The Traitor Player Character

[tchntm43]

Kind of crazy idea I had, I'm wondering if anyone here has ever played in a game where this has been done. Plays like a normal game except the DM and one of the players has secretly agreed that the player's character is secretly working for the arch-nemesis of the campaign. The campaign plays normally through the early levels, with the traitor earnestly befriending and working with the party to accomplish goals, and then late in the campaign at a critical moment, he turns and reveals he's an enemy. It goes to combat and the party has to defeat their former ally. The player who played the traitor, assuming the traitor dies, knows from the start that his time as a member of the campaign ends once his character dies.

I dunno, it seems like it would be a crazy twist that would be well-remembered, but also I think there's a good chance the rest of the players would quit and never play with that DM or the traitor player again.

[Pauly]

I have played in one shots in conventions where one of the PCs was a mole.

It sucked.

1) It breaks the implicit element of trust that all the PCs are working together.
2) It is frustrating for the other PCs as to why the mole isn't pulling their weight.
3) The rest of the party feel betrayed when the mole is revealed.


This is different from Paranoia (everybody is a mole) or Cyberpunk (anyone can be bought) or all evil parties (everyone is out for themselves) because the players know before they start what they are getting into. They understand that the system or genre is built around the possibility that party members will bowb their buddies.

[Jay R]

If I ever did this, I would put all the players in he same situation.

Either
1. Each one has a secret agenda and goal, all mutually incompatible, or
2. Tell everyone this game has one player who is actually playing a traitor, while not really having one.

Both of those ideas have some problems, but all players have the same ones, so at least it's fair.

[Anymage]

Pauly touched on something really big. As an intrinsically social activity that's presumably happening between friends, having to keep your guard up between characters will quite likely require the players to invest time and attention overhead to something other than playing the game, and have a very high chance of undermining the relaxed atmosphere that most players expect when playing a game with their friends. Intraparty backstabbing undermines that, and can make it difficult for the players to get that back later because they've been primed to expect otherwise. The idea is really unwise unless everybody signs on for that sort of game from the getgo.

Also, while the mole being revealed might make for a memorable moment, what then? The player involved will have just lost their character (either due to combat or just due to being unwelcome once they've been figured out), and the party will be primed to distrust any new character the player brings in due to the betrayal. What would you expect the player to do if they want to continue playing in the campaign?

[Satinavian]

I have seen it used satisfyingly exactly once. And a big part of that was that the other players could say in hindsight "Yes, that makes sense and we might have expected it. It is our fault for being too trusting/careless here".

In that adventure the group was after some criminal cabal. And when they finally found out who was the secret mastermind, he was related to one of the characters. So the whole group knew that this character (not involved in the cabal) had now a conflict of interest between family obligations and justice. When she grudgingly seemed to go after her relative but actually then betrayed the group, no one was upset but it did come at a surprise.


However usually it doesn't work.

Because a halfway competent traitor is just too strong. Sabotaging supplies and equipment, raising alarm on stealth missions, inviting enemies when on watch, making the plans of the party with them to ensure weaknesses to exploit, giving the plans to the enemy beforehand, ... a competent traitor will bring the party down and not start a fair fight 1 vs. 4. And the only way to prevent that is to play so paranoid that the party basically gets nothing done. If no plan can ever rely on single party members doing their job properly and without supervision, that doesn't leave much options.

As for social expectations and break of trust, that is another issue. But, honestly, that is similar to treasonous questgivers and other events when the party makes the wrong move by actually taking the only adventure hook the GM provides despite their characters having good reason not to.

[Vahnavoi]

Kind of crazy idea I had, I'm wondering if anyone here has ever played in a game where this has been done. Plays like a normal game except the DM and one of the players has secretly agreed that the player's character is secretly working for the arch-nemesis of the campaign. The campaign plays normally through the early levels, with the traitor earnestly befriending and working with the party to accomplish goals, and then late in the campaign at a critical moment, he turns and reveals he's an enemy. It goes to combat and the party has to defeat their former ally. The player who played the traitor, assuming the traitor dies, knows from the start that his time as a member of the campaign ends once his character dies.

I dunno, it seems like it would be a crazy twist that would be well-remembered, but also I think there's a good chance the rest of the players would quit and never play with that DM or the traitor player again.

It's been done, though I suggest you take a good look at more explicit games of social deduction, such as Werewolf, Mafia, Saboteur, Murder, Among Us etc. to refine your idea of a "normal" game before you proceed. Several key mechanics have to be in place for this to work:

1) Incomplete information. Chiefly, players should not have full knowledge of each other's characters. For example, you can make it a rule that players aren't allowed to show their character sheets to each other, or the player-facing character sheets can omit some key information (such as alliance or alignment).

