Dimensions: Change and Persistence

So how do designers categorize virtual worlds? And why would they want to categorize virtual worlds anyway?

Categorizations make explicit some of the choices available to designers. It’s all too easy to begin designing a virtual world having already made key decisions without even being aware of the fact. By laying out the options available to them, not only can designers be aware of what options are available to them, they are also forced to look at their solutions more analytically. Categorizations are particularly useful for seeing what the various combinations of design decisions imply about any resulting virtual world.

There are many high-level judgments that designers must make when considering the nature of the virtual worlds they wish to create—so many, in fact, that they merit an entire chapter of this book to themselves (Chapter 4, “World Design”). Most of these options are interdependent in some way, which makes them unsuitable as categorizations; others are so disjoint that they say nothing general beyond their own context.

Two, however, do combine to good effect: the degree to which a world can be changed by its players (sometimes called player impact); the degree to which changes persist over time. This model, originally devised by Raph Koster and Rich Vogel ¹, elegantly exposes what is perhaps the most important question designers must face, which determines the very soul of their creations: Whose world is it?

The two dimensions—change and persistence—are natural progressions from some of the differentiators applied to codebases. Players of MOOs all have full builder privileges, meaning they can add to their virtual world almost indiscriminately (they have direct access to the scripting language, which controls everything above the driver level). Players of AberMUDs have no such capability to change their world. Similarly, in Ultima Online the entire world and everything in it persists indefinitely—you can drop an object in your house and it will still be there weeks later. In MUD1, everything except the player characters’ details is periodically reinitialized.

The issue is one of content. Although developers throw around the term like everyone knows what it means, it’s actually quite hard to pin down. Essentially, content is that which the world provides to hold players’ interest. If players are consumers, content is what they consume.

As an analogy, content in virtual worlds is like what stand-up comedians call “material.” They write a routine stringing together jokes, observations, and witticisms, which they then deliver to an audience. If they’re really good, members of the audience may come back time and time again, but most won’t. After all, if you’ve heard a joke once, it’s not really as amusing when you hear it a second time; their material isn’t sticky. For performances in a 2,000-capacity theater, a single routine can last a comedian for half a year; on television with an audience of 20 million, it’s pretty well dead the moment it has been used.

Content in virtual worlds generally means giving people things to do, places to do it, and things to do it to. The mere presence of other players can be considered as a form of content, being as it is the primary reason most people play. Designers can’t design players, however, just facilitate their interactions; this kind of content is therefore said to be intangible.

Virtual worlds have another major draw, however, that of the virtual environment itself. This, designers can change directly; it’s tangible content. When designers talk about adding content to a world, they generally mean the tangible sort: that which can be coded or scripted, rather than that which emerges from interactions.

The combination of players and world gives rise to content so potent that people can be quite willing—indeed, positively enthusiastic—to repeat an experience over and over again. This makes virtual worlds incredibly sticky—much stickier than related leisure-time pursuits such as books, computer games, movies, and television. Only music is comparably sticky, with many people happy to listen to their same, favorite albums often and for extended periods ².

Players do nevertheless (as individuals) consume content. So where does new content originate? In some virtual worlds, only from the interactions between the players: MUD1 has had only minor changes to the virtual world since 1985, yet people still play it to this day. MUD1, however, is scaled just right for the number of players it attracts. For large virtual worlds such as EverQuest, there are far more people wanting to play than there are things for them to do. As players become increasingly practiced at the game and want to try out the more demanding challenges, there is greater demand for high-end experiences. Therefore, new tangible content (in the form of locations, monsters, treasure, and so on) must be added so that there’s enough around for everyone to eat their fill.

This kind of content can be added in one of two ways: within the context of the virtual world (for example, a nobleman hires a gang of workers to build a castle) or without (for example, a player or designer inserts a castle using a development tool). The distinction is quite marked: Does the world make the changes, or do the players? Put another way, do players have to prove new statements from a given set of axioms, or do they get to add axioms directly?

Some virtual worlds allow only partial access to the full majesty of their scripting language (perhaps through permission restrictions, perhaps through the use of a separate “builder language” itself implemented in the scripting language like regular commands). You might, for example, be able to create objects but not locations, or locations but not commands. In practice, though, these are one step beyond the point of no return: Either you can change the world using independent meta-actions (which is called building) or you can’t (in which case any changes must be through actions within the context of the virtual world itself). Thus, the measure of how much change a virtual world allows depends on the criteria that determine who gets to have the builder privileges.

For some worlds, for example most MOOs, everyone can build; for others, such as the heaviest role-playing MUSHes, only the world’s guardian coders can build (even though the architecture is as open as a MOO’s, and therefore anyone could in theory be allowed to build). In between these two extremes are worlds that allow changes by wider groups of coders/designers, by privileged appointees, by highly-experienced players, by players who have been playing for a certain time period, by players who pass an interview, by anyone who asks; it’s not quite a spectrum, but it’s close.

The other dimension under consideration here, persistence, is also more discrete than continuous. Persistence relates to the amount of a virtual world’s state that would be retained intact were the whole system to be shut down and restarted. All virtual worlds have some degree of persistence (after all, it’s part of the definition of the term “virtual world”), but exactly what they persist varies.

At the most basic end of the scale, all that a world persists is its initial state and the records for individual player characters. AberMUDs are like this. The next step involves persisting what the characters were carrying with them at the time (DikuMUDs), certain classes of objects such as player characters’ corpses (EverQuest), and so on all the way up to the entire world state (Ultima Online) and the entire world state plus all incrementally-added functionality (MOOs).

