Continuing this project. This method would also work for intelligent swords and other sentient items in that other fantasy role playing game. Might also be fun to play with in Call of Cthulhu/Delta Green or Mothership.
I've mentioned rival personalities as potential complications for a couple different archetypes now, and I think it's pretty obvious what that means in the context of comics (especially when there's a movie about Venom and a show about Legion and I'm pretty sure Ghost Rider is on that Agents of Shield show). I haven't really explained how to adjudicate it fairly though.
The most obvious option is to make players roll on a random table of traits a few times. That sounds kinda boring to make and not even really all that helpful in terms of how the rival personality impacts the game.
No one in my current playtest has to deal with a rival personality at this point (but there are experimental pharmaceuticals in play so who knows), but I've got an idea of what to try if/when that changes: Schrodinger's personality, with individual decisions decided by luck checks and precedent.
The PC is going to need to keep a list of what actions are and are not cool from the rival personality's perspective, presumably on the back of the character sheet or something. If the pc has multiple rival personalities, the player keeps a separate list for each one and which one is dominant is randomly determined whenever the issue comes up. The player can give them names if they want to, but make sure they realize that they don't know at this point how this personality is gonna turn out.
The first time the PC makes a moral decision of any kind, they need to make a luck check (and spend a luck point because it's Troika) to see if their rival personality is okay with it. They need to repeat the procedure again anytime they make a moral decision that isn't already covered by precedent (so if it works like I want it to, these checks become necessary less often as the campaign continues and more situations are covered by precedent). It's often in the PC's interest to ask the referee for a luck check if there is a shade of difference between the current decision and the one that set the precedent.
EXAMPLE: Spiderman's and then Venom's symbiote was initially defined by its bloodlust. Then, in the 90s, when faced with the choice to victimize or protect the innocent homeless people living under San Francisco, it and Eddie Brock unanimously decided to act as the community's guardian.
If your rival personality opposes something that you really really wanna do, you can attempt to make a raw skill check (that is, roll under just your skill stat, no powers or specialties apply). If you succeed, you manage to overpower your rival personality for now. If you critically fail (double 6s on 2d6), your rival personality takes over for 1d6x10 minutes. If, during this time, it is faced with a moral decision that isn't covered by precedent, the PC gets to try to make their own decision on what to do, making a luck check as usual. If the PC's decision is opposed by the rival personality, the rival personality does whatever the PC didn't want it to and a new precedent is set as normal. If the PC rolls a critical success on this luck check (snake eyes), they not only set a precedent that agrees with their stated desire, they also reassert control.
I guess this makes reverse psychology a possible metagaming tactic. For now I'll say that if you try that and you succeed on a luck check you were counting on failing, you have to go through with your stated decision.
I'm a little concerned about the randomness creating personalities that make even less sense than real people, but using precedent by default should keep that sort of contradiction at least somewhat in check. I'll find out when it starts coming up in-game.