2) Friendly fire is on. Player characters are allowed to, both by accident and on purpose, harm or even kill each other. All of them, not just the traitor versus the "honest" characters.

3) Player versus player is also on. Even during the phase when player characters are co-operating, how to co-operate is their problem, not the game master's. Corollary being, punishing player characters for not being team players is the player's task. This may mean character who AREN'T the traitor will be killed or expelled by other characters before they even figure out there is a specific traitor.

4) Players ought to have opportunity for private actions and private messaging. For the traitor player, this is necessary, but it should apply to all the non-traitors too and you should encourage them to use the opportunity.

5) You don't control when the treachery is revealed. Gameplay does. You aren't writing a book and aren't directing a movie. You are setting up a challenge for the traitor player (remain undetected to a defined point) with complementary challenge for the non-traitors (realize there is a traitor and figure out who it is). It's up to skill and wit of the players when the critical moments happen, or even if they happen at all.

As further commentary, yes, there are players who would rage-quit a campaign such as this. Yes, some would never play with you again. Those players are stupid, they are playing a faulty meta-game across games. More explicit games of social deduction (Werewolf etc.) will show both why it is wrong and how to get over it: play this type of game more than once. The traitor changes, because being the traitor is an aspect of a player's role, not a permanent fixture of the player. This is relevant even in roleplaying games with no traitor within the party, because even those games typically have one central player who will repeatedly change roles throughout a game: the game master.

This can even be analyzed game-theoretically: the metagame scenario can be likened to an extended Prisoner's Dilemma, and the player who never plays again with the traitor is effectively employing a Vengeful strategy, where a single defection is answered by always defecting back. It can be shown that both basic tit-for-tat (defection is met with defection on case-by-case basis and co-operation is resumed if the defector resumes co-operating) and tit-for-tat with forgiveness (where sometimes defection is met with co-operation anyways to avoid a cycle of revenge) are better strategies.

---

I have played in one shots in conventions where one of the PCs was a mole.

It sucked.

1) It breaks the implicit element of trust that all the PCs are working together.
2) It is frustrating for the other PCs as to why the mole isn't pulling their weight.
3) The rest of the party feel betrayed when the mole is revealed.

Those aren't flaws. Those are the entire point of doing a game format such as this.

Pauly touched on something really big. As an intrinsically social activity that's presumably happening between friends, having to keep your guard up between characters will quite likely require the players to invest time and attention overhead to something other than playing the game, and have a very high chance of undermining the relaxed atmosphere that most players expect when playing a game with their friends. Intraparty backstabbing undermines that, and can make it difficult for the players to get that back later because they've been primed to expect otherwise. The idea is really unwise unless everybody signs on for that sort of game from the getgo.

Completely bogus criticism. In a game with a traitor, keeping a guard up etc. is not "something other than playing the game", it IS the game, and the uncertain atmosphere it brings is the point. Not every game type exist to be relaxed fun times between friends, even if the players ostensibly are friends.

Also, while the mole being revealed might make for a memorable moment, what then? The player involved will have just lost their character (either due to combat or just due to being unwelcome once they've been figured out), and the party will be primed to distrust any new character the player brings in due to the betrayal. What would you expect the player to do if they want to continue playing in the campaign?

The same they'd normally do, make a new character. Other players distrusting new character? They're free to. Whether that is or isn't functional depends on whether the distrust is actually warranted this time. It's a decision about game strategy, one that would be absent if everyone was trustworthy all the time.

[Kurald Galain]

1. Each one has a secret agenda and goal, all mutually incompatible, or

This is the premise of the RPG Paranoia, which I find hilarious (also in part because it's clearly not a serious game).

I also once introduced a group of players to Paranoia by giving them pregens and telling in advance that one of them would be a traitor (with the secret being that all of them were a traitor).

However, outside of Paranoia, I'm sure that this can be done well but I find that it's usually not. And in my experience, this is often a case that one PC is very obviously working against the rest but the others aren't allowed (by GM fiat) to do anything about it. This usually ends up very fun for that one character, and not for the rest of the group. We even once had a Call of Chtulhu campaign where a PC ended up with zero sanity, and the GM declared that this character would now keep playing and be actively opposed to the rest of the group, and we had to convince him that this was a bad idea.