Persistence is more dependent on the available computer resources than is change. Put simply, the more you want to save, the longer it will take to save it and the more space it will take up. This is not, however, the usual reason why designers might prefer their world to have a relatively low degree of persistence. Adventure-oriented games in particular can have very complicated, inter-related tasks and puzzles that have far-reaching, game-wide effects; this makes them effectively impossible to disentangle from the state of the virtual world—you can’t unlaunch a rocket or unexplode a bomb. Designers want to be able to reinitialize these puzzles, because if something has taken perhaps weeks to implement, they don’t really want it to be single-use for the benefit of only a handful of players.

How can you reinitialize something that has all-embracing consequences, though? Reset strategies are discussed in detail in Chapter 4, “World Design,” but for this particular problem the short answer is that you can’t really reinitialize anything with such a large root system unless you initialize the entire virtual world. Full persistence in this situation would be a bad thing, because persistence is all about not reinitializing. Thus, designers of certain types of virtual worlds can have good reasons for not wanting to persist everything across reboots.

Okay, so let’s see how these concepts of change and persistence interact. Table 1.3 shows a six-by-six grid, with persistence increasing left-to-right and access to content creation increasing top-to-bottom. Major codebases and a number of important individual worlds are positioned in the grid depending on how far they satisfy the persistence and change criteria listed at the heads of the columns and rows, respectively.

Table 1.3 Persistence Versus Change

The first thing to notice is that there’s an apparent line running diagonally from the top left to the bottom right, with most of the virtual worlds appearing on or above it. What this says is that, in general, there’s a relationship between the number of people who have the ability to build things in a virtual world and the persistence of their creations. Note that this alone doesn’t say whether persistence implies building access or vice versa, just that the two go hand in hand.

Above the diagonal, fewer groups of people can build in the world, but what they build lasts just as long as for more relaxed regimes. Below the diagonal, more people can build, but what they build doesn’t last as long as for more open architectures. Given that there are plenty of virtual worlds above the diagonal and few below, we can deduce that increased persistence doesn’t really imply increased numbers of builders, but that increased numbers of builders does perhaps imply increased persistence. In other words, the more people who can add content directly to a virtual world, the more of that world will tend to persist.

Looking at the individual worlds in the grid, most commercial games appear on the horizontal line that indicates content can be added by trusted (because they’ve signed a contract) players but not automatically by anyone who happens to reach some world-defined level of expertise. Given that player-created tangible content is believed by many designers to be the future of virtual worlds, this reluctance to cross the line could present something of a problem. The topic is discussed at length in Chapter 5, “Life in the Virtual World.”

Okay, we’ve learned something, but what has any of this to do with the soul of virtual worlds?

Let’s examine Table 1.3 another way: as quadrants of nine squares each.

The top-left quadrant consists exclusively of adventure-oriented virtual worlds. The designers have created a world, and they’re strict about who can add to it. Whatever content changes they do allow while the world is running will only persist across a reboot under very particular conditions. Everything in the world is how it is for a reason, and has been constructed to be immediately captivating. The virtual world is so rich and complex and its components so interdependent that players’ changes aren’t ever going to be able to do it justice. Sure, players can make changes to the world through their actions within the world, but those changes don’t ever last for long because they disappear whenever the world is reinitialized. The world entirely belongs to the designers, like a movie entirely belongs to its director; it has little life beyond that of its own.

The top-right quadrant also emphasizes the integrity of the world. Only trusted people get to make changes. However, the world itself is more open-ended, and changes will persist for a long time. Whereas a volcanic eruption in a DikuMUD would last until the next reboot, in Asheron’s Call it would lead to a more or less permanent change to the environment. Some of the things the designers put into the world are not immediately interesting, but like seeds they may grow into something special later (or they may not). Players can make changes through in-context actions that have lasting effects. The world still belongs to the designers, but when players start to live in it, it gets a chance to evolve in ways the designers hadn’t necessarily considered.

The bottom-left quadrant is almost empty, with only MUD2 making an appearance. The world design is so tight that little persists from one reboot to another, but in between reboots those players who are of sufficient experience to understand the design can create tangible (albeit ephemeral) content. The designers ³ allow certain players to take control of the virtual world in a major way, but they wrest ownership back with every reboot.

The bottom-right quadrant contains almost entirely socially-oriented virtual worlds (with LPMUDs being the only exception). These often have little or no “game” aspect, and building is considered part of the fun. The original designers only create the core of the world and the means by which it can be extended; thereafter, they hand it over to the players to do with as they wish (although there’s a problem if what the players wish for is that the designers will take back control, as they famously did with LambdaMOO).

So, following this analysis we are at last able to answer the original question: Whose world is it?

• In the top-left quadrant, the world belongs to the designers.

• In the top-right quadrant, it also belongs to the designers, but players have a stake because the changes they make through their in-world actions can change the landscape.

• In the bottom-left quadrant, the world still belongs to the designers. Players are loaned world-changing powers, but come midnight their carriages turn back into pumpkins.

• In the bottom-right quadrant, the world belongs to the players.

When designers begin work on a new virtual world, the question of who is to own it should be uppermost in their minds: It really does encapsulate the soul of the world! Of course designers will have a vision of their world, and of course they will consider themselves to be better designers than are their players (not unreasonably so, despite what players ⁴ may think). Players are people, though, and need to be thought of as such. How much are the designers willing to trust them to add good new content?

• Not at all? Then go for low persistence and low change.

• A lot, if they stick to the rules? Then go for high persistence and low change.

• A lot, but not for long? Then go for low persistence and high change.

• Implicitly? Then go for high persistence and high change.

Perhaps the best expression of this difference is seen in the comparison between the early advertising slogans of Verant (makers of EverQuest) and Skotos (makers of Castle Marrach):

• Verant: You’re in Our World Now.

• Skotos: Why Yes, I am God.

Skotos’ games have only a fraction of the players that EverQuest has, but their slogan sells more T-shirts.