How Do You Run a Doppleganger?

[Mark]

I think this is one of the toughest DMing feats to pull off successfully at the game table. There's a fine line between withholding information the PCs would have and keeping it secret enough that a doppleganger can do what it is meant to try and do. This is particularly difficult if there is a PC involved.

So, how do you run a Doppleganger?

 

[lejanius]

For me there are only 2 ways to do this.

1. Player cooperation: tell the PC what happened and tell them to keep playing their character with some minor differences (such as things the doppleganger wouldn't know about or do). Give them some guidelines and see how long it lasts. This is my preferred way but it does require the player to go along, which for some parties may not be possible.

2. No-Player Cooperation: This one is tougher and can be handled in several ways. you can have the player "miss" a session or two and run his character, you can keep him in the dark after he goes missing and physically remove him from the other players and run two groups, one with the solo player and one with the other party members and when the doppleganger returns to the party you play the PC while he is out of the room (this has all kinds of problems). You can let the PC control his character without him knowing he is a doppleganger (he is attacked, wakes up and is a doppleganger and doesn't know it). When the time is right you spring the trap.

I am sure there are more but this is a tricky situation to handle

 

[ExploderWizard]

Any party that does not develop a doppleganger password/ coded question-response for use every time someone in the party is out of sight of the rest of the group is asking for a doppleganger TPK.

 

[Umbran]

Any party that does not develop a doppleganger password/ coded question-response for use every time someone in the party is out of sight of the rest of the group is asking for a doppleganger TPK.

That works for 4e. In 3e the Doppelganger has Detect Thoughts - it catches a PC, reveals what it is, and then asks "What's your password?" Like it or not, the password floats to the top of the PC's thoughts, and now the Doppelganger knows it....

 

[ExploderWizard]

That works for 4e. In 3e the Doppelganger has Detect Thoughts - it catches a PC, reveals what it is, and then asks "What's your password?" Like it or not, the password floats to the top of the PC's thoughts, and now the Doppelganger knows it....

Well at that point a thinking PC doesn't make the monster use its ability at all. The new password becomes "MONSTER!!" which the PC shouts as loudly as possible.

 

[tyrlaan]

For me there are only 2 ways to do this.

1. Player cooperation: tell the PC what happened and tell them to keep playing their character with some minor differences (such as things the doppleganger wouldn't know about or do). Give them some guidelines and see how long it lasts. This is my preferred way but it does require the player to go along, which for some parties may not be possible.

2. No-Player Cooperation: This one is tougher and can be handled in several ways. you can have the player "miss" a session or two and run his character, you can keep him in the dark after he goes missing and physically remove him from the other players and run two groups, one with the solo player and one with the other party members and when the doppleganger returns to the party you play the PC while he is out of the room (this has all kinds of problems). You can let the PC control his character without him knowing he is a doppleganger (he is attacked, wakes up and is a doppleganger and doesn't know it [nothing cooler than the looks on the other players' faces when he turned around and attacked them mid-battle]). When the time is right you spring the trap.

I am sure there are more but this is a tricky situation to handle

Definitely the first route here. I wouldn't even entertain number 2 because it infringes on player control of their character, which to me is a big no-no.

I have done the first scenario to great success actually. In a Champions game I ran, I had a villain that could copy appearances and powers. I approached one of the players and flat out asked him if he'd be up for getting his character swapped out with a doppleganger. He loved the idea and we worked out the particulars from there (he gave me a way to get his character away from the group to get captured, I told him what his villainous mission would be, and I told him what signal to look for when I wanted him to betray the group).

It was pure awesome, and really I have to tip my hat to the player for making it so cool. He RPed it flawlessly, asking unusual questions to collect intel and the other characters and so on. It was truly a blast to play out.

So my recommendation would be to collaborate with a player you think would be up for it. Also, make sure you dot all the Is and cross all the Ts regarding how the doppleganger makes the swap and what possible hints the players might be able to notice to realize its a fraud. Basically, button up the plot points and little details so you don't end up with a moment later one where a player feels they should have had a chance to figure it out and it was denied them.

 

[Umbran]

Well at that point a thinking PC doesn't make the monster use its ability at all. The new password becomes "MONSTER!!" which the PC shouts as loudly as possible.

