So, I just looked this up after listening to Taako cast this spell on a kraken during the latest live episode of The Adventure Zone.  Apparently Justin was right; as far as I can tell, you can absolutely force a kraken to tap its tentacles and caper until its next turn, at least O_O

If only Vox Machina had known, Keyleth's Aramente would have gone a lot differently...

Yeah, but Sam was playing Taryon at the time.

Incredible spell. Pumped to use it some day.

Quote from Spameroo >>

So, I just looked this up after listening to Taako cast this spell on a kraken during the latest live episode of The Adventure Zone.  Apparently Justin was right; as far as I can tell, you can absolutely force a kraken to tap its tentacles and caper until its next turn, at least O_O

If only Vox Machina had known, Keyleth's Aramente would have gone a lot differently...

 I was shocked to learn after that episode that the kraken doesn't have legendary resistances. I should have given Griffin the benefit of the doubt!

WHY IS THIS SPELL SO GOOD?!!?!?!?! WAY TO OP - YOU STOP THE ENEMY FROM ATTACKING!!!!!!

Quote from Provoke64K >>

WHY IS THIS SPELL SO GOOD?!!?!?!?! WAY TO OP - YOU STOP THE ENEMY FROM ATTACKING!!!!!!

 so does hold monster.  it just gives you one free round.

Quote from Provoke64K >>

WHY IS THIS SPELL SO GOOD?!!?!?!?! WAY TO OP - YOU STOP THE ENEMY FROM ATTACKING!!!!!!

It can still attack just at disadvantage. Otherwise it can use it's action to try and save on its turn. Also a creature with a Legendary Resistance can save out of it on his turn, basically only losing one turn. It's not that OP. Not to mention the dancing doesn't prevent it from using spells. 

My group is discussing this right now.  

The wording says that "As an action, a dancing creature makes a Wisdom saving throw to regain control of itself. "  

It doesn't say that it MAY use its action to make the saving throw. It says that it uses its action, which makes it sound like it forces them to use their action.  I feel like most everywhere else, it specifies "may/can" or "must", but doesn't here.

Looking at the description of the movement penalty it says you MUST use all your movement to dance. However, it doesn't say you must attempt a save. Telling you that as an action you make a wisdom save is telling the players it will take a full action to attempt to save. Spells where you must make a save will use the word must. That is how I would rule it.

Crawford has weighed in saying that no matter what at the start of your turn you lose all your movement even if you use an action to save. 

Right, it is just a weird inconsistency in wording from other instances and came up due in a session, so we were discussing it afterwards.

I feel like a sixth level spell that only immobilizes and imposes advantage/disadvantages, aside from one guaranteed round of movement loss, is way underpowered. Hold Monster is way more powerful, as it paralyes the target, facilitating auto-crits and loses ALL actions for each turn, not just movement.

Ok, seriously, why is this a 6th level spell? Gameplay wise, it has no effect that Hideous Laughter, a first level spell, other than its a little harder to break the effect, but seriously, that not worth a 6th level spell as long as spells like Hideous Laughter or Hold person exists...

As someone named otto, I want this

For those that feel this spell is underpowered, do note that this spell is guaranteed to take effect (barring charm immunity) for at least 1 turn because the save is made on their turn using up an action. Sure, they might make the save, but a 6th level slot to guarantee that a creature skips a turn + advantage on attacks is a pretty good boss killer. 

Funny, this spell never actually charms the target, it just doesn't affect creatures immune to charm. So Fey Ancestry wouldn't give an elf advantage to regain control. Interesting!

isnt this terrible?? like isnt hideous laughter just better? why is this level 6? people in the comments seem to think its great but it looks terrible.

The advantages of Otto's are:
- It affects the target automatically, and they have to waste an action to try and save on their next turn, therefore losing one turn guaranteed(even with legendary resistances).
- It gives you advantage to all attacks, tasha's hideous laughter makes the target fall prone, which gives advantage in melee attacks but disadvantage in ranged attacks.
The main point is the "guaranteed turn skip, even against legendary foes", and advantage in attacks at least until they have their turn.

i suppose, but is it really worth the sixth level slot?

Ah yes, the TikTok spell.

because legendary resists are a thing and so are people with high saves. With this spell, unless the enemy is straight up immune to charms, you have one turn to wail on them before they can do anything about it. You could make a ******* Ancient Red do the hokey pokey for 6 seconds and there is nothing it could do about it. If it chooses to stay in place and attack at disadvantage instead of freeing itself, good it has the same option again next turn, and your party keeps their advantage to attack it.

To those thinking this is weak you have to consider the importance of it automatically working despite legendary resistances. Picture a party of high level going against say an Ancient Red Dragon. If I can cast this spell twice, so am 13th level, I've given everyone advantage and doubled our crit chance to the point in those rounds the paladin or rogue is very likely to crit at least once between them to get a critted sneak attack or max level smite, and the rogue doesn't have to worry about positioning for sneak attack. Your wizard / sorcerer is almost guaranteed to hit dex saves now, unless it wants to burn even more legendary resistances. I've fixed one of the biggest problem with dragons which is their flight, and made it so the dragon had to waste two actions and potentially legendary resistances. That's the equivalent of two surprise rounds that's guaranteed. It does fall off at high levels and vs things like fiends because most things are immune to charms but still great mid to high level spell!