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June 20, 2008

Conversations with NPCs

As Corvus Elrod likes to say, compelling stories arise primarily from the relationships between characters. Although these relationships can be generated or expressed in different ways, I think it's fair to say that conversation is probably the most obvious and frequently used method in games. Yet it's interesting to note that conversation systems in games are fairly rudimentary and, in many cases, pretty unsatisfying.

There are many reasons for that, of course; human conversation can be horrifically complicated to deconstruct, and dynamically generating realistic and meaningful conversation with computer-controlled characters is still years away, especially when you factor audio into the equation. As a result, most conversation systems in games are simplistic representations that often follow tight scripts and leave little room for exploration, which is probably fine with most developers; it's difficult and time-consuming to create sophisticated interactive conversation, particularly without forcing players to use text-based input, and most text entry in mainstream games was abandoned some time ago. In the end, conversation is typically an insignificant component of gameplay, demanding barely more thought from players than a cutscene might.

I don't have nearly the range of experience with games that many other people have, but I would venture to say that the conversation systems in most graphical, mainstream games fall under one of two general classes:

1. Click to speak. The simplest system, where you just click on an NPC or hit a single key to trigger conversation. The player typically has no control over the topic of conversation or what the player character says, generally or specifically.

2. Multiple choice dialog trees. Players select from a limited list of speech options, which helps direct the conversation to some extent.

I'm sure there are mainstream games with variations on these that I've missed or forgotten, but they are less common. Nevertheless, I have yet to see a conversation system in a graphical, mainstream game that is particularly satisfying. Most games that use #1 generally are just using conversation as a means of advancing a storyline, without really incorporating conversation into gameplay in any significant way. Systems related to #2 do at least involve some thoughtful input on the part of the player, and because the choices presented are often specific player quotations, the resulting conversation can seem much more natural while also providing some degree of characterization for the player character. On the other hand, this type of system also encourages a "lawnmower" approach of trying all options, even if it requires re-initiating the conversation or using the save/restore approaches. There is thus little consequence to making those choices, especially if the different conversation branches just lead to the same end point anyway, as is often the case.

It's probably clear to readers here that I think interactive fiction has a leg up on other game genres in many areas, and conversation is one of those areas. But why is that? Is it because the medium has more conversation tools at its disposal? Is it because text-based input (and output) allows a greater range of conversation possibilities?

I don't necessarily think so.

A while back Emily Short created what is essentially the seminal piece on conversation systems in IF, and there's little reason to rehash what she so comprehensively covered. For those not as familiar with IF or her essay, I'll just summarize the most common IF conversation systems, which mirror those mentioned above in graphical games. The three most common are:

1. TALK. Players just type TALK TO to initiate conversation with the character, which generally results in a single back-and-forth exchange with the NPC (though sometimes more, and sometimes less). Not unlike system #1 above for graphical games, where the player just clicks on an NPC to trigger conversation without any say in what is discussed.

2. Topic-based conversation. The most common form is the ASK/TELL system, where players type ASK ABOUT , or TELL ABOUT . Here, players can direct the conversation by specifying which topic to discuss. In many iterations, players are not prompted with specific topics to choose from, which forces them to think about which topics might be fertile to discuss. Alternatively, some games use a variation on this approach, where conversation topics are highlighted in the text, and players need only type the topic itself to trigger conversation on that topic. That said, often the topics used are too broad; players may intend to ask about a specific aspect of a topic, but are compelled to rely on whatever was programmed by the author. Another issue is that NPCs often end up feeling more like information booths than living individuals, dispensing conversation like a vending machine without much of a two-way dialogue.

3. Multiple choice dialog trees. Same as mentioned earlier. Unlike with the ASK/TELL and TALK systems, players have a pretty good idea what specifically they will be saying or asking with the NPC, rather than generally. Particularly in a text game, this can provide a better degree of characterization. On the other hand, all potential choices are patent, leaving little challenge for the player, particularly if the conversation branches all lead eventually to the same end point. Also, as mentioned above, the UNDO or SAVE/RESTORE commands encourage the lawnmower approach, which can lessen player involvement and remove much of any challenge that is present.

These basic systems are not all that fundamentally different than those used in most mainstream graphical games, and within the IF realm they have their advantages and disadvantages. To me, though, there are three main reasons why I think conversation in IF generally works better than in other game genres: skill, creativity, and patience.

As I've suggested before, I think that perhaps it is a consequence of these games being created largely by writers rather than teams of programmers, designers, and artists, and I'm guessing it also has to do with the fact that most IF games are not commercial and lack the associated deadlines and budget constraints. It takes a lot of skill and time to write good conversation that creates depth for characters and their relationships, and even more to write it within a system where it is often pieced together at different points in time based on player actions. That takes a lot of planning, design, and testing. In some cases it demands some creative modification of the conversation system being used, but for the most part good, meaningful, and challenging conversation in games can be created with the tools and systems that are already out there. The more I play different IF games that have well-crafted conversation, the more I have come to realize this, and the more I believe that mainstream, graphical games can learn a lot from these implementations -- if only the developers would have any interest in it, which is to say, if only they thought that players would have any interest in it.

