I’ve been watching a lot of Fringe lately, and one of the things that is so weird about the show is how nonchalant they are about infiltration by doppelgangers. Despite (SPOILERS) an antagonistic parallel universe with perfect duplicates and a whole bunch of shapeshifting assassins (/SPOILERS) they never really adopt any reasonable level of paranoia about checking important people to make sure they are who they say they are. Players in an RPG where they knew there were doppelgangers trying to infiltrate their organization would be much more paranoid.
So this is a simple idea for mind games to play on PCs in a one-shot or otherwise short-term campaign. The idea presupposes the following:
- The PCs are important agents of the same organization, and an enemy is employing doppelgangers to infiltrate the organization.
- There is no easy way to differentiate doppelgangers (either because they’re true alternates or highly effective shapeshifters): physical checks, scans, mental probes, and so on are unable to differentiate the fake from the genuine article. There might be something obvious on an autopsy, but then you have to kill a suspected doppelganger. The organization may be working on a better test on a live suspect, but it’s still some ways out from being viable (i.e., not within the scope of the campaign or not until the climax).
- Doppelgangers can gain a significant portion of the memories of those they replicate, either through extremely careful research or some kind of memory leeching. Thus, only the most careful questioning of a suspect by someone very close is likely to turn up discrepancies. And doing so will probably waste valuable time and turn up false positives.
Essentially, the goal is to create a climate of distrust between the PCs like in the board games for Battlestar Galactica or The Resistance: if you want to catch the traitor before he or she ruins everything, you have to second guess everything your allies are doing.
Make cards similar to the ones below (with details changed to fit what’s actually going on in your plot). Either hand one out to everyone at the start of the game, or stagger their handout until PCs are away from the group (e.g., going home to sleep for the night).
You’ve been replaced by a doppelganger. Continue to play your character normally.
The body of your original is dead from [standard method of killing] where you duplicated it. You’ve stashed the body in the most secure area, but you’ll need a whole evening without anyone paying too much attention to properly dispose of it. Until then, its presence could give you away. Your mission is [primary mission]. Your secondary mission is to protect other agents of the conspiracy, particularly [leader]. Attempt to help other agents escape, but only if it will not compromise your cover and your primary mission. If [leader] is in danger, you should risk your cover and mission to ensure [his/her] escape and survival. You know everything that your original did at the time of replacement, with some limitations. You can answer correctly any question put to you, unless it begins with “How” or “Why.” In those cases, attempt to deflect or get the questioner to rephrase; otherwise any answer you give must be wrong. Hand this card back when you have privacy and want to call in to the conspiracy to report everything you’ve learned so far. |
You were almost replaced by a doppelganger! A perfect duplicate of you jumped you, and you just barely won the fight and killed it.
There’s a dead body where you were jumped that looks just like you, but wearing simple black clothing. It’s up to you what you want to do with this body. It’s possible that the conspiracy thinks you’ve been replaced, but you don’t know any protocols for pretending to be your doppelganger. Before dying, your double said, “[something mysterious that will be relevant to the plot later].” Whenever you think you understand the significance of that phrase, hand this card back. If you are correct, you’ll automatically gain [significant bonus based on system] to your next roll dealing with the conspiracy. |
Your boss, [NPC boss name], met with you away from your teammates. [He/She] thinks that the department is being infiltrated by doppelgangers, and has vetted you as trustworthy.
Your job is to keep an eye out for infiltrators within the group. Hand this card back when you think you’ve identified a doppelganger and want to call in a team to capture him or her. Keep in mind that they may attack to kill if there’s any doubt, so you may be signing the death warrant of a genuine teammate if you’re not certain. |
You feel like you’re being watched.
Whenever you’re alone, you’re seeing pursuers out of the corner of your eye. They disappear when you turn to look. Maybe you’re just going mad from the paranoia? Or maybe you’re not paranoid enough. Hand this card back to get a [significant bonus based on system] to initiative and to automatically avoid being surprised as soon as you are jumped by agents of the conspiracy. |
You get an excellent night’s sleep and wake up well rested.
Hand this card back to get a [minor bonus based on system] to any roll the following day for being so sharp and focused. |
You stumbled across a strange [radio/computer program/phone/etc] within the office that may be a method someone is using to communicate with the conspiracy. You’ve already gotten one message from it: [something mysterious that will be relevant to the plot later].
You can either turn it over, or hang onto it and hope that it presents other information (hoping that they don’t know you have it). Whenever you think you understand the significance of that phrase, hand this card back. If you are correct, you’ll automatically gain [significant bonus based on system] to your next roll dealing with the conspiracy. |
You’ve been replaced by a doppelganger. Continue to play your character normally.
The body of your original is dead from [standard method of killing] where you duplicated it. You’ve stashed the body in the most secure area, but you’ll need a whole evening without anyone paying too much attention to properly dispose of it. Until then, its presence could give you away. Your mission is [primary mission]. Your secondary mission is to protect other agents of the conspiracy, particularly [leader]. Attempt to help other agents escape, but only if it will not compromise your cover and your primary mission. If [leader] is in danger, you should risk your cover and mission to ensure [his/her] escape and survival. However, you’re having second thoughts because [reason doppelganger might want to abandon the conspiracy]. You’re just a grunt and were deliberately not told much information about the conspiracy, and they’d try to kill you if you revealed yourself. And who knows what the organization might do? You know everything that your original did at the time of replacement, with some limitations. You can answer correctly any question put to you, unless it begins with “How” or “Why.” In those cases, attempt to deflect or get the questioner to rephrase; otherwise any answer you give must be wrong. Hand this card back when you decide to go directly against your mission (expect quick reprisal from the conspiracy’s agents). |