I'd like to clarify whether were-creatures need to do damage in order to have a chance of inflicting the lycanthropy curse.
Considering the creature stats in isolation it would appear the answer is no.
E.g. For the werewolf (all other lycanthropes are similar):
Bite ... Hit: 6 (1d8 + 2) piercing damage. If the target is a humanoid, it must succeed on a DC 12 Constitution saving throw or be cursed with werewolf lycanthropy.
From the above, the possibility of being afflicted applies whenever the bite attack hits. So if damage reduction or immunities kick in, and the target takes zero damage, there's still a possibility of getting the curse.
However, page 206 of the MM also states:
Curse of Lycanthropy. A humanoid creature can be afflicted with the curse of lycanthropy after being wounded by a lycanthrope.
The keyword here is wounded, which implies that the attack must actually deal damage. The problem though, is that as far as I can tell: wounding isn't established in game terminology. Can we assume it really is synonymous with damage
> 0? Or am I reading a little too much into the explanatory text?