[Intrepid Homoludens]

Well, I got the idea because, as I played KoTOR and developed an attachment to certain characters through optional side quests and dialogue branches, I thought, Why in hell has the adventure game genre been lacking this kind of depth and complexity all these freaking years?! But that instead of combat, you gain experience points for your characters through solving puzzles and negotiating complex dialogue options?

For example, let's take that hypothetical game idea I had where a vacationing group of your characters is trapped in a huge sinking cruise ship, and the main story consists of trying to escape. Each one represents a character class - say, policeman (soldier/scout), scientist (mage/demolitions), con artist (rogue/thief), computer geek (lockpicking/hacking), etc. The ship would be a veritable labyrinth of potential environmental traps, inaccessible rooms, and mechanical and electronic puzzles to maneuver. There would be optional puzzles here and there, and they can only be solved by specific members of your party. With each puzzle solved you'd gain experience points to spend on your party members' skills upgrades. The main 'quests' would further the central story, but the optional quests would gain you insight into each character's personal past, or even smaller stories pertaining to the history of a person/place/thing.

Think about it.