Doppelganger vs. Lycanthropy

[DeepShadow of FoS]

I'm teasing an adventure idea, and it hinges on this question: what would happen to a doppelganger who drank an alchemical purgative that contained a curse of lycanthropy?

Obviously dopps are normally immune, but would they be immune via purgative as well? What are your thoughts?

[The Lesser Evil]

By the rules, no. The feat description for spiritual purgative says the secondary subject must be "one capable of being afflicted by the curse". However, the Dark Powers could always make an exception for special circumstances, as always. Alternatively, perhaps the situation becomes one like certain interpretations of Easan: the doppelganger's "lycanthropy" is purely in its own mind. Meaning the doppelganger believes itself to have become a lycanthrope and thus shows symptoms similar to those of lycanthropy. (For example, transforming into forms mimicking the hybrid aspect of a lycanthrope.) Being a purely psychological malady, this would of course mean the original curse would go back to the primary target, possibly causing confusion and strife to all parties involved. Among possible reactions, the doppelganger could be outed as such (if sufficient knowledge of them are know + other possibilities ruled out). Or the alchemist might be accused of being a fraud or a quack.

[DeepShadow of FoS]

Okay, so I guess my question is, what makes a doppelganger immune to lycanthropy? I browsed the Dopp netbook and the Zherisia gaz and haven't seen an explanation.

[Igor the Henchman]

If you want a shapechanging werewolf, why not simply use a wolfwere?

[DeepShadow of FoS]

If you want a shapechanging werewolf, why not simply use a wolfwere?

Well, regardless of whether it's a doppelganger, the adventure requires that someone have lycanthropy forced on them who didn't have it previously.

[The Lesser Evil]

Okay, so I guess my question is, what makes a doppelganger immune to lycanthropy? I browsed the Dopp netbook and the Zherisia gaz and haven't seen an explanation.

In game rules, doppelgangers are Monstrous Humanoids or Monstrosities, depending upon your ruleset. 3e does not give us much description on them, but 5e gives us that monstrosities are neither ordinary or natural. Some other setting lore (e.g. the Forgotten Realms) have artificial origins. Of course, this at best refers to outlander doppelgangers, rather than the dread doppelgangers that populate Land of Mists whom may or may not have similar origins. It may just be that their physiologies and psyches are so alien that lycanthropy doesn't apply to them. Put simply, they can look and emulate us, but that does not mean they are us. VR's Guide to Lycanthropy brings up racial susceptibility to certain lycanthropic strains. Doppelgangers, having no constant humanoid physiology, might have total immunity from lycanthropy.

Alternatively, perhaps they have such fine control over their shapes that lycanthropy has little efficacy over them. VRG to Doppelgangers says that the rubberiness prevents permanent scars and the like (p26), and they are also described as having precise control over physiological functions such as the heart and circulatory system (p29). So together perhaps the infectious disease component can't take hold.

Or if you want, we could delve into setting lore, we note that Paridon has no native monsters (Other than their native shape changers, of course.) It could be that Paridonian doppelgangers weeded out werewolves in the native population a long time ago, including any of their own that could succumb to the disease. This would effectively make immunity to lycanthropy an acquired one over generations.

If you wanted an in-character theory about it, the Celebrants of Humanity in seeing doppelgangers as unfortunate diseased aberrations of normal humans could say that one malady precludes the other. Perhaps some might even view the doppelganger as a more advanced case of lycanthropy. A "were-human" as it were!

(Of course, I"m not intending all of this nitpicking, explanations, and speculation isn't meant to get in the way of a good plot)

Edit:

If you want a shapechanging werewolf, why not simply use a wolfwere?

Well, regardless of whether it's a doppelganger, the adventure requires that someone have lycanthropy forced on them who didn't have it previously.

Perhaps it could be the misbegotten result of Celebrants of Humanity research on doppelgangers and trying to turn them human, effectively creating a new form of lycanthropy affecting doppelgangers in their research?

[Igor the Henchman]

If I had to come up with an answer in my own game, I would make the doppelganger become able to assume the form of beasts in addition to those of humanoids, but at the same time suffer from bouts of uncontrollable hunger or bloodlust.

Depending on what the adventure is going for, the creature could revel in its new powers, or it could start desperately seeking a cure. After all, doppelgangers as a rule hate not being in control of themselves, hence Sodo’s curse.

[SkiBird]

I like the psychological affliction angle.

Taking it a step further ... what becomes an afflicted doppelganger when the change is upon him? Do they ... change into a blood-crazed animal? A blood-crazed hybrid animal? Yawn. That's what happens when humanoids are afflicted with lycanthropy. If everything is same same ... then it is not sexy. Let's make it sexy.

I think it would be neat to explore what a 'lack' of changing would look like. If a natural born shapeshifter received what is ostensibly, a curse that caused them to become a shapeshifter ... well, maybe some sort of double negative thing happens?

So like, they still lose control of themselves, perhaps even go more than a little moon crazy. But the doppelganger that had been impersonating the local lord? Well he just tears his clothes and gnashes his teeth and launches into someone's jugular ... all while maintaining their guised form. I feel like this would lead to a terrifying scene.

Or maybe these afflicted doppelgangers could lose the ability to change unless and until the moon is upon them. Their inborn shapeshifting abilities calcified in some fashion. Blocked. Ever present, but always just out of reach. A being that went from always able to express themselves in a fluid, ever shifting dynamic that they had always known ... becomes a creature that — like the rest of us — is always trapped in its own skin. What other sorts of psychoses might manifest if a mutable creature found itself involuntarily immutable? What lengths might they go to to see the curse undone?

[And yeah, agree with previous posters (at least with regard to the 5th edition rules-as-written) forbiddance of lycanthropic curse affecting a doppelganger. The description of curse says it afflicts humanoids and doppelgangers are monstrosities. But the rules only exist to set a framework ... it is sometimes the exceptions to those rules where the magic happens.]

[DeepShadow of FoS]

Thank you all for your feedback. The adventure hook is developing in a different direction, but this was helpful to get my juices flowing.