There's often a difference of degree, however. If my trouble is that "I cannot resist buying beautiful things" then it's not often going to dictate how a scene is going to go.
Well, actually...
If the GM is running it well, all compels are going to be more or less equal, on long average. So, like, "I cannot resist buying beautiful things" should manifest as something that
actually complicates the scene. Like, there's an art store that distracts you from being on watch, so the bad guys get past you unnoticed, or something
relevant to the drama at hand.
So, that leads into a question of what makes a good aspect - especially the Trouble aspect, which is mostly what we seem to have been talking about, even though you can be compelled on any Aspect, or Consequences you took from stress.
It might reduce my resources (which does affect the team, but not by much) or it might get me a sticky aspect like "owes money to XYZ" which could drive a later group scene, but likely only when a GM desires it.
Fate doesn't track resources in a detailed way - so if it manifests, it will be in a moment in which the lack is a
real problem. Like, you were supposed to have that cash to pay off the drug pusher to get a kid out from being his mule, or something really important, and in that moment the suitcase of cash isn't there...
But if my aspect is "picks a fight with people who annoy them" it is very natural for it to turn a scene where the party is happily negotiating a deal into a combat scene.
Yes, it can. But, then,
THAT'S THE POINT. That is the system working as designed. Compels are
supposed to make things go a little sideways.
As a GM, if the player says "because I pick a fight with people who annoy me, it makes sense that I would punch this guy" I would find it hard to say that doesn't qualify as a self-compel.
So, in Fate the rule is not "The GM will accept anything that is a valid self-compel". The GM gets to choose, and ask themselves, "Will this make the game better, or just a pain in the butt?" If the latter, the GM can and should say "No."
In this case, for example, if the session has been going the player's way, everting's gone smoothly, no hitches, that's a great time for an awkward unwanted fight to break out, and turn that delicate negotiation into a bar brawl in which the party now has to try to get the McGuffin out of the room in the chaos. That sounds great!
If the party has already had three fights, and everyone's got a lot of stress and Consequences already... maybe not.
Yup, that was the way it was played. But the text "You are hunted everywhere, or the crime is severe with active bounty hunters tracking your trail across the Weird West." makes it pretty clear it's going to happen regularly. And since we hung around as a group, most times the bounty hunters turned up, it was an all-hands gunfight.
Yeah, that's a GM problem. It is the GM's job to work such stuff in in a way that's
interesting , not just a slugfest every session or two. That's boring.
Overall, I do like "GM bargain rewards" as a general mechanism, but they do have noticeable failure modes.
Sure. But is there any mechanic that doesn't have a failure mode or two lurking in the background?
One is the power-gaming one, which I mostly see when narrative systems are bolted on to traditional games.
shrug. You don't get so much out of a Fate point that it becomes a real power move. And, really, I don't expect backing up a truck of Fate points to hit a "win" button would be exciting for power-gamers.
The other is the player who uses a flaw effectively to force a narrative change on the group
I'm not sure this is a distinct flaw of the mechanics. Narratives are being changed by everyone, all the time. Every time a player makes a choice, the narrative changes.
Like, a disruptive player can make a fight break out without self-compelling, if they want a fight to break out. He doesn't need a flaw saying that he can do that.
No mechanic will save you from folks who don't want to play well with the rest of the table. That's not a mechanical issue.