[icefractal]

I don't have much experience with the "actual PvP from the start" variety, but in several games over the years, one of the PCs ends up turning against the party (or vice-versa). In most of those cases, it wasn't really by surprise - other players knew OOC it was a definite possibility - and it wasn't PvP until the reveal occurred or shortly before, since the lone-PC was legitimately part of the group (as in, their goals aligned, wanting them to succeed) before that point.

It hasn't caused any OOC problems, but (when it comes down to a fight) the showdown isn't always that great. The way PCs are set up in many systems, a likely outcome is "kills one of the other PCs and then dies, all very quickly", usually not a very desirable result.

[Zombimode]

It works very well in Free Leagues ALIEN Rpg. But that is a very one-shot driven game where each character has its own agenda that might or might not align with the whole group surviving. One Android is pretty much always expected by the players even if the specific scenario doesn't contain one (or the android character didn't got picked).

And all of this is obviously to reinforce the specific franchise expectations.

[Satinavian]

It's been done, though I suggest you take a good look at more explicit games of social deduction, such as Werewolf, Mafia, Saboteur, Murder, Among Us etc. to refine your idea of a "normal" game before you proceed. Several key mechanics have to be in place for this to work:

What have all those in common ?

- Every player knows there are traitors (often even specifically how many and what they can do)
- Threats outside the traitors are either severely diminished or not even present.

In the "surprise traitor in an RPG" that is generally not the case. The notable exception for games is Paranoia. And this is problematic.

This can even be analyzed game-theoretically: the metagame scenario can be likened to an extended Prisoner's Dilemma, and the player who never plays again with the traitor is effectively employing a Vengeful strategy, where a single defection is answered by always defecting back. It can be shown that both basic tit-for-tat (defection is met with defection on case-by-case basis and co-operation is resumed if the defector resumes co-operating) and tit-for-tat with forgiveness (where sometimes defection is met with co-operation anyways to avoid a cycle of revenge) are better strategies.

that is very wrong.

A player ragequitting and searching for another goup of actually likeminded people is not represented properly by the extended prisoner dilemma at all. This whole analysis is for repeating the same scenario with the same players again and again. If players can leave/do other things/find other groups, it all falls apart. Also, people would probably have more of a grudge towards the GM, not the player anyway.

Completely bogus criticism. In a game with a traitor, keeping a guard up etc. is not "something other than playing the game", it IS the game, and the uncertain atmosphere it brings is the point. Not every game type exist to be relaxed fun times between friends, even if the players ostensibly are friends.

That whole argument only works if the whole table knows they are actually playing a traitor game.
Otherwise the majority of the table plays one game and the GM+traitor plays another. Which of those IS the game ? The one most participants play obviously : not the traitor game.

[Mastikator]

Did this in a one-shot, two players had separately approached the DM to secretly work for the BBEG.

This happened 4 years ago, we were 6 players and one DM. I was one of the players, I was the only player with good alignment.

One ended up double crossing the BBEG. We killed the other one.

The game sucked, for various reasons, but one of those reasons was the 3 players who wanted to play dark evil edgelords (one was greedy and selfish to the point of it being PVP, the other two were literal traitors).

The player who got his treasonous character killed has since learned his lesson and is now a teamplayer. The double-crosser is got a bit better too, I'd say she's tolerable now, but she's still incapable of playing an unproblematic character. The selfish greedy player doesn't play anymore, I can't say I miss him at the table.

It is a well remembered plot twist. But it's not fondly remembered. In fact I explicitly ban that kind of PC in my games, and I always make sure the game is hard enough that if the players don't work as a team they die. Toxic egoistic players will find no safe haven at my table.
It was a learning experience, the main lesson for this thread is: don't do it, don't allow it, if players insist then they may be a problem.

Edit- added context

[LibraryOgre]

I've done it, from both sides, and find it works fine, provided it doesn't become a crutch, and both the DM and the secret traitor are working for FUN, not to win.

If it becomes a crutch... if every time we play, someone is the secret traitor, or if every time Bob plays, Bob is going to betray us... then it's just... tiresome. "Oh, Bob's in this game. I will tell Bob's character nothing, and we have secret meetings without Bob. Because Bob always betrays us." I find the "every time we play" to be a BIT less troublesome, but partially because of games where everyone does have a secret, or at least private, agenda... e.g. Vampire

There's also the griefer aspect... the secret traitor who is just making things less fun for everyone. You not only see it in secret traitors, but also in characters like kender, where the player is playing for their own enjoyment, not the enjoyment of the entire group. "Yes, I stole your fancy Bracers of Defense. I'm a kender, it's totally what I would do." Those players? They never pick up your lucky rabbit's foot, or the pouch of marbles you carry, or your Dragon Chess pieces... they always pick something that would be useful for you, just so they can have done it. Similarly, the secret traitor is often unconflicted about what they're doing, so they can kill you with impunity.