And if the Doppelganger is so stupid as to do this where/when the rest of the party is within earshot... well, it gets what it deserves.

Though, you will get the short-lived fun of the party running up to find two copies of their friend fighting each other. Both know the password (or the answer to any question they'll put to it, from the real PC's mind). Good for a few laughs. Just hope the party Wizard isn't Chaotic Neutral - 'cause then just lobbing a fireball at both of them and taking into the party the one tough enough to survive might be the end result

 

[Mustrum_Ridcully]

I think this is one of the toughest DMing feats to pull off successfully at the game table. There's a fine line between withholding information the PCs would have and keeping it secret enough that a doppleganger can do what it is meant to try and do. This is particularly difficult if there is a PC involved.

So, how do you run a Doppleganger?

That's a good question because I am in the middle of using one. Though I am not really interested for a PC. It's an NPC that they are supposed to contact and is part of the same organization the PCs work for.

In this case, they don't really know much about him, so they have little basis to compare him to the original. But he is working "under cover", manipulating events and occasionally using his abilities to appear as another individual so he can sabotage events or hire someone to work for him.

The challenge might be - when do you allow player characters to roll for something, like Insight/Sense Motive or Spot/Perception? Do you use passive checks?

At the moment my challenge seems to be to make the PCs actually figure out who is behind everything. The Doppelganger has already set up a scape goat. There is one "hint"/circumstance that might indicate that the individual that will be accused of betrayal might be innocent, but will it be strong enough? There are already hints of a betrayal (a prophecy by a Vistani Oracle), but this might just make them more determined to pick the first suspect that they find.

Well, we'll find out.

For a player character, I think it might work best if the player itself knows about it. Not every player is suited for that, but it can be great fun to be working against the rest of the players.

 

[Janx]

for an NPC, I'd probably roll some checks for the PCs to detect/sense something wrong for each interaction. Depending on the result, I'd leave a clue or blatantly tell them something's wrong with the NPC. If the NPC passed the test, I'd try to protray him normally, so the PCs don't suspect.

for a PC, you've got multiple problems to overcome. Firstly, is the initial swap. Handling it off camera and "forcing it" is obviously the easiest. As somebody said though, it does reduce player freedom. I'd consider this tactic for a player who missed a session (as its great time to make it happen, wasn't at the game) and he was going to be NPC-tized anyway.

Handling it in a private 1 on 1 session is "more gamist" but it is fair. Its also puts at risk because the player actively knows, and may be MORE resistant since getting swapped means his PC failed/died.

Once the swap is done, you've got the issue of player knowledge and portrayal of his PC. One method, the player never knows, and all the "evil" gets done off camera. I used this method for a player who I needed to portray a NPC posing as a PC. I needed the NPC to do somethings off camera (long term stuff), and having the player use him made him seem more "innocent". The player had agreed to this, as his real PC was in a forked campaign anyway. By not having the player portray the NPC side of things, his secret actions never came up during the game as "he's up to something, lets not trust him". I don't actually recommend this method as a primary solution.


The obvious method is to hand a player a note saying he's a doppelganger. I'd actually consider lying to the player and saying he's "possessed". This way, the player thinks his PC is still OK.

In any event, if the player knows, you need some leverage to make sure he doesn't give it away or play poorly. Consider giving an XP award or penalty for this or the next PC when the current problem is solved if the player does it well. Also, rather than killing the real PC, have the PC in statis/hostage somewhere. The Doppelganger is keeping him alive for future consultation. You can then tell the player that his PC's fate depends on how well he plays the doppelganger. If he does badly, the PC was killed during the swap. If he does well, the PC is a hostage and can be saved.

 

[Eccles]

My bard got doppel'd in the Age of Worms SH I wrote. It was irritating. The doppel knew everything I did, but didn't have any of my abilities. It had pinched all of my equipment, and I ended up playing it for 3 weeks of sessions.

I had to go deliberately go out of my way to fail Fort saves on alcohol abuse to avoid singing (as the doppel had no perform skill), and eventually the doppel died failing a balance check that my 'normal' character would've passed without breaking a sweat. Very silly.

But probably worth it when the dead bard decomposed instantly into dead-doppel shape... Everyone else got very cross at me then...