An Introduction to World Building
by Dave Rickey
One day a group of scientists got together and decided that man had come
a long way and no longer needed God. So they picked one scientist to go and
tell Him that they were done with Him.
I've fallen into something of a rut, complaining about how the industry is making the same mistakes in the same ways (both the mistakes and my complaints), and it's time to break that pattern and talk about some of the ways it is moving forward.
One of those ways is in the sheer scale of the worlds. In scaled units, all of UO's original gameworld amounted to about 2 square miles. EQ's original world was about 7 miles2. Asheron's Call exceeded 500 miles2, but much of that was effectively empty (in apparent reaction to this, AC2 was 25 miles2). Dark Age of Camelot's original map was 54 miles2, Star Wars Galaxies had 8 planets of 100 miles2 each, City of Heroes was roughly 50 miles2, and Horizons a mind-boggling 15,000 square miles.
Obviously size isn't everything. Most of AC's 500 and Horizon's 15000 square miles of space is bland, uninteresting, and populated randomly (and often sparsely) with monsters that are obviously there for no particular reason except to be there. This space serves little gameplay purpose except to separate more interesting locations. The majority of the world doesn't feel like a world, but more like an empty stage, forgotten by the cast and ignored by the audience.
The issue of world size is tied together with the problem of world building, and more specifically with world populating. It is comparatively simple to create the terrain for a world of arbitrary size, and with the onward march of Moore's Law it is becoming feasible to run the hundreds of thousands of NPC's it would take to fill such a world. But these aren't just worlds, they are games, and if the game is to be interesting then the things that fill it need to be as well. This creates a tension between quantity and quality of content. Purely algorithmic methods of world building can fill worlds of arbitrary size, but tend to have uninteresting, bland results. Purely hand-built worlds are more interesting and engaging, but highly labor intensive (World of Warcraft is rumored to have spent most of its $25M budget on just that). The road forward is largely a matter of improving the tools to automate as much of the process as feasible while still maintaining that spark of creativity that comes from human effort. This tension goes back to the roots of MMO games in MUD's, and is thrown into sharp relief in the modern games where payroll for artists and world builders represents the bulk of development costs.
Ultima Online was originally a highly procedural world, with the plan of being based on a virtual ecology system where content would be created by emergent systems. The theory was that as the player's interacted with the world, they would create interesting situations that they would then have to resolve (players kill the wolves, which increases the sheep population, which attracts dragons, and so on). There were three basic problems with this:
EverQuest was built with different principles, every monster and NPC in EQ was placed by hand, every encounter tweaked to work with the built-in creature AI in very precise ways. Literally man-years of time were expended defining creatures, setting loot tables, and setting up spawns. This approach showed certain disadvantages of its own:
Asheron's Call used almost purely algorithmic methods. Terrain was created by painting heightfields and defining climate, and these would determine creatures that would appear in a given area. This allowed large amounts of terrain to be populated, filling the vast majority of AC's 500 square miles. Dungeons were also assembled from random blocks being fitted together, which allowed hundreds of them to be built. The drawbacks of this approach were:
These three approaches to world-building each has their own advantages and disadvantages, and each used in exclusion for a game will imprint those onto the resulting world. The manual approach has had the best results to date, but it has a problem with scaling. Once the tools have been improved as much as feasible, the only way to build a larger world is to hire more world builders and have them spend more time. After 5 years EQ has $20M or more invested in content, as does DAoC, and the upcoming World of Warcraft has made a similar investment. Either budgets will have to continue to climb towards the $100M mark (probably not an option in the next decade), other methods will be explored, or each game type is going to become the unassailable turf of two or three established games, with an entrance cost too high to be practical.
The best example of the potential of the algorithmic approach is in City of Heroes. In CoH, the world zones are subdivided into sections that are assigned difficulty levels. Within those sections, areas are defined as having certain properties (Rooftop, parking lot, warehouse, etc.). Enemies of various kinds are assigned to an area, and are populated into the world at run time according to their affinity to that area. The real innovation of the CoH approach is that these enemies do not appear as lonely, randomly placed singletons, but rather come in packages that have an apparent purpose. A street gang spawn can be a "Mugging", "Vandalism", "Burglary", and so on, and will include victims spawned for the purpose. This can lead to some oddities (like a bunch of thugs trying to break into a bus stop), but overall it does a good job of giving verisimilitude to the encounters.
In the next few columns, I'm going to describe a method of world building that takes from all three approaches in a way that hopefully conserves the strengths of each while allowing them to cover each other's weaknesses.