I also think the nature of the medium and the IF community is to encourage experimentation with different types of systems, and the result is that there have been some pretty creative solutions to what is (still) a complicated and mystifying issue. Sometimes that involves systems that combine different elements; Vespers, for instance, combines the TALK system with the ASK/TELL system, while a game like Short's Pytho's Mask combines topic-based conversation with multiple choice dialog trees. But often there is more that is designed under the hood, so to speak, in order to generate conversations that flow smoothly and are consistent with the events of the game regardless of the player's prior actions.

Over time, I'll try to review some of the games that I think do well at implementing conversation, with a focus on the mechanics, but also with a focus on the question of whether conversation systems like these could have a role in the more mainstream, graphical games industry. In the meantime, I'd be interested to hear if there are any mainstream games that people have encountered in the past that they felt utilized an effective conversation system.

4 comments:

Victor Gijsbers said...

In the meantime, I'd be interested to hear if there are any mainstream games that people have encountered in the past that they felt utilized an effective conversation system.

I believe that the multiple choice dialog trees has been used quite effectively in several mainstream games, without being hampered by the "lawnmower" effect. Examples are Planescape: Torment and The Witcher.

Though I must admit at this point that I've never really understood what the lawnmower effect is supposed to be. Why do multiple choice conversation systems encourage an "approach of trying all options, even if it requires re-initiating the conversation or using the save/restore approaches"? That approach seems to me plain boring. Just imagine saving and loading every time Torment gives you a conversation choice! That would cost an insane amount of time, and you would still need to choose with which choice you'd like to go on to the rest of the game. Or take The Witcher: sure you can save before you make an interesting conversation choice, but since the effects of that choice may only be happening 10 hours of play later, how are you going to "lawnmower" your way through it? You'll still have to choose a specific path, invest those 10 hours, and then see the results of your choice.

Rubes said...

That point is well taken, although I haven't played either of those games, so it's hard for me to comment on those implementations.

I will say, though, that I haven't played many games where the multiple-choice type conversation system has significant consequences that are only brought about many hours of play later. My experiences have been mostly the opposite, where one branch of a conversation, if it does have some gameplay significance at all, reveals its effects immediately or soon thereafter.

The most immediate example that comes to mind, in terms of mainstream graphical games, is the Baldur's Gate/Neverwinter Nights series. Most of the NPC conversations are of the multiple-choice variety, and my recollection is that most of the impact of the choices that are made (if any) occurs during or right upon completion of the conversation.

I agree that, in games where a multiple-choice conversation leads to choices with consequences much further down the line, the lawnmower approach (via save/restore) is not very realistic. But I think this speaks to the many roles of conversation in games, and when it exists for the player to choose a particular major path for gameplay, it's a different situation than when it exists for the purpose of discourse (like for characterization, story backdrop or progression, or information seeking). It's the latter instance that I think is more relevant here.

In a game like Neverwinter Nights, or for that matter Pytho's Mask (which I had planned on discussing in more depth later), players are often presented with a series of options for questions or responses to NPCs. But the mere presence of those options is a clue to the player that the author created content specifically for that option, and for many people like myself it's difficult to play through a conversation like that without feeling the need to try each of those options to reveal the content that is there.

It's similar to what Shamus said recently in his review of Guild Wars, when he was discussing the many sidequests in the game: "The other thing interfering with my enjoyment of the game is...that you’re not supposed to do every sidequest in the dang game. The completionist in me wouldn’t let me pass on all those sidequests because I felt like I’d be missing something."

In Pytho's Mask, for instance, when you bring up a topic for discussion, you're presented with multiple questions you could ask the NPC. Asking one question might lead to a series of others, with some information to gain. But in the end I'm just going to try every option, running through each choice lawnmower style until there's nothing left to ask. That's what much of the gameplay was like for me, at least at first; finding all of the topics to discuss with each NPC and mowing through each one. Mostly that's because there are rarely consequences to choosing one question over another, but even if there was some consequence (typically immediate, not sometime in the future) -- such as angering the NPC, or somehow cutting off some conversation branches -- the urge is always there to UNDO and go back to find out what information or outcome I may have missed because of that original choice.

It was often the same in Neverwinter Nights, especially in those conversations where the responses were given certain characteristics -- like if one response had some random chance of charming or tricking the NPC into revealing something. If it didn't work, the system usually gave you the chance to do it again, whether through alternative conversation branches or by saving and restoring.

emshort said...

There's a lot that goes into a conversation system other than the choice of the user interface -- which is important, but doesn't control things like pacing, NPC intelligence, design of scenes to be narratively effective, etc. Possibly you've played more IF that experimented with these effects than mainstream games that did?

I liked Planescape Torment, and I didn't lawnmower the conversations because there was just so much content there that I couldn't see spending that much time on it. (Then again, I didn't actually finish the game -- but that's mostly because I got my character stuck in a maze I found too irritating to complete, and didn't want to start over either.)

Rubes said...

Great point, Emily, and one I had intended to make at some point in this discussion -- somehow it got left out. My comments on Pytho's Mask were not intended to be a criticism necessarily, because I know the conversation system you devised was much more than just an interface. This is essentially what I was implying when I said that "often there is more that is designed under the hood, so to speak, in order to generate conversations that flow smoothly and are consistent with the events of the game regardless of the player's prior actions."

I like the experiments you've done with conversation systems, including Pytho's Mask, and I'll try to go into them in more detail.