|The Thing, 1982|
The Ringer: Brief the players for the scenario, then hand out pre-gens; one of the pre-gens contradicts the briefing however and informs the player that their character is just a façade, since they are really playing the monster. The ringer is created in the same way as any other PC, but with an agenda that includes the death and/or torment of the others. Make sure you give the ringer to a player with a good poker face who is comfortable with pro-active role-playing; with this technique, I have seen three different players take on the same ringer in three very different ways.
- Patient: Waited for players to put their characters in jeopardy and took advantage of the situation; none of the players knew anything was up until the last half-hour of the game.
- Subtle: Made use of the ringer’s façade to isolate other characters one by one and put pressure on them, so they turned on each other.
- Monstrous: Immediately started isolating characters and endangering them; everyone knew something was up, but as it wasn't what they expected, they largely ignored it.
The hard part about this technique when GMing is not accidentally giving the game away; keep a briefing sheet in front of you with all the PCs agendas on it, including any false agenda’s pursued by the ringer, as well as their true agenda. Refer to your briefing frequently in regards to all the PCs, even if you don’t have to, and avoid giving the ringer any special attention beyond the support needed to threaten the other PCs.
The Traitor: Brief the players on the scenario or ask them to collaborate in creating one, but also ask one of the players to take on the role of the monster! All players can collaborate on deciding the traitor player’s agenda and suggest suitable attributes & specialisations, but the traitor is a regular PC during play, whose agenda is the major threat facing the other PCs. This can be played as above, with the players keeping their out-of-character knowledge from affecting their character’s actions, or the nature of the traitor can be known from the start, making it a game of cat & mouse for most of the session.
The monster PC in these cases usually has a strong home ground advantage and can freely narrate whatever locations or environmental conditions best suit their ploys; as GM, I let that PC frame their own scenes more often and don’t interfere in them too much, but add pressure to any scenes they are absent from to keep the other players on their toes. If the human PCs all put aside their differences and co-operate, they can probably overwhelm the monster PC pretty quickly, so I keep feeding them reasons not to trust each other and encourage them to ignore the immediate threat in pursuit of their own agendas.
In addition to the above, here are two gimmicks you can try; you can also use these to turn a GM-as-monster game into a player-as-monster game half-way through, but it would only be fair to warn players of the potential for this to happen.
Possessors: Ghosts, parasites and evil psychics can use a PC to carry out their bidding; prepare a set of index cards, writing on one a potted monster PC description, focussing on their agenda. At an appropriate point in the game (e.g. at the very start of the game or during a séance) hand out one card to each player; whoever gets dealt the monster is now playing that agenda. Any player can engage any other player in a conflict to swap cards; if they win the conflict, they swap cards with the loser and take one Survival point from them, adding it to their own Survival points. That should give plenty of incentive for everyone to do so, which of course throws suspicion on both players involved in a swap. It also present the players with the challenge of pinning the monster down in one body for long enough to kill it.
Infectors: Zombies, vampires and sentient diseases can all convert any number of humans into fellow monsters; using a variation of the above gimmick, players retain the monster’s agenda even after passing the card to another player. Depending on the monster type, the conflict required to infect another PC may require violence or physical intimacy; players should retain the option of still pursuing the regular agendas of their PC, but as their Survival points diminish, the monster should come more to the fore. The endgame here is all about defeating an ever growing army of monsters before they overwhelm the remaining humans... or before the humans join them.