Speak Through Mobs

[comicmess]

So I'm working on building this little world to run a single group of friends through and I plan on making it feel like a tabletop RPG plus graphics. And combat.

The problem I have is I want the NPCs to react like they were real people, rather than have the players spit back one word that was in brackets to advance the conversation.

What this means is my quest trees cannot be long enough to support true interaction and so I was wondering if there was a reliable way for server admins or gms to control NPCs, from speaking through them to moving them reliably (and if so what is it).

Thanks!