With a Duel of Wits, you are opting in. You are staking that control over your character's autonomy to have control over the setting. It's a clear-eyed decision you are making. Want to convince the border guard to let you pass then you leave yourself vulnerable to being convinced to leave the way you came. You are staking autonomy for impact.
It's a choice that has an impact and consequences. This is the beating heart of agency from my perspective. You have an awareness of what success means, what failure means and go in clear eyed.
Are you allowed to have a "duel of wits" without actually having a Duel of Wits? Some of the things
@pemerton has said, and some of the things I've seen online, suggest that no. You
have to roll the dice.
So, are two PCs allowed to RP out a conflict without having to roll the dice? What about a PC and an NPC?
What happens if PC 1 says something that actually is convincing to PC 2 or to whoever is running the NPC, but PC 1 also lost the die roll? Can PC 2/the NPC ignore the roll and accept PC 1's argument?
Also, question:
@Old Fezziwig said that losing a Duel of Wits doesn't alter your thinking. Here you're saying that you can be convinced to leave the way you come. How does that work? In D&D, the PCs would roll a Charisma skill against either a target number or as a contested check. If the PCs didn't roll high enough and the border guard stayed firm, the PCs would then have a
choice: they could leave the way they came, they could wait for another guard and try again, they could try to sneak past the guard or find another way to get over the border, they could kill the guard, and so on.
So in a BW Duel of Wits, I'm assuming that
my side is "let me pass" and the
guard's side is "go back the way you came." If I lose the Duel of Wits, can I choose to wait for another guard and try again, try to sneak past the guard, or kill the guard?