I’ve run six sessions of my cult game, and there is a definite sense of mounting danger. Not only because the crew is drawing the increasing ire of other factions (though they are) but also because the crew may be, to put it bluntly, a doomsday cult. Their patron deity, it turns out, is one nasty critter.
My approach with this game has been to avoid saying no, to play to see what happens, and to force the players to be proactive. That’s worked out well enough so far. And if things progress to the point where, in the worst case scenario, the crew wants to serve the world up to their deity on a platter, I won’t make it impossible for them to succeed.
My fear, rather, is that the crew won’t be united in whatever course of action they decide on. We’re reaching the point where party members are sorting themselves into opposing factions vis-a-vis attitudes toward the evil entity residing in their attic. Some have become its faithful servants, and others are, shall we say, concerned about their patron’s appetite. And if these disagreements escalate into conflict, we could enter a PC-vs-PC situation, which could break the game by eliminating the rationale for why these scoundrels work together, and, worse, may result in hurt feelings among the players.
Things haven’t reached this point yet (and possibly never will!) but I still want to plan ahead and be prepared so that, if things get there, we can resolve matters in a functional and considerate manner.
So, please let me know if you have any advice.
PC vs. PC conflict isn’t “broken” play, necessarily. (In fact, I think it can be incredibly fruitful, drama-wise, as long as everyone is on the same page.) Player vs. player conflict will almost certainly be an issue, though. So: have a conversation, out of character, about the game. Say: “Hey y’all! Seems like the crew might split into opposed groups sometime soon. Are we cool with that?”
If the group is cool with the story progressing in that direction, than you’ll handle it using the PvP guidelines in the book, which boil down to “agree on a method of resolution, then carry it out.” Note that the agreed-upon resolution doesn’t need to be mechanical–a player might volunteer their PC to be killed in some suitably dramatic fashion by another PC, while trying to stop a world-ending ritual. Neat! That happens.
If the group isn’t cool with the story progressing towards intra-crew conflict, then you all need to talk about ways to resolve things so that the crew stays together. Any option that makes the group happy, and fits the fiction at-hand, is a good option.
For example: in my first Blades campaign, the crew grew increasingly violent and erratic. This was good fun for all, but one player felt their character–an Iruvian doctor–wouldn’t put up with such needless bloodshed. We arranged for an “exit episode” for that character, where they tried to (and ultimately succeeded in) escaping “the life” and sailing out of Doskvol for greener(?) pastures. The player didn’t feel like they’d “lost”–just the opposite, in fact. Though their character no longer fit with the direction of the campaign, they still got a satisfying (if not rosy) ending for the PC, and came back the following week with a more suitably aggressive character.
Talk it out, then RP it out
I’ve had players make new characters when old ones seem out of place. It’s no biggie as long as you talk about it. Bringing it up from the angle of “we as a group seem to be pulling in different directions” is better than “Bob your character is blocking the action”.
In your case you could even make a whole new crew of Vigilanties finding out about and trying to stop the old crew if the players start having second thoughs.