Bluffing the Truth

[Doughnut Master]

So it occurs to me that in D&D world there is no such thing as a false confession because the sense motive doesn't apply to innocent people. So I was wondering if anyone had developed any system for more nuanced relationships to the truth.

For instance

1. Telling the truth but being bad at it. After all, lots of people get into trouble when they're telling the truth simply because they seem suspicious.

2. Telling the truth and intentionally making the other person think that you're lying.
Guard: "Why are you here?"
Assassin: "To kill the king."
Guard: "Hah. That's rich. Go on through."
(Yes. it's a ridiculous situation.)

Has anyone found a reasonable way of running these sorts of interactions?

[Saph]

How I run it:

• Diplomacy is the "tell the truth believably" skill.

• Bluff is the universal "deception" skill, no matter how you choose to do it - you can fluff it as telling the truth in a ridiculous way.

• Sense Motive is the "tell if someone's lying" skill. The player gets to roll it. If he gets decently high (15, 20, 25, the higher the more info) he'll be told that the NPC seems genuine. Of course, if said NPC happened to be lying and happened to score higher on his Bluff roll, the player will also be told that the NPC seems genuine . . .