An example for me goes back to Baldur's Gate 2.

Spoiler

Show

At the end of the Asylum, Yoshimo betrays you. There's a degree of foreshadowing of this... the normally brash Yoshimo becomes hesitant, cautious, trying to avoid... something. And then you find out that a) he's been geased by Irenicus this whole time and b) your class being immune to poison doesn't mean you get to, you know, avoid being poisoned for Plot Reasons. Yes, I am salty.

While it's an NPC, it's a major NPC. They've been with you from the beginning. They've helped you get to this point, and then you find out it's for their own purposes.

[Pex]

Do not do this. The game will fall apart. All trust in the DM will be gone. All trust in the player will be gone. The DM is not the players' enemy. Doing this makes the DM the players' enemy. There are board games that do this. It works there because who is the traitor is randomly chosen, the game doesn't take long to play, and both sides have equal chance to win. D&D is a social game. Player can only experience the world as the DM describes it. When you can't trust the DM there is no game. When you can't trust your fellow player there is no game.

[LibraryOgre]

Do not do this. The game will fall apart. All trust in the DM will be gone. All trust in the player will be gone. The DM is not the players' enemy. Doing this makes the DM the players' enemy. There are board games that do this. It works there because who is the traitor is randomly chosen, the game doesn't take long to play, and both sides have equal chance to win. D&D is a social game. Player can only experience the world as the DM describes it. When you can't trust the DM there is no game. When you can't trust your fellow player there is no game.

Then trust them. Trust them to be playing in the interest of everyone, instead of you trying to win, based on an idea of what is fair.

[Catullus64]

I've done it fairly recently, and it worked fine, mostly because the player character in question was a rather 'soft' mole. She wasn't purposefully planted in the party to undermine them and bring them harm; rather she was an agent of one of the major bad guys, sent to gather information on the location a magical artifact, who fell in with the party by circumstance before they ever came into conflict with said bad guy.

When the cards finally got laid on the table, characters were shocked and angry, but players were all pretty level-headed about it, because the character's transgressions had not manifested in problems in the moment-to-moment adventuring gameplay, and the character's camaraderie with them was genuine. Nobody felt that their time had been wasted or their trust as players violated (again, out-of-game; the characters were pretty sore about it). It then turned into a plot about the character trying to redeem themself by turning double agent and feeding false information back to the bad guy. The traitor player has some attention issues that make it hard for them to stay focused over long sessions, and the traitor plot was something we worked out to help keep them engaged.

[Eldan]

If I ever did this, I would put all the players in he same situation.

Either
1. Each one has a secret agenda and goal, all mutually incompatible

I did something like that, except it was a double bluff. I told every player they were secretly a traitor, except they all had the same secret treason goal, just given by different factions.

Specifically, they were all on a spaceship with an experimental new drive mechanism, going on an expensive cruise with a lot of celebrities on board to generate hype for the company that owned it, and they all had the secret mission to sabotage the journey, while having an entirely different official goal to investigate a murder on board.

[Boci]

Then trust them. Trust them to be playing in the interest of everyone, instead of you trying to win, based on an idea of what is fair.

Or don't trust them. It's fine if the whole group is on board, but there's use forcing the matter.

Sometimes when I DM with the right group, we play very dark themes that require a lot of trust from my players that I'll handle them correctly. If someone in the group isn't comfortable with this for whatever reason, I'm not going insist they trust me to handle it well, we'll just drop those themes. Everyone needs to be on board with this stuff, or it doesn't work.

[Jay R]

I did something like that, except it was a double bluff. I told every player they were secretly a traitor, except they all had the same secret treason goal, just given by different factions.

Oh, nice. That gives all the advantages of paranoia and secrecy, without some players having to lose because another player won.

I've done it, from both sides, and find it works fine, provided it doesn't become a crutch, and both the DM and the secret traitor are working for FUN, not to win.

Exactly. The problem with PvP, in any form, is that when the DM is running all the enemies, s/he's not trying to defeat the PCs, but to provide conflict and obstacles for them. By contrast, with PvP, or a traitor, or some such, the player on one side actively wants the other players to lose.

From my "Rules for Players" document:

8. The basic unit of D&D isn’t the PC; it’s the party. Fit in with the party. Support the party’s goals, and defend your allies.

a. Don’t betray the party; they know where you sleep.
b. You can have personal goals and secrets, but don’t let them get in the party’s way. [Yes, this also applies to a paladin.]
c. Yes, you decide what your character is. Decide to have one that makes the game better for everyone, not one that hurts the game for other players.

