Can lycanthropy be sexually transmitted?

Question

I have a player in D&D 5e who is a Blood Hunter under the Order of the Lycan. He wrote a backstory, as all my players do, and in it said that after becoming a werewolf, he had a wife and child. I’ve researched through D&D studies and mythical lore, and found that the child he had could be born with lycanthropy. I am a very thorough DM and just want to know, without judgement or immaturity:

Can lycanthropy be sexually transmitted?

I just need to know if his wife became a werewolf, because it could affect the story later on.

Answer 1

Lycanthropy can be passed down to children, but isn't mentioned as sexually transmitted

The Monster Manual entry on lycanthropes (p. 206) says:

Curse of Lycanthropy. A humanoid creature can be afflicted with the curse of lycanthropy after being wounded by a lycanthrope, or if one or both of its parents are lycanthropes.

There is no mention of lycanthropy being passed on to sexual partners. In particular, the phrasing "if one or both of its parents are lycanthropes" suggests that sexual contact won't usually transmit the curse of lycanthropy, unless sex always leads to children on the first try - otherwise, both parents would be lycanthropes as a result of having sex, so it wouldn't be just one parent.

The only ways mentioned to pass on the curse of lycanthropy are:

• being wounded by a lycanthrope (most of the statblocks show that it's transmitted by a bite or a similar attack)
• being the child of a lycanthrope

A cursory online search (including the Wikipedia article for lycanthropy in D&D) indicates that these two methods are the only ways of passing on the curse as described in previous editions of D&D as well. (According to the Forgotten Realms wiki entry, the 4th edition Monster Manual has it only as a hereditary condition.)

Anything beyond what's stated in the quoted entry would be up to you as the DM. I don't think it'd cause any mechanical problems to have lycanthropy be sexually transmitted if you wanted it to be, though there might be some narrative consequences (lycanthropes might be reluctant to have sex for fear of passing on the curse - or they might only do so after revealing their true nature to their partner).

Answer 2

Theoretically, yes, lycanthropy can be transmitted via these encounters.

According to the 5E Monster Manual, lycanthropy is commonly transmitted by the natural weapons, such as bites or claws, that the lycanthrope has in their hybrid or animal forms. Page 206 has the general description for lycanthropy, which is technically a curse:

Curse of Lycanthropy. A humanoid creature can be afflicted with the curse of lycanthropy after being wounded by a lycanthrope, or if one or both of its parents are lycanthropes.

And a bit later, describes how a lycanthrope can pass the curse onto a non-lycanthrope:

A non-lycanthrope humanoid hit by an attack that carries the curse of lycanthropy must succeed on a Constitution saving throw (DC 8 + the lycanthrope’s proficiency bonus + the lycanthrope’s Constitution modifier) or be cursed. If the character embraces the curse, his or her alignment becomes the one defined for the lycanthrope. The DM is free to decide that a change in alignment places the character under DM control until the curse of lycanthropy is removed.

Let's not judge what a consenting couple does in the privacy of their time spent off-screen. Biting may occur, respectfully and without causing damage (which is not needed to pass on the curse), and could therefore pass the curse onto their partner.

Note that the Blood Hunter is not an official D&D creation, in case Order of the Lycan has its own lore behind the science of lycanthropy. Then again, you're the DM of your campaign, and ultimately you can decide how the lore works.

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Answer 3

Technically maybe, effectively probably

Again going to the monster manual text:

Curse of Lycanthropy. A humanoid creature can be afflicted with the curse of lycanthropy after being wounded by a lycanthrope, or if one or both of its parents are lycanthropes.

The answer thus depends on your concept of "wounded". Assuming a conservative interpretation of this wording, let's assume you need to draw blood by direct physical contact.

Thinking about the biomechanics of humanoid intercourse (and attempting to take the most mature tone possible to describe these concepts), if there was an extreme volumetric mis-match in their respective biologies favoring the husband, it would qualify. In addition, if they ever had a particular passionate lovemaking during which time he scratched or bit just a bit too hard (easily possible given his nature), this also qualifies. It's also possible she'd have wanted to be like her husband to support him, and asked for a small scratch to effect the change.

So... generally speaking, if the husband is a lycanthrope, the following conditions must be met as part of their intimate details for the wife to not gain lycanthropy:

1. They were of compatible physical dimensions.
2. Their lovemaking was not particularly passionate, or they were just careful to avoid scratches given the wilder nature of the husband.
3. Either she did not know he was a lycanthrope or did not wish to become a lycanthrope.

Note that all four are more than possible. It is not a guaranteed thing, but if any of these was an established part of his described backstory (not sure and do not wish to know how detailed he got), then that would provide a definite answer.

Answer 4

If it can be transmitted via a wound then the chance of it being transmitted sexually would almost certainly exist. This is a documented path for disease to be passed in humans during sexual activity; sex with a lycanthrope would seem to only increase that possibility.

Being bitten by a person with HIV. Each of the very small number of documented cases has involved severe trauma with extensive tissue damage and the presence of blood. There is no risk of transmission if the skin is not broken.

https://www.hiv.gov/hiv-basics/overview/about-hiv-and-aids/how-is-hiv-transmitted

There’s additional detail on the .gov site that some people might not find appropriate to quote here.

Secondly, while there’s no rule that says lycanthropy can be passed via sexual transmission, there’s no rule that says it can’t either - frankly, I’d be surprised if they HAD decided to address sexual transmission in the rule books. So that said, if lycanthropy can be passed to a child then it has to be present (in some form) within the female. If you’re trying to add a touch of realism it seems unlikely that a non-genetic disease that can be passed to offspring cannot also be passed via sexual activity.

Since this specific issue is not addressed by the rules, I think it’s up to the DM to apply the rules as they make the most sense including to advance the storyline.