I have mentioned repeatedly my model of what a game is: Repeating units, like combat, held together by content (cut-scenes, quest text). So I was very interested when via Raph Koster's website I found this GDC talk by Matthias Worch which explains games with a very similar model: Bits of dialogue in which the player interacts with the computer and bits of monologue in which the computer (or rather the dev who programmed it) talks alone. The video is nearly 50 minutes long, but well worth watching if you are interested in the theory of games.

Once you've understood Worch's model, it becomes very clear why we can get into heated discussions about games like Mass Effect 3, where I was saying that the dialogue parts of the game were lacking, but others praised the game for its monologue parts. Or where I accepted the ending as being a monologue, and thus an expression of the authorship of whoever wrote that ending, and others disagreed with that expression, or would have liked a more dialogue-like structure allowing them to influence the ending more.

Ultimately it all comes down to the question of what percentage of monologue you want in your games. Do you want a Dragon's Lair like game which is mostly monologue? Or a game like Civilization which is mostly dialogue? Or something in between like the modern "action adventures" which have monologue cut-scenes between dialogue gameplay sequences?

Where I very much agree with Matthias Worch is when he remarks that the new PS4 will have a "Share" button on the controller, but people will generally want to share their great dialogue moments of the game, and not the great monologue moments which are the same for everybody. Games which are heavy on monologue also suffer from poor replayability, although that is probably a concept that is outdated anyway, and we are getting to a state where the big triple-A games are meant to be played only once, at least in single-player mode, just like watching a movie.