9. It’s all right to have secrets from the party. It’s not all right to have secrets that will hurt the party.

a. If your character’s goals would hurt the party, then your goals for the game will hurt your friends. Just don’t.

[MonochromeTiger]

Betrayal within the party can be done, but it needs to be done very carefully and you need to be sure everyone at the table can handle it.

Negatives are fairly obvious. First and most likely to come up is that it goes against some very basic assumptions of proper table etiquette, namely that the party act like a party and try to work together instead of just throwing each other to the hounds whenever it's convenient. That kind of behavior leads to plenty of horror stories and is a big reason why you can't say "evil player character" or "evil campaign" without somebody jumping in out of nowhere screaming "it's impossible without them killing the party or getting killed by the party." In some ways this actually gets worse for the "mole" player because by making them actively opposed to the rest of the team you've instantly turned every difficult encounter in the game into an opportunity for them to "win" by withdrawing all support and letting the rest of the party die.

You could, of course, make the possibility known ahead of time but then that just makes everyone suspicious and robs you of your apparently sought after "dramatic reveal" moment to try keeping people from feeling hurt over it. Paranoia and a few other games like Among Us have been brought up in the thread as an example of that, trading the shock of the reveal for tension and distrust as everyone has to question everyone else's every action. Thing is Among Us is actually a great example of how even knowing it's happening doesn't prevent problems when people get invested, there are people who will form actual grudges and lasting distrust over how well others fooled them in that game despite knowing it's a game where that's the entire point.

Knowing who you're trying it with is half of how you pull it off successfully. You need to be sure they aren't likely to take it personally and you need everybody involved, both the "traitor" and the rest of the party, to be fully willing to deal with the consequences in game and willing to talk through anything that comes from the situation out of game without taking it any further.

[Slipjig]

I think this usually works best in a one-shot, though it can also work if the traitor is revealed at the end of Session One of a new campaign (and then becomes an NPC antagonist if they survive the reveal), or during the last session of a campaign (because the story is ending, so the character won't be playable anyway). In any of those cases, I would talk to the players as soon as the session ends and make it VERY clear that you REQUESTED the traitor character.

I'm assuming we're not talking about a "your long-running character has been possessed/doppleganger-ed, and I want you to keep playing them until the other players figure it out". That's fine for a brief period, but I would encourage that player to exhibit some MAJOR signals that something is wrong (e.g. major personality shift, not knowing important details).

If you want a long-running mole, a couple of things to think about:

1) Give strong hints there is a traitor, so the reveal doesn't come out of nowhere. e.g. the villain's lair they raid is cleaned out before they get there, people who tipped them off turn up murdered, etc.

2) Include multiple NPCs who are plausible suspects. You can whittle the suspect list down over time, but if there's a situation where most of your suspects couldn't be responsible, take a pass on that opportunity for sabotage. Spies are valuable and hard to place, they shouldn't risk blowing their cover unless the payoff is HUGE. Don't risk their cover on minor stuff.

3) Work with the Traitor PC to determine their motivation, make it a believably strong one, and make sure the rest of the party knows about the motivation. It the BBEG has the PC's family, make sure he talks about how important his family is to him (and maybe rescuing them is supposedly the reason he's in the party). If he supports the BBEG's goals, have him float a trial balloon once in a while ("I know BBEG's the WORST... but he kind of has a point about X"). If it's personal ambition, have the PC grouse about how unfair his situation is ("As the Duke's second son, I'm almost certain to spend my life in service to my older brother, who is a fool.")

4) Make sure the player with the Mole understands that he is NOT to turn on the party early. If the DM has calibrated a fight to be tough, having a PC flip sides unexpectedly could easily end in a TPK.

5) Make sure the player understands that if he's outed early, his character will become an NPC (assuming he survives). This isn't punitive, it's just practical. Also, make sure that the Mole understands he ISNT "playing to win". The goal is for his character to enhance the story. Maybe present it as the player being a "Secret Assistant DM" as long as this is going on.

6) If the players figure it out early, let it happen. That just means you and the Mole did a good job laying the groundwork for the twist.

But you also need to know your players. Some players will eat this up, but as we've seen in this thread, there are definitely people who will NOT be happy with you or the player with the person who played the Mole.

[Flyfly]

It can be done, and other have already spoke well enough about the deets, but I think the big issue is that it just... really isn't all that fun in actuality?

