Most videogames follow Elvis's dictum to the extreme: "A little less conversation, a little more action." With the notable exception of Bioware's games and their branching-dialogue brethren, the player's ability to relate to other characters in the game is limited to the weapon he's carrying. Talk may be cheap, but conversations are hard.
Why? The first problem is content creation. Even assuming you take the Bioware style of branching dialogue trees as a given, it's a lot of time and work to write and script all of those interactions.
A second problem is that even after all this time, we haven't found anything better than what Bioware has done. Earlier approaches, such as the full-text conversations of Infocom/Eliza games or the hot/cold mood responses of the first X-Files videogame, haven't really caught on.
A third problem is that many players don't care. They want to skip through Bioware's dialogue trees as quickly as possible and "get on with the game." They don't really see all that talking as gameplay and dialogue fatigue is a common complaint about this approach.
So it's time to throw all that out and reconsider: what do we want to accomplish with conversations in games, how can we make them more interesting to more players, and is there an approach that would improve on what Bioware has done?
Why Talk in Games?
For games that include some kind of interactive conversations, there are generally two purposes: to express your character and to present the story. It's these purposes that have led us to the kinds of good/evil responses and expository dialogue that characterize the Bioware approach.
Games are about solving problems: how to fit those Tetris blocks together, how to take out a Covenant squad in Halo without exhausting your energy shield, how to manipulate time ingeniously in Braid. Our toolkit of player actions is informed by those problems. In Tetris we have basic movement controls to guide each block. In Halo we have a large number of buttons and joysticks to give us tactical breadth. In Braid we have a joystick, a jump button, and a succession of time-control abilities.
Even in Bioware games, conversations are represented by just two controls: a button to initiate a conversation (which usually also opens doors and interacts with objects such as switches) and the ability to select one conversational response from a list provided by the game. Moreover, the player's ability to use that interaction button is greatly restricted. You can rarely interact in combat, for example, and typically a given character's conversation is limited to quests. Once that character's quests are complete, they have nothing more to say.
In short, there is no arbitrary ability to use conversation as a universal part of the player's toolkit for playing a game. Talking is never on par with shooting. That's a glaring omission in our player toolkit and it's time we fixed it.
I've got one example. A decade ago, Sierra released an innovative PC squad shooter called SWAT 3: Close Quarters Battle. (Its big innovation was that it did realtime squad command very, very well; Rainbow Six - then circa Rogue Spear - hadn't made that leap yet.) In addition to the now-usual tactical shooter controls, SWAT 3 added something else: a Verbal Command button. When you pushed it, your character would bark out one of several contextual phrases including "Drop your weapon!", "Hands in the air!", "Get down on the ground!" and so on. You could hit this button whenever and as frequently as you wanted.