and frame the 'booming energy from a magical spell' as something logical or rational or conforming to physics.

It's magic. By definition, it exists outside of logic and falsifiabiliy.

Same deal when people try and argue the genetic composition of half elves and their offspring, or half dragons an the like. When you're talking about 'magical elves from an alternate dimensions/ 5 tonne flying fire breathing lizards breeding with humans', genetics doesnt come into it.

[Ganymede]

I have no need to try and frame the 'booming energy from a magical spell' as something logical or rational or conforming to physics.

It's magic. By definition, it exists outside of logic and falsifiabiliy.

Same deal when people try and argue the genetic composition of half elves and their offspring, or half dragons an the like. When you're talking about 'magical elves from an alternate dimensions/ 5 tonne flying fire breathing lizards breeding with humans', genetics doesnt come into it.


Why did you choose to repeat yourself when I previously pointed out that "logic and falsifiability" are NOT what was being talked about?

You're the only one talking about logic and physics. That's it. Just you. And you bring it up again. Why?

[Malifice]

You're the only one talking about logic and physics. That's it. Just you.

The post to which I was responding:


Booming Blade is a bad spell, because its effect only make sense in the game mechanics, not in fiction. The target is surrounded by "booming energy", whatever is that supposed to mean, but it only goes off if he moves around. Being pushed or dragged around? No boom. Teleportation? No boom, but the energy stays with him. Reaching out of your space to touch the enemy (say, bugbear with 10' reach)? No boom. Moving around inside your 5' cube, as is normal in combat? No boom. Actually running around because you've been scared by Dissonant Whispers? Still no boom. Awfully specific.

I call that trying to rationise the spell using logic.

Its magic. Why bother trying to rationalise it?

[Ganymede]

The post to which I was responding:



I call that trying to rationise the spell using logic.

Its magic. Why bother trying to rationalise it?

That's your third time doing it.

lol, bye.

[Malifice]

That's your third time doing it.

lol, bye.

Nah; that's the third time you're wrong.

See ya.

[JakOfAllTirades]

Why did you choose to repeat yourself when I previously pointed out that "logic and falsifiability" are NOT what was being talked about?

You're the only one talking about logic and physics. That's it. Just you. And you bring it up again. Why?



Actually, Malifice is the practically the only one who isn't arguing those.

[Ganymede]

Actually, Malifice is the practically the only one who isn't arguing those.

I was referring to the post Malifice responded to. I certainly can't vouch for anyone else.

[stoutstien]

The post to which I was responding:



I call that trying to rationise the spell using logic.

Its magic. Why bother trying to rationalise it?
Because without a baseline of understanding every spell would be completely up to arbitrary rulings.
Booming blade extra damage is based around movement which is a resource of sort that you can use on your turn.
Hence the question, standing cost movement but is it actually movement.
Sometimes you have to make a ruling purely based on balance. BB is already a strong option so adding that it proc if the target is trying to stand makes it even more powerful but that just my opinion.

[ProsecutorGodot]

However, I don't see that "standing up from prone isn't the same as moving". PHB 190-191: Standing up takes more effort; doing so costs an amount of movement equal to half your speed. For example, if your speed is 30 feet, you must spend 15 feet of movement to stand up. You can ’t stand up if you don’t have enough movement left or if your speed is 0. It's not "your speed is reduced by half" or anything of that sort; you're using movement.

The next paragraph says To move while prone, you must crawl or use magic such as teleportation, but I read that as "moving while remaining prone".

As far as "prone in difficult terrain" being a problem, so what? It's already explicit in the PHB that if you don't have enough movement to stand, you don't stand. And conceptually, if you get knocked down on ice or in mud, I can see having to use your action for Dash to get enough move to stand.

"Moving" in the PHB is determined by the distance travelled

However you're moving, you deduct the distance of each part of your move from your speed until it is used up or until you are done moving.
Standing up from prone doesn't involve travelling any distance, it's not moving. Your "movement" is a resource determined by your speed stat, expending from it doesn't always mean that you've moved. Standing up from prone is spending half of your speed in movement to end the prone condition, you haven't moved any distance.

On the bolded part, I read that as "If I'm not crawling or teleporting while prone, I haven't moved" which makes a lot more sense in the context of "Your only movement option while prone is to crawl or teleport"

The mechanical ramifications of saying that standing up from prone is a form of movement allows you to knock a giant or larger sized creature prone and place an ally (even a tiny familiar would work to immobilize medium or larger sized creatures in this way) atop them would render that creature unable to stand without using the dash action, since they would suffer from difficult terrain "moving" through your ally space. Is it stupid? Absolutely, but it works if you treat standing up from prone as a form of movement.

This is also a fantastic way to prank the party barbarian during his morning workout, simply place a kitten on his back while he does his push ups and watch him struggle against the weight of the world.

Also how then do we rationalize the ability to freely drop to prone costing zero movement and thus not triggering the effects of booming blade? What makes dropping prone different enough to be safe against the "booming energy"?

[Aimeryan]

This is one of those 'plain English' vs game terminology issues that 5e seems to love. The problem is that the developers wanted an edition that seemed easy to parse, but because of ambiguity and interpretation it is anything but. Personally, I would have preferred precise language using defined terms (keywords) - it might not look as easy to read at first glance but it definitely helps clear up such issues.

Anyhow, yeah, depending on how you interpret 'willing move' you can have by RAW anything from not choosing to act as though you were paralysed to travelled at least x distance - and even then you have the question of teleportation. Pick something your players all agree on and then rule consistently from that.

[BarneyBent]

This is one of those 'plain English' vs game terminology issues that 5e seems to love. The problem is that the developers wanted an edition that seemed easy to parse, but because of ambiguity and interpretation it is anything but. Personally, I would have preferred precise language using defined terms (keywords) - it might not look as easy to read at first glance but it definitely helps clear up such issues.

Anyhow, yeah, depending on how you interpret 'willing move' you can have by RAW anything from not choosing to act as though you were paralysed to travelled at least x distance - and even then you have the question of teleportation. Pick something your players all agree on and then rule consistently from that.

Eh, I agree with the second para, but I feel like the 5e criticism is not quite right. 5e tries to be less prescriptive. Obviously there’s rules and mechanics, but it’s always up to the DM. A DM could rule either way on this spell and it wouldn’t break the spirit of the spell nor buff/nerf it too heavily, nor fundamentally change the way it interacts with other mechanics. To me, that’s working as intended. JC might have a preferred interpretation in mind but he’d be the first to say “whatever your DM says”.

[Aimeryan]

Eh, I agree with the second para, but I feel like the 5e criticism is not quite right. 5e tries to be less prescriptive. Obviously there’s rules and mechanics, but it’s always up to the DM. A DM could rule either way on this spell and it wouldn’t break the spirit of the spell nor buff/nerf it too heavily, nor fundamentally change the way it interacts with other mechanics. To me, that’s working as intended. JC might have a preferred interpretation in mind but he’d be the first to say “whatever your DM says”.

That is not really edition specific, though - indeed, there is even a name for this: houserules.

Simplifying things is always a valiant pursuit, however, when it comes at the cost of clarity I would rather have the clarity. When it comes to something like "when you willingly move" that should have set alarms going for anyone and everyone in quality control as being incredibly unspecific. If taken literally it should go off pretty much instantly for most targets because it is difficult to remain completely motionless, even ignoring external forces.