Like, it maybe is fun for the DM (who knows) and the traitor (who knows), but for everyone else the experience can be described as [???].

See, if PCs know there is a traitor, the play usually turns into a slog. Every time everyone takes camp or even does anything everyone now pays attention to everything, game turns into a super slow mode, everyone explains how they protect their magic items from each other, etc. This might sound cool but just trust me, actually seeing playtime wasted on pointless paranoia instead of actually adventuring is unbearable.

And what if they manage to learn who the traitor is? In many games PCs have a ton of tools to learn something like that if they are suspicious, so it's definitely a possibility, can happen pretty fast. Then... they just kill 'em and move on with their adventuring, and player makes a new PC? This... also sounds very anticlimactic actually.

If they don't know... well, it would just come out of nowhere. Sure, it might be a climatic thing for the GM and the Traitor, but for everyone else it's just a inexplicable unfun plot twist.

Honestly, even for Traitor/GM, there would be a lot of one on one rolepalying, which is a very give-or-take experience as-is, and which would also take away playtime from everyone else.

My point is, there isn't much winning on this hill. You can, but should you really?

I think the only way to know is play less-immersively, get everyone on board and tell everyone who the traitor is right away, so everyone can enjoy shenanigans.

[Slipjig]

Oh, here's another tool for handling it: give the Mole an objective where the rest of the party being killed represents a FAILURE. The BBEG needs them alive for some reason.

Maybe one of them is the rightful heir of the relam the BBEG is trying to usurp, and if she dies the claim reverts to a powerful neighboring kingdom. Maybe he's already laid the groundwork for the party to take the fall for something, and it doesn't work if they are already dead by the time it happens. Maybe the mystic ritual for his ascension requires someone of a specific bloodline.

The Mole doesn't even need to know the reason is, all he needs to know is that he has strict orders to keep the party alive and on-task.

[Zanos]

Then trust them. Trust them to be playing in the interest of everyone, instead of you trying to win, based on an idea of what is fair.

Two things:

1. Some DM's don't deserve to be trusted. You shouldn't play with these people, but sometimes you are and it's better to steer them off the course of pure disaster when you can.
2. DMs that do deserve trust don't always make the best decisions. Just because someone is thinking about the health of their game and whether their players would enjoy something doesn't mean that their assumptions are always correct. Normally, a good DM would just ask his players, but the entire conceit here is that it's a secret, making that difficult. OP is here asking if it's a good idea, so I assume that he cares, so I'm going to tell him that 99% of players are going to hate this if you don't get their buy in.

Anyway, this is a horrendous idea to do secretly. The vast majority of D&D parties are formed by a group of ragtag weirdos who wouldn't trust each other normally, and some measure of OOC politeness is required so that 4+ adventurers can at least passingly trust each other enough to tackle lethal situations together. This idea abuses the goodwill players have extended OOC so that their characters can actually be included in the party. Just think about the typical adventuring party from an IC perspective, there are many, many characters that are too weird, too secretive, too seemingly useless, etc. etc. that a real person would look at them and say "I want this guy to watch my back." But you tolerate it, and their strange behavior, because the guy playing Obvious Dhamphir or Drow or Tiefling or whatever other often Evil character archetype is your fellow player and you want him to be able to play, and not just tell him you're not really interested in adventuring with his character.

This happened to me as a player twice. On the first occasion, I was playing a vampire, since I was the edgy one back then. I would be outdone by the traitors character introducing himself by walking out of a portal, wrapped completely in bandages, refusing to tell us anything about himself, and said he wanted to accompany us. I pointed out to the DM that this guy was kind of weird, but he was being played by a fellow player so I just implicitly trusted him and let him join up, as did all the other players. Anyway, the game ended because he stabbed us in the back during an important fight while we were low on resources, and the entire party was either killed or enslaved by an Evil god. What a great ending!

On the second occasion, I was playing dark sun as an archivist necromancer, and the traitor character in question was working for one of the Sorcerer Kings. I saw him talking to his contact in a brothel owned by a rival sorcerer king, and he grabs me and pulls me into a room and he and his associate start discussing whether or not to kill me and he tells me to make my case for why he shouldn't kill me. I don't say anything, because I've already instructed one of my undead creations over telepathy to hand a note to one of the guards of the brothel with what room I'm in and that there's trouble. The guards grab him and his associate, torture and mind control them until they admit their association, and then execute them. I manage to get out of the situation by lying a lot about who I am and what I was doing. The player who had been playing a character he quite liked for 9 months is pissed off, and he agrees to "stay" in the game by rerolling a character that is a complete mute and refuses to communicate with anyone in the party in any way out of spite.

