Does a magical creature's sounds mimicked by a kenku have the same effect as the real sound?

Question

One of the antagonists in my plot is a kenku scientist. The party has met her a couple of times and is more and more disturbed with her experiments. She had accepted her curse and the fact that she cannot speak of her own accord. So she makes the best of it and studies the speech of others, with a special focus on the sounds of different dangerous creatures.

The party will face off against her and I plan to use a plethora of harmful sounds in this fight (utilizing the kenku’s mimicry trait), for example a harpy’s Luring Song, a gibbering mouther’s Gibbering and a banshee’s Wail. Now I would like to know, if this would actually work the way I want. (Which means, that the party would have to make saving throws against those abilities). I know, that I can do whatever I want as a GM and that my word is law. But I’d like to keep things logical and consistent, and I’m not sure if these imitated sounds would have the desired effect. I have some arguments for it and against it.

Does a sound mimicked by a kenku have the same effect as the real sound?

(I know that according to the rules, they cannot copy features from other creatures with their mimicry. Otherwise it would say so. This question is more focused on whether this would make sense in an in-universe context).

Answer 1

They probably won't have the same effect.

As you said, a strict RAW ruling will have to be negative, so all I can offer is my take on it.

Mimicry.

You can mimic sounds you have heard, including voices. A creature that hears the sounds can tell they are imitations with a successful Wisdom (Insight) check opposed by your Charisma (Deception) check.

While the Kenku can replicate the sound, they are probably not able to replicate the whole experience, the power and stuff like that. They just don't have the same physiology (or magic). And even the replicated sound is a distinguishable imitation, not a perfect copy.

Imagine it as a difference between a whale song, or a roar of jet fighter passing by, or a wind rustling leaves around you versus a recording of it. It "sounds" the same, but it isn't.

Moreover, in the case of Harpies, the melody is magical (Kenku can't do that), the Banshee's wail give psychic damage, not thunder (so it's not reaaaaly sound/voice based).

Answer 2

Make it a Lair action

Hang a lantern on it. Your players will know it's not RAW and unless there is a narrative explanation for why THIS kenku can do this but others cannot, it can damage verisimilitude and immersion.

On the other hand, this sort of thing sets precedents, and you'll want some way to make sure that the PCs don't get their hands on the same trick, or they'll want to steal the song of, say, a Night Twist and combine it with others, to creative but broken effect.

But this does sound like a very cool antagonist... so my suggestion would be to find some way to make this work for this Kenku in this place, but nowhere else. Perhaps it could be something the Kenku has set up in her lab, making the effect a Lair Action, usable only by her in her specifically prepared laboratory, with all the acoustic reflectors, sound amlpifiers, and other nifty things set up to make it work.

If the Kenku is the only one who can make it work, and replicating it would be prohibitive, then it makes for a great scene, but won't break your game with PCs going around effectively able to duplicate the effect of summoning horrible things without the risks.

Honestly, I'd be interested in how the Kenku got all these sounds to mimic. She must have gone on a lot of exciting adventures, seeking out all manner of very dangerous horrors and overcoming them in order to collect her dangerous noise weapons. Is there a travel journal/ research notebook somewhere with this kind of valuable lore in it? Very cool concept.

Answer 3

Does a sound mimicked by a kenku have the same effect as the real sound?

Explicitly not, taking the Monster Manual entry for Kenku. This should also not be an option for players to take by RAW.

This question is more focused on whether this would make sense in an in-universe context

To a large degree, as DM it is your world to say whether the idea makes sense. You are only limited by self-consistency, and in a more minor way consistency with other lore about Kenku. I would say you are in the same position as any new sci-fi or fantasy writer who is writing for an established series. Provided your idea doesn't clash badly with established facts, then it is good to go.

It is hard to prove a negative, and I am not a Kenku expert, but I don't know of any lore that prevents your idea in principle. You might want to kickstart the scientist Kenku's new ability by granting it through some accident or alliance that most other Kenku would not be able to experience in their back-story (to explain why your Kenku is special).

Other than that, official D&D material is full of enhanced creatures that have gained powers through foul experiments or dark pacts. I am playing currently in the Elemental Evil campaign, and that is chock full of customised NPCs that have gained such powers.

You don't need to find official rules or find/create homebrew rules that explain your Kenku's abilities in general sense. You just need to homebrew them as a monster/NPC.

The only game rule I think you need to observe is figuring out the enhanced Kenku's CR, and checking what allies or advantages it is fair to give it in combat encounters in order to be challenging, but not too challenging.

Answer 4

I don't see how this would work with RAW, or even RAI. It's going to take some homebrewing to make it happen.

Take Blood?

I am unfortunately not very familiar with scientists in D&D. However a perusal of the D&D Wiki Homebrew page on Scientist class has an interesting feature called Take Blood, which looks exactly like what you're looking for:

You have figured out that taking blood from any creature or friend, plus adding some more materials will allow you to mix a potion and drink it[. This] will let you gain a feature from the creature’s stats. This effect will last one whole 24 hours[sic][. There is] A 20% chance to poison yourself and take 1d4 poison damage for five of your next turns. This counts [as] a disease.

This is of course a homebrew, but it supplies a decent mechanism for your Kenku doing exactly what you want her to. This also seems in line with a scientist who would perform disturbing experiments; tracking down beasties and somehow taking their blood, or capturing them and imprisoning them for future bloodletting and gory experimentation.

I love the character you've created and the idea of imitating both sound and ability. This is a fabulous and original antagonist, super creepy. Please, please, please find a way to make her work.