How do I handle a shapeshifter in disguise when the players go into "everyone's a doppelganger, let's murder everyone" mode?

Question

I ran into issues with shapeshifters since, after the first encounter with one, the players turned into "everyone is doppleganger in disguise" mode, which makes using their trademark ability pointless. Because of the story setting, players are trying to infiltrate and stop some event in one castle, the whole thing being set in the past. Hence they do not have any motivation to keep anyone alive because "it was 2K+ years ago and from the history records no one wrote about some group which killed all the cooks in that castle one night".

That being said, using a shapeshifter disguised as some servant is problematic since PCs would just knock him unconscious because "he is a level 1 minion NPC". Since the shapeshifter is certainly NOT a lvl 1 NPC minion, there is a chance he would resist the at-will power one of the players would use to knock him out (not to mention he would have more hitpoints so he would not go unconscious), immediately making the players kill him because "a lvl 1 minion wouldn't resist my spell so it must be a shapeshifter and we will kill him".

I am not happy about this approach but I do not know how to prevent it.

My idea was to give ordinary NPCs some stats too so the players could not abuse their knowledge of mechanics. This was however not a popular solution and I had to defend why the servant (who was this time really a shapeshifter trying to roll with the party for a while) resisted the spell which should have hit him if he was lvl 1 minion.

Is there any good way how to solve this issue? I would like to use shapeshifters in disguise to enhance the story but current players' mindset makes it really troublesome if they mostly attack on sight without the interest of taking any NPC along.

Answer 1

You have several options here, all of which include changing the players' tactics and/or changing your own.

1. Enforce consequences for the PCs' murderous behavior
   If someone came into my castle and started murdering my cooks, I'd have my guards after them so fast they wouldn't see it coming! Just because it wasn't in the written records doesn't mean it didn't happen, especially if the written record is two thousand years old. The castle lord should respond reasonably to having a bunch of murderhobos running around his castle. Putting consequences to their actions should help encourage the players to be less aggressive about meeting new NPCs, which in turn should alleviate some of the problems with their "if I can knock it out it's a servant, if I can't it's a monster" mindset.

2. Give the party a reason to bring along an NPC
   Maybe the party's goal is blocked by an enchanted doorway that will only open for a specific person. Maybe they can't find their way around the castle and need a guide. Maybe they need a hostage to deal with the guards who are coming after them for attacking servants. Whatever the reason, make the players realize that they need one or more NPCs alive and cooperating with them.

3. Give your NPCs some teeth
   You mentioned you tried giving your NPCs some stats, but it's not clear from your question why this didn't work. Not all NPCs should be level-one minions, regardless of what your players want. Guards will have a few levels in some melee- or ranged-weapons class; people in robes are wizards or sorcerers on retainer; the nice woman in a simple dress is a humble but powerful cleric; the nobles are trained in the fighting and/or arcane arts as part of growing up rich. You should also check the various Monster Manuals for low-level commoners - usually these show up under keywords like "cultist" or "guard", but if you reskin them to wield butchers' knives instead of swords, or broomsticks instead of staves, you've got perfectly good servants whose lifetimes of backbreaking work mean they're tough and strong and perfectly willing to fight back when attacked. Once your players get used to the idea that not everyone who isn't a PC or an enemy is a one-HP minion, they'll stop jumping to conclusions based on perceived stats.

Basically, options 1, 2, and 3 are meant to show the players that their current salt-and-burn tactics will cause their mission to fail. They encourage the players to find solutions to problems that don't simply involve a sharp blow to the head. The fact that they also give you more room to use doppelgangers is a handy side effect.

4. Have the doppelganger play along to deflect suspicion
   The PCs knock out everyone they come across? Sure! The doppelganger plays along and pretends to be unconscious long enough to fool the party, then gets back up and goes about its business.

5. Get one of your players in on the doppelganger action
   I did this in my current game and it was beautiful: the PCs didn't think through the consequences of leaving a single guard alone in a hallway in a doppelganger lair, so I sent an IM to the player asking if he'd go along with his character being ambushed, knocked out, and replaced by a doppelganger. The player had a ton of fun playing the doppelganger pretending to be his character, and the rest of the group took considerably longer to clue in because the player was involved in the scheme.

