I know that the conversation mechanics in DX:HR(yes, that's how I'm abbreviating it from now on) got a passing mention back in my broad analysis of the game but I never really took the time to give the them a more focused and in depth analysis. I want to look at the large number of things this game does right in this area. These are things that I think we should be emulating and learning from. I'm also going to turn a critical eye on the game to see if we can't also scrounge up some places they may have been improved.
The inevitable first thing a player will notice is how the conversation options are summarized versus what your character ends up saying. This game gives you a single word description of the general feeling or idea of the choice along with a well chosen snippet of the line corresponding to said choice. I think there is only one time this game actually summarizes what you will say. I remember it very clearly, mostly because it came as a surprise. Even then it was a good summary that was clearly indicative of what you were about to communicate if you chose that option. This is one huge advantage of doing things this way. You can show off your well written and well acted dialogue without the player first reading the lines, and at the same time you make sure the player knows exactly what their character is about to say.
Okay, so this game does a phenomenal job dealing with the issues of summarizing your dialogue options, but what about dealing with ethical dilemma's? How does this game handle that? I'll tell you what it doesn't do, it doesn't try to measure your choices based on some frippery binary moral system. BioWare, I am giving the glare of death to someone in your general direction. In all fairness, BioWare won some redemption by having a general "reputation bar" instead of a moral mini-game in Mass Effect 3, but that is not the point.
What about DX:HR? Turns out, the game doesn't really do much to invite you into the moral discussions in the game unless you're trying to manipulate someone who has a particular point of view. You just sit and watch while every other character in the game explains their life philosophy and their thoughts on the subject of trans-humanism. You're given a few opportunities to express your personal opinions, but it is really only a very few. This is one of the shortcomings of the game in my opinion. It's not a problem with the mechanics used to allow player choice and discussion, it's the content that they were filled with that lacked a real opportunity for you to openly discuss the subjects the game was written to tackle.
It's not all rain and lightning though, there are bits of sunshine and roses within this game's handling of the dialogue trees. A very big positive thing here is that the game will allow you to approach different attempts to persuade people in different ways without bringing the ethics of treating people that way into it. I mean, come on, you're trying to manipulate people anyway. Instead, different people respond best to different approaches. Some people need you to pressure them, some people need a pep talk, some people need something else. They are all different.
It's kind of hard to talk about the choice involved in moral dilemmas when we haven't discussed the way the player's choices effect the plot. Actually, the way the player's choices don't effect the plot would be a better way of putting it. You can have influence on a few of the non-essential story characters, but you really don't effect the grand scheme of things until the ending, and let's be honest, the ending was really pretty awful. It completely failed to redeem this element of the game. Choosing sides in an ethical debate can't have any effect on the story or anything, so why would the game let you do it in the first place? Your choices are more about roleplaying and how you want to play the game and deal with certain situations than they are about effecting the plot and sorting out moral questions, and that's okay. Mostly.
Reasonable post length is running out, so I've just got one more thing to mention. This game allowed you to eventually use augmentations that helped you out in conversations where you were trying to persuade people. It digs up a psych profile on the character you're talking to and explains what the most effective strategy would be to persuade them. Then it reads involuntary body language like heart rate and such to help you know when you're getting the edge. It even goes a step further and in certain situations allows you to spam them with pheromones to help you force your way. It is a beautiful system because it doesn't just give you a bunch of story hogwash about being an augmented person, you get to experience the differences first hand. It also brings more ethical questions about human augmentation to the table, which is very important. Whenever game mechanics are part of the story and message of a game, you know that it was crafted by a good designer.
So in conclusion, the choice and dialogue mechanics in DX:HR are top notch. Maybe the story could have been written to take advantage of them and allow a more dynamic plot, but you can tell how hard it was to get this game out the door as it was. Adding even more plot and story would have been suicide. There is great handiwork in the crafting of these systems, and I hope we take something more away from this than a new appreciation for them. Of course, I don't think anyone would mind you taking away more appreciation for these systems. ;)