Plentiful only because there are 7.6 billion people. The number of people who mouth off in situations where they will die if they do is a vanishingly small percentage, even if you can find many instances due to sheer numbers.
So what? It happens often enough that it's possible.
It should be my choice whether my PC engages in suicidal behavior.
Did the trait say "Mouths off to authority" or did it say "Mouths off to authority unless there's actually some risk involved, in which case he shuts right up"? I mean, maybe the concept of the character isn't this rebellious dissident that I was imagining, but is instead a blowhard?
I mean.....the player opted to take that trait. That's an invitation for challenge. Allowing that to not matter at all seems pretty weak, honestly.
It's like an argument for how D&D doesn't require characterization to matter at all.
A mechanic doesn't allow you to "discover" it, though. It's just a roll of the die or whatever. No real discovery involved. However, as the player who actually knows the character decides whether he would or not, therein lies true discovery. I might just mouth off anyway if with my superior knowledge of the character, I decide that's what he would do. Or maybe I decide that the threat of death is one of the few things that will result in him keeping silent. Either way I've discovered something about the character. I didn't know it before the situation, and now I do know it.
Yes, rolling to find out.....that's discovery. I didn't know how it would go.....I know the character has issues with authority figures, but how deep are those issues? How important is it to him to challenge authority? Will he risk his life to do it? How much does this matter to the character?
If you've already decided the answers to those questions, then you aren't discovering.
I think you're selling players short. If the player is truly interested in discovering things about their character, they will make these hard decisions and often at the detriment of their PC. If they aren't interesting in discovering those things, why force it on them via a mechanic?
No, I don't think I am. I think any player who would have their PC mouth off to the emperor would be just as open to the idea of having to make a saving throw style roll to see if he does it or not. Because that player is playing the character with integrity.
They are risking their character's well being......or their conception of the character. They're not letting themselves off the hook.
So, to go to your example of the emperor and the mouths off to authority trait.....would your decision to have your character not mouth off to authority make you consider changing the trait? Did it in any way alter your perception of your character going forward? Or did he remain as the guy who mouths off to authority?