Exactly what it says on the tin. I might be running a Curse of Strahd campaign in the future, and if I do, I have some alternate rules in mind for running werebeasts.

• to start with, I will have any character with proficiency in Nature or Arcana automatically know that there are multiple strains of the curse, some of which have different rules than others. This will be my hint to the players that I am using alternate rules.
• in line with the were ravens and loup garou from Van Richten's Guide, werewolves have no resistance or immunity to weapon attacks. However, while in beast or hybrid form, they have regeneration which can only be halted by silver weapons or by a critical hit. I decided not to have spells stop their regeneration, as that adds to the martial caster divide.
• the strain of lycanthropy that is common in Barovia is, generally, not transmitted via bite. Instead, there are three ways of transmitting it. The first is being born to a werewolf. The second is via a ritual that must be performed underneath a full moon and which is performed by a werewolf (I'm thinking it would involve a potion that uses werewolf blood, a la Skyrim). The third is pretty straightforward and is listed below.
• Kiril, the leader of the pack, has a unique stat block. I took the gladiator statblock and gave him some loup garou features from Van Richten's, including the Large beast/hybrid form, and he can pass on the condition via bite. Lorewise, he obtained this power from a vestige in the Amber Temple.
• Curing lycanthropy will be easier for born werewolves and harder for turned werewolves. For the latter, the Remove Curse spell will have material components. In theory, players could learn the alchemic formula for this curse removal during downtime, but the campaign is all about Strahd breathing down their necks, so that won't be happening. However, either Ezmerelda or Van Richten would know that the heartstone of a hag can bypass the need for material components. I am changing the hags at Old Bonegrinder to be green hags, but I am altering their statblocks somewhat and also giving the eldest one a heartstone which she can use to enhance her own powers while it is on her person. For born werewolves, the cure is the same, it just needs a 6th level spell slot to pull off.
• If Zuleika is the party's ally OR if one of the treasures is in the Werewolf Den, I will add an optional sidequest, inspired partly by Lunchbreak Heroes. Both Zuleika and Emil were taken from the same Forgotten Realms town many years ago, and while Zuleika has taken well to her new existence, Emil has not. Being too vocal about it is why he was "arrested". However, instead of being in Castle Ravenloft, he is being held in the guard tower of Tsolenka Pass. Ezmerelda can be persuaded to use her Tarokka deck to search for him, much to her chagrin. If the party ignores Zuleika but needs something from the treasure hoard, she will warn them about the curse. She can retrieve items from the hoard freely, but will demand the party's help in rescuing Emil.

Quote from Thucydides >>

• in line with the were ravens and loup garou from Van Richten's Guide, werewolves have no resistance or immunity to weapon attacks. However, while in beast or hybrid form, they have regeneration which can only be halted by silver weapons or by a critical hit. I decided not to have spells stop their regeneration, as that adds to the martial caster divide.

 I did that immediately, because making the martial PCs completely useless (no magic or silver weapons on them, they were just starting out) irked me, and making people actually figure out "how do we apply silver to these werewolves" (answer: they had silver coins and improvised) was fun.

Yep. I am allowing critical hits to work so no fight becomes hopeless, since melee attacks against a downed enemy auto critical. A werewolf should be a horrifying threat to townsfolk, and a reasonable challenge to player characters.