Both times this happened to me, I obviously didn't enjoy it at all. The first literally killed the campaign and everyone was just confused, since we all just implicitly trusted the weird bandage man since he was a PC and PCs are your teammates, right? The second one shouldn't have surprised me because I knew the player was a toxic guy, but I liked the DM having played with him for quite awhile, and really expected him to do better than to set up the game so that could happen; it turned out it was the players idea to be a traitor, not the DMs. But "winning" under these conditions doesn't feel good either, I didn't feel like I had uncovered some nasty plot against the party, I just felt bad for getting the dudes character killed, even if it was completely his fault.

Look, I'm fine with a game of Vampire: The Masquerade, where every member of the coterie has motivations and loyalties that will put them at odds with other members of the coterie. That's fine, because it's what the game is about to some degree. Maybe you're playing a more observant and paranoid guy who is keeping an eye out for when someone's conflicting loyalties are going to compromise you own goals. Maybe you're playing a naive young vampire who gets taken advantage of. Both perfectly legitimate characters. The important thing is that both players knew what kind of game they were signing up for. If you're trying to introduce this into D&D secretly, the traitor and the "regular" party members are playing completely different games.

EDIT: I actually recall a third time this happened. One of the party members was kidnapped and replaced by an evil doppleganger. We never discovered the replacement, because while the DM expected my character to notice the transmutation auras, I didn't scan the party with detect magic for a few days because nothing strange had happened as far as I knew. Anyway, we were supposed to save the character and uncover the ruse, as the player kept playing the doppleganger, but we never did. Eventually the double attacked us during a fight, but we killed it and discovered the PC had died in the meantime. The player quit the game, although to be fair nobody really cared about the character or the player, since they basically only complained whenever they opened their mouth. Still not a great resolution.

[Kurald Galain]

EDIT: I actually recall a third time this happened. One of the party members was kidnapped and replaced by an evil doppleganger. We never discovered the replacement, because while the DM expected my character to notice the transmutation auras, I didn't scan the party with detect magic for a few days because nothing strange had happened as far as I knew. Anyway, we were supposed to save the character and uncover the ruse, as the player kept playing the doppleganger, but we never did.

I've had the "doppelganger plot" happen to me twice, in both cases trying to play my (long-term) character blatantly differently, and in neither case did the other players notice anything.

This is actually a better version of the "traitor player", as the expectation for the possessed player is that eventually the bad guy will reveal himself, be defeated by the rest of the party, and leave the possessed player with his original un-possessed character again.

The first time I've been possessed, that's precisely what happened. The second time, it turned out that (with me being the most tactical player at the table), my character plus buffs from being possessed was able to wipe the floor with the rest of the party combined, and the GM had to resort to a blatant deus ex machina to save the day. The end result is that the party lived and I got my non-possessed character back with a nice redemption arc...

...and this plot still wasn't particularly fun for anyone except for the GM and myself, so I'm going with Flyfly here and saying that (in most groups) this just isn't fun for anyone.

It can be done, and other have already spoke well enough about the deets, but I think the big issue is that it just... really isn't all that fun in actuality? ... Sure, it might be a climatic thing for the GM and the Traitor, but for everyone else it's just a inexplicable unfun plot twist.

Precisely.

I recall a third time where to almost happened to me as my PC was possessed by a demon, except I had a sentient magic sword that was able to counter-possess me, and I spent the next couple months possessed by my own sword until we could find a high-level cleric to fix the damn thing. Now this was actually fun for all involved.

[Cactus]

I believe there is a Battlestar Galactica game with traitor mechanics for cylon infiltrators. I don't know it in detail but some of my friends played and enjoyed it.

[Pex]

I've had the "doppelganger plot" happen to me twice, in both cases trying to play my (long-term) character blatantly differently, and in neither case did the other players notice anything.

This is actually a better version of the "traitor player", as the expectation for the possessed player is that eventually the bad guy will reveal himself, be defeated by the rest of the party, and leave the possessed player with his original un-possessed character again.

The first time I've been possessed, that's precisely what happened. The second time, it turned out that (with me being the most tactical player at the table), my character plus buffs from being possessed was able to wipe the floor with the rest of the party combined, and the GM had to resort to a blatant deus ex machina to save the day. The end result is that the party lived and I got my non-possessed character back with a nice redemption arc...

...and this plot still wasn't particularly fun for anyone except for the GM and myself, so I'm going with Flyfly here and saying that (in most groups) this just isn't fun for anyone.


Precisely.

