In his GDC talk on Wednesday, Maxis' Chris Hecker split his talk into three sections: what user-generated content is, how to use it, and why to use it.

He began by setting up a partial taxonomy of axes for UGC, including aesthetic content versus behaviorial content, parameterization versus raw creation, as well as a more vague axis of accessibility.

As examples of UGC interfaces that demonstrate various combinations of these descriptions, Hecker went through a number of screenshots -- Wii Miis and City of Heroes for parameterization and aesthetics; Spore creatures and mods for aesthetics and creation; Final Fantasy XII's menu-driven battle queue system for behavior and parameterization; Banjo-Kazooie: Nuts & Bolts and the Flash game Fantastic Contraption for behavior and creation.

The "edit/test" cycle, Hecker says, is an ongoing loop that users cycle through when creating content -- which occurs in gameplay as well as players try different mechanics and approaches, but on a much faster scale. With user-generated content, that cycle can end up lengthening to the point that it approaches game development. That can limit accessibility and shrink the potential audience for such content.

It's a difficult problem: "There are a lot of companies out there trying to make this behavior/creation stuff more accessible," he noted, throwing out examples like Whirled and Second Life. "I hope that somebody succeeds, but at least people are trying."

When the edit/test cycle stretches out enough, however, it can also create new full-scale games -- Civilization IV and Half-Life were both released as finished products, but resultant user-made mods ended up being polished into commercial game releases in the form of Civilization IV: Beyond the Sword and Counter-Strike.

"But is that still user-generated content at this point?" asked Hecker. If so, is Diablo II's randomly-generated loot UGC? The line is blurry, he argued, citing other games like EVE Online as titles that can arguably be considered to rely heavily on user-generated content, even just in the form of behavior and social and economic conventions -- such as in the recent widely-reported conquest of a major in-game faction by another.

"It's hard to impress upon you how important this is," he said of the entirely player-driven event. "This is thousands of dollars and hours of thousands of hours of people's time vaporized."

After going through an impressive selection of Spore content, Hecker showed a picture of his young daughter: "Here's a piece of user-generated content I'm particularly proud of," he said, but also noted her shirt -- which was ordered from the website Threadless and which he also considers to be user-generated content.

Ventures like Threadless date back to business card-on-demand outfits, which have existed since the 1970s; the model now spreads to a huge range of consumer products, including competing t-shirt sites as well as Nike shoes and emerging services that "print" users' game characters in resin.

"This is the end result of where all this stuff is going," he said, showing a picture of an early version of a self-replicating robot. "This thing can print copies of itself."

The idea of self-replicating robots was considered by early computer pioneer John von Neumann, who imagined that such devices could be used to explore the universe, with robots "spawning" themselves and exploring further at exponential levels -- the entire galaxy could theoretically be explored in only a single-digit percentage of the time it took for the galaxy itself to form.

(Unannounced, industry legend Will Wright took the stage for one of his notorious "Russian Space Minutes." He explained that the space shuttle was developed as a reusable way to get into space. Although it ended up being about 100 times as expensive to reach orbit as was originally intended, the program continued.

Meanwhile, the Russians were watching the U.S. shuttle launch in 1981, and were convinced that the purpose of the shuttle was to steal Soviet spy satellites. The Russians ended up building their own shuttle -- but unlike its U.S. counterpart, it was an armed weapons platform. Though it had a successful launch, only a year later the Berlin wall fell, and the space program was shut down; the enormous cost of the shuttle may have been one factor that led to the bankruptcy.)

After returning to the stage, Hecker declared that the frequently-stated "1 percent rule" of user-generated content, which declares that for every one creator, there are ten "synthesizers" and 100 consumers, is actually a fallacy.

He pointed to Wikipedia as supporting evidence -- even though a tiny fraction of users provide the overwhelming bulk of edits to Wikipedia, it actually turns out that meaningful, substantial edits (as opposed to merely minor changes or grammar corrections) are spread across a much, much wider base of users who simply have particular interests in specific areas.

"I think the fundamental question for the next ten years of game design is the following: how do games mean?" Hecker said. That is, "How does meaning happen in our art form?"

Other forms have established the answer to that question more clearly, he said. Frank Lantz and Jonathan Blow have spoken against the message model of meaning, where the designer imbues the work with a meaning to be delivered to the player -- Hecker said this is possibly too prescriptive.

Then there is the model that focuses strongly on immersing players into a meaningful world, letting the player discover cues of meaning in a "travelogue" way, as advanced by Steve Gaynor (of the Fullbright blog) and the studio Tale of Tales. "I'm not so sure," Hecker said. "It still seems very top-down and authorial," because the player is still finding designed meaning that has been deposited into the world.

Then there is the model of abdicating authorship, as advanced by Mark LeBlanc and Doug Churg -- that "a three-second arc in Quake has more meaning than a full game of Myst," because the latter is completely authored and preset.

"I'm wondering if there's an interpretive model of meaning that might be better," Hecker offered. As designer Clint Hocking said during his own talk today, "We need to nurture players when they are trying to express themselves. ...It's a beautiful thing to master something, but it's also a beautiful thing to not have mastered something."

Referring to Kant's distinction between the beautiful and the sublime, with the latter having a certain amount of fear of the overwhelming, Hecker categorized Hocking calling a lack of mastery having the potential for beauty, as being sublime.

Rather than simply being a platform for making money or a platform for specific expression, games can be a "platform for meaning," Hecker submitted. By "giving up some of our attempting to do it, we can actually convey more meaning for the player."