Games with hidden traitors are some of my favourite games, I love the co-op, nature whcih gets every talking together combined with the tension of not knowing who to trust.
My top three games with this mechanic are #Dead of Winter: A Crossroads Game, #Battlestar Galactica: The Board Game and #Shadows Over Camelot. I thought I might run through how each of them utilises this mechanic and how they each enhance it:
Shadows over camelot
This was the first heavy hidden traitor I ever played (and lost). It is older but still a phenominal game. You each play a knight of the round table going off on quests to save the kingdom, completed quests/missions get you some white swords, failed quests get you black swords. Majority at the end of the game wins. Now this game helps the traitor out in two ways: First, every turn, before the do their actions, the active player has to chose one bad thing to do, all of them are awful and it is often unclear which is the worst one at any given time. This casts suspicion on everyone (especially when you chose to draw an evil card and it goes south fast) and helps them hide their villiany. The other thing is that the game prevents you from even making explicit claims about what cards you are holding. The cards are what are used to complete the quests (both numbered cards for most missions and very specific cards for certain uber-quests), this both prevents everyone from just comparing cards and working out a perfect plan and also allow the traitor to bluff about what cards they have, fake unfortunate miscommunications or bad guesses about what someone else needs without arousing too much suspicion as everyone is making those mistakes (just some more genuinely than others). All this mkaes it very hard to pinpoint and accuse the traitor (if there even is one!) and ramps up the tension. This is also a super hard game and I have almost never won when there is a traitor around the table.
This game has guarranteed traitors around the table but they are can be very tricksy to find. It also does a great job of capturing the slowly degrading situation of the fleet portrayed in the tv series. Each character recieves cards every turn of two or three out of five possible colours (depending on their character) there are ways to get other colours which can muddy the waters. Each turn some kind of crisis will occur, and between all the players you must contribute cards equal to the difficulty of the crisis. However, on each crisis, some colours will count positively while others will count against you. All the cards are handed in face down and players aren't obliged to contribute and shuffled so you can't tell who gave what (although you do know how many cards each player gave). As such, cylons are trying to either prove themselves as loyal by playing helpful cards or trying to sneak in harmful cards without realising suspicion. To help them, each crisis two random cards are added into the pile so you can never be entirely sure where certain cards came from. This always leads to brilliant moments as players try to work out who (if anyone) tried to sabotage the mission and raise suspicions.
This game also has mechanics that allow you to check to see if someone is a cylon, they are difficult to come by and only the person who plays the card gets to see and can lie about the result. However, the game throws a curve ball in that new character cards are handed out again halfway through the game. So someon who was once a human who you trusted may become a cyclon part way through. This does a great job of resowing doubt in everyone's minds. Which again is very on theme.
Dead of winter
Probably my favourite of the three although that may be just because I own it so have played it more. This game may or may not include a traitor, which always allows for some doubt in your mind when accusing someone. Each player (and the traitor) also have secret personal objectives which are usually fairly straightforwad and require hoarding of a particular type of supply or barricading the camp to a certain degree. These do a great job of making everyone suspicious as everyone will deviate from the 'ideal' actions at various points or secretly hold on to items that the team needs as you only win as a non-traitor if both the team wins and you complete your objective. As such accusations quickly start flying but it is hard to be sure. This gives plenty of cover for the traitor, as well as a good excuse if they are caught out in a lie 'it's for my personal objective, honest'.
The other great thing about this game is that you each have a little team of survivors you control who can absolutely die (quite easily in some cases) and so people act to protect their own characters at the expense of the team (or hoard all the best items for themselves because they are suspicious of who can be trusted with them). The corssroads cards also add some interesting choices for the traitor as they try to chose/convince the team of the option they think will harm the colony without damaging them too much.
Anyway, those are some thoughts on how traitor mechanics can be eleveated and done in interesting ways. Do you guys like hidden traitor games? Which is our favourite?