Recurring doppleganger - how do I?

[roytheodd]

I'm going to be introducing a doppleganger into my game as a recurring villain and I'm wondering just how to make it be slowly discovered, rather than just dropping it into their laps. Let me explain...

There is a small village that is being visited by the ghost of dead twin girl. The ghost wanders down from the cemetary accompanied by 6 skeletons and it approaches the family of the dead girl asking to be reunited. The living twin has been married off to a man in another village. The PCs are called in to try to chase off the ghost. The ghost is actually a doppleganger and it's creating a diversion so that moonrats (from MM2) can carry off a particular infant from the village, thus perpetuating the greater story.

I'm hoping that the doppleganger lives to fight another day (and thwart the PCs a few times before dying), but I'm wondering how I can make the PCs realize that it's the same guy dogging them? I was thinking of giving it an eye that is half brown/half green and that cannot be altered by its skin-changing. I've also thought of giving it a characteristic walk or perhaps an item (ring?) that doesn't change with its appearance - some sort of "mark".

My issue, though, is mechanical. Should I have the PCs make a spot check or memory check or something to notice the mark? I was thinking of describing the guy (and other NPCs) in a certain level of detail so that the players can make the mental connections, but I'm afraid they won't, or that they will but too fast (and then metagame, yeesh). I was also thinking of just mentioning to one of the brighter characters that, upon their third encounter with the guy, they notice the mark. So, any advice on this one?

 

[WillieW]

Be subtle. Rather than a mark on the doppleganger, maybe it drops some small item during its escape. Think of the old B&W detective movies... a book of matches leads to a club....

Items which identify the creature as corporeal rather than ghostly will also arouse the PCs' suspicions and curiosity, without pointing them obviously towards the doppleganger identity.

Where is the doppleganger's lair? Does it have any peculiar smells or does the monster track clues out of the lair when it emerges to have fun?

Make the PCs work -- add tiny pieces of seemingly unrelated clues to make a jig-saw that eventually reveals (a very little at a time) that all is not what it seems.

 

[Piratecat]

How about a stutter on a single word, or a reoccurring hand gesture?

 

[seasong]

Hand gesture is good . Just make sure not to use it with anyone else, unless you want them to jump that person .

Personally, I'd give the doppleganger a magic charm that they keep on them, something like a ring that conceals their motives/alignment.

And just let the PCs catch on to it on their own. If they don't by the time it's critical, then you can ask for perception rolls to tell them the similarity.

 

[roytheodd]

Thanks all - I appreciate the feedback!!