That's even worse. You're starting a failed roll could result in no combat but a successful roll must end in combat. That's the exact opposite of how things should be. Once again, I'm fine with there being situations that players can't talk their way out of. I am fine with Kasia finding a marauder who just feels like marauding no matter what she says in that lonely barn. That's not the problem. The problem is that a successful use of a skill resulting in a worse (or at best same) outcome as a failed use.The success and the failure doesn't have the same outcome. If the player succeeded with the persuasion attempt (assuming there that the GM have accepted the player's description of the skill roll), the enemy inside the barn either have to accept that or attack. If the players skill roll fails, he can do whatever he wants to inside that barn. Sure he can attack, but he can use any action he wants, even nothing if he wants to
I'm just saying the same thing over and over. I understand that some people can't be persuaded. That's not the problem. I concede that the option to ignore persuasion needs to be there. I just think there needs to be some kind of mechanical benefit for successful actions, especially if the successful action can be totally negated by player or Referee Fiat. A one step penalty on the followup attack or a bonus free action to the Persuader seem the most straightforward. Anything else would be too laborious or advantageous.