My new area of research will be looking into making a game which implements dialogue as an actual gameplay mechanic.
Dialogue is often overlooked as a part of gameplay. Either entirely scripted, or with just limited choices based on numbers. In reality though, the act of communication can be just as exciting as a fight. Thinking about it, many of the terms we associate with the act of speaking are also used for duelling.
If somebody deflects a statement with a pithy phrase of their own, or a retort, it's often called a 'riposte', and if hit by a clever riposte, somebody may say 'touché!' a fencing term implying they have scored a touch.
In a courtroom battle, there is a 'defence', even though there is no physical fighting. Words can be inflammatory, wounding, harsh, and a strong negative reaction may be called a 'backlash'.
In Monkey Island 2 (I think it was 2) they took this literally and made a part of the game in which the player fought a pirate sword battle using insults penned by the authour of the novel 'Ender's Game'. It was a very funny and clever set piece, perfect for a pirate game with little physical violence like Monkey Island.
In the Pen and Paper RPG 'Exhalted', the dialogue rules are written like the combat rules. Dice are rolled for the effectiveness of insults, persuasion and intimidation, against the defence roll of the enemy.
Dialogue has a lot in common with fighting. It is about judging your opponent's condition, balance and strengths, picking your timing and trying not to leave yourself open. Sometimes brute force (shouting somebody down) works well, but often subtle persuasion can achieve just as much.
Some ground rules for inventing my mechanic:
1. No 'statistics', or certainly not ones that the player needs to know. Everything on the player's end should be free of numerical values. If a person is shy, they will be represented as such by their actions and dialogue, not by a floating number next to them saying 'shyness: 33'
2. Nothing random. Or not if I can help it. Everything in the mechanic should be based on the player's logic and deductions. I want the mechanic to be like chess, not snakes and ladders.
3. Keep the scenario simple. Interviewing Witnesses maybe? or Criminals? Trying to win an argument or debate? Seal a deal? Argue a court case?