When Warren Spector goes shopping for games, he sometimes feels cynical, seeing shelves full of what he sees as "me-too" product -- legions of licensed titles, sequels and derivatives. "But current game development isn't quite so bleak in environment, and there really is an awful lot of creative risk-taking going on right now," he says. The veteran designer, known for his work on Deus Ex and System Shock, recently joined the University of Texas at Austin to direct game development education programs. Now, speaking at New York University Game Center's annual PRACTICE conference on game design, he says that what unites the broad variety of his favorite games is that they exploit the power of emergent gameplay. In his "oversimplified universe," there are scripted, linear games like BioShock Infinite, The Walking Dead and Heavy Rain, and player-driven games like Deus Ex and Dishonored. "I want to focus mostly on games that put players in control of the experience," Spector says -- with the important caveat that he "absolutely adored" many linear experiences, including Heavy Rain and Walking Dead. "Games that don't offer quote-unquote 'real choices' might be just fine," he suggests. "Some people may want a game that's all about squeezing a virtual trigger, or moving forward like a shark, or solving a puzzle that shows more about how clever the designer is, rather than how clever they are. I'm just more interested in emergence than in scripted adventures... and I believe once players get a taste of that kind of game, it's very hard for them to go back." Spector's favorite definition of the term "emergence" is "engines of