Some groups are more moderate, maybe they can’t simply roll to bluff, but if you give me the gist of HOW you’re going to go about it, perhaps what your end goal to convince them is, I’ll modify some DC, making the roll and the lie thusly feel more involved.

I’m a big fan of the middleground, dice rolling with strong participation from the players, allowing them to have some degree of personal control without having to be some magnificent +14 liar.

Alright. That’s how you convince someone to do something through lying. Now how do you resolve trying to convince them of the truth? This is one of the thing I most often find lacking with GMs. Convincing someone of a lie requires you to play out lying, and roll, and re-enforce the lie… but NPCs seem to have some sort of Objective Truth Radar that changes the whole dynamic when the implausible story you’re trying to sell has the tangential benefit of having actually happened.