Options 4 and 5 are more about the doppelganger behaving intelligently, plus my favorite DM advice: get the player in on it. The doppelganger wants its mission, whatever that may be (kill the PCs? stop them from completing their mission? something else?), to succeed, and will take reasonable actions to make that happen. Getting one of your players in on this also helps them feel more excited about the plot, and they may even come up with good ideas to fool the other players that you'd never have thought of.

A word of caution: Doppelgangers, by their very nature, will drastically increase the PCs' and the players' level of general suspicion and paranoia. No matter how careful and smart you are about including doppelgangers, you should expect and be prepared for the players to take their own, often drastic, countermeasures. My group, after their one doppelganger encounter, developed the peculiar habit of shooting each other with crossbows to prove they were really themselves.

This paranoia comes because it's frustrating to the players when they can't trust the "rules" of the game world. One doppelganger is problematic enough; when half the NPCs they meet are doppelgangers, the players are likely to lose trust in the DM and the plot (unless you provide a VERY compelling story reason for why there are so many doppelgangers around and impersonating random servants). Once this happens, they're likely to go back to killing everything on sight because they've been burned by doppelgangers a few too many times. I'd strongly recommend being judicious with your use of doppelgangers to minimize this.

Answer 2

thatgirldm wrote a great and thorough answer for your particular problem, but it seems to me like you're trying to treat a symptom rather than the larger problem - which is that your players are metagaming.

First, is the campaign set in the past (relative to another campaign) or are the characters time-traveling? If it's the latter, another in-game solution could be to have their actions in the past change the future. They might not realize it until later, but you could drop hints to the players that perhaps killing off a dozen people in the past might erase a few generations over time.

However, if the campaign is simply set in the past, you need to remind your players that their knowledge is separate from their characters'. Take a look at this:

"it was 2K+ years ago and from the history records noone wrote about some group which killed all the cooks in that castle one night".

How would the characters know what the history records from several years into the future say about their contemporary world?

using a shapeshifter in disguise of some servant is problematic since PCs would just knock him unconcious because "he is level 1 minion NPC". Since shapeshifter is certainly NOT a lvl 1 NPC minion, there is a chance he would resist the at-will power one of the players would use to knock him out (not to mention he would have more hitpoints so he would not go unconcious), immediately making the players kill him because "lvl 1 minion wouldn't resist my spell so it must be a shapeshifter and we will kill him".

The characters' motives and actions are all based on knowledge they couldn't possibly possess. Your players are playing a video game, you want them to play a roleplaying game. Playing a roleplaying game requires the players to accept and play into their characters' world, and it looks like they can't or won't do that.

There is nothing wrong with not wanting to play a roleplaying game, but it might go against what you wanted to do and require you to rethink your general approach to the campaign, because even if you find a solution to this current issue, I think the disparity between you and your players' mindsets will continue to cause problems down the line.

Answer 3

Another angle is to capitalize on the fact that these adventurers are probably not temporal mechanics majors. Even though the players (and maybe even you) have bought into the inflexible timeline theory, since they're metagaming with it, go ahead and change it up. Heck, even if the players were told that's the way it works, surely it wouldn't be the first time an NPC lied or an in-game text was wrong?

Maybe the timeline is resilient, but not unalterable. So what they've done so far hasn't had any noticable effect on them. But maybe the next non-doppleganger peasant they kill is the ancestor of the person who discovered a particular dyeing method, and as he dies half their equipment changes colors. A few minor changes like that might really make them paranoid about taking any kind of permanent and irrevocable action, like indescriminant killing of the locals. Even worse, maybe only the person who commits the act remembers the previous timeline. Could lead to some interesting interactions:

"No, my trousers were never dark blue. Who ever heard of dark blue trousers?"

"I've always had this long sword. Did you get hit in the head? Why are you acting so strangely? Wait, let me get my crossbow out and check something..."