I recall a third time where to almost happened to me as my PC was possessed by a demon, except I had a sentient magic sword that was able to counter-possess me, and I spent the next couple months possessed by my own sword until we could find a high-level cleric to fix the damn thing. Now this was actually fun for all involved.

It was done on me recently too. I literally quit the game session. I refuse to play player vs player. Being a doppelganger is not an excuse. That's DM deliberate interference. I could have handled it better, but when I cannot trust the DM or players there's no more game for me. Fortunately cooler heads prevailed. We talked it out. I didn't leave the game and am still playing. I was even willing to let it play out, but the DM redid the scenario so that the doppelgangers were all and only NPCs. It was supposed to be a lead in to the party is imprisoned by the BBEG story arc which we're playing now. It's a railroad but one I'm ok with in this instance. I am enjoying the arc. The hiccup was in the player betrayal set-up.

[KorvinStarmast]

Two things:

2. DMs that do deserve trust don't always make the best decisions.

True.

Spoiler: the doppelganger problem

Show

I actually recall a third time this happened. One of the party members was kidnapped and replaced by an evil doppleganger. We never discovered the replacement, because while the DM expected my character to notice the transmutation auras, I didn't scan the party with detect magic for a few days because nothing strange had happened as far as I knew. Anyway, we were supposed to save the character and uncover the ruse, as the player kept playing the doppleganger, but we never did. Eventually the double attacked us during a fight, but we killed it and discovered the PC had died in the meantime. The player quit the game, although to be fair nobody really cared about the character or the player, since they basically only complained whenever they opened their mouth. Still not a great resolution.

There need to be cues or clues that the other players/PCs can (maybe) pick up on to give them an inkling that something isn't quite right. Doing that can be tricky. it also helps if the player who is now playing their own doppelganger embraces it and figures out how to leave a few tells, subtly. That takes good acting.

We have had successes and failures with this particular monster in the past, and I have chosen as a DM to never do this in on-line play. It's hard enough in person.

It was done on me recently too. I literally quit the game session. I refuse to play player vs player. Being a doppelganger is not an excuse.

Or DM+{1}Player versus {other}Players.

[Slipjig]

Wow, those are some pretty awful setups, I can see why a lot of us have such a negative reaction to the idea. It seems like a common thread is that it's usually the player's idea, rather than something the GM initiates. We have a spreadsheet with a pretty extensive list of lines and veils we ask everybody to fill out before joining. I definitely wouldn't try this if anybody had checked the "No PvP" box.

I think the one reason you might do this is that players are always on the lookout for betrayal by NPCs. If you are looking to give somebody the genuine emotional shock of a betrayal, it has to be someone the players trust, and that's usually the other PCs.

But 100% there are plenty of tables where this would be a TERRIBLE idea.

[LibraryOgre]

There need to be cues or clues that the other players/PCs can (maybe) pick up on to give them an inkling that something isn't quite right. Doing that can be tricky. it also helps if the player who is now playing their own doppelganger embraces it and figures out how to leave a few tells, subtly. That takes good acting.

Play it like a body switch episode. You are not playing Bob, you are playing Sarah playing Bob.

[icefractal]

One reason it's tricky (and potentially a problem with the concept in most campaigns) is that for many groups the default assumption is OOC cooperation even if IC there'd be reason to be suspicious.

So Krog is acting unusual. First off, people might just assume that Bob (Krog's player) is underslept / distracted / etc and the unusual behavior shouldn't really be considered IC. Secondly, they might assume that this is the start of a Krog-oriented plot arc and they should play along with it rather than trying to prevent it.

In the latter case, I could see people getting quite annoyed, because it feels like their attempts to cooperate and make things easier for Bob and/or the GM were weaponized against them. Something similar happened in a game and did in fact piss me off:
> Setup is pretty basic, we get the obvious plot hook and nothing else of interest seems to be happening in town.
> Ok, obviously the GM doesn't have anything else prepared. That's fine, we'll bite the hook and do the adventure.
> Adventure is a double cross. Ok, we can work with that.
> GM OOC says we should have been more cautious about who we accept jobs from?!
> Are you ****ing serious?
> We took this job because it strongly appeared you had nothing else prepared. We suspended IC cautiousness to help you OOC, and you mock us for it?
If this were a GM in my group, there would have been words had. As it was a game at a con, I just stopped caring about the scenario and made a note not to play any game that guy ran in future.

So I guess IMO, there are two ways to do it right:
1) Make it clear from the start that PvP is on the table and the players shouldn't take everything at face value.
2) Have the "betrayal" be only IC, with people knowing it was coming OOC.