How about an RP in which a player has to come up with diplomatic solutions to obstacles. Things like fast talking, stealth, subterfuge, bluffing, trickery, and the like. If seduction is used, you'd have to be 18 or over and take it to PM. For my part, I'd put obstacles in the player's way for them to overcome.

Some example of this might include the following, with 1. being a direct way of handling a situation and 2. being the trickier one.

1. Fighting past some guards to recover a treasure.
2. Convincing the guards that you are one of them to get the treasure.

1. Killing a monster which is guarding a bridge.
2. Tricking the monster into leaving its post.

1. Defending a town which is under attack.
2. Running to get reinforcements for the town from a nearby fort.

1. Slaying a dragon to get its hoard
2. Fooling the dragon by making it think its hoard will be attacked by outsiders, leading to the dragon attacking the outsiders preemptively, while getting others to set a trap for the dragon when it attacks.

So you're roleplaying as the obstacle whereas us as the challenger?

Yes.

Would you like to do this via PM or have a proper thread?

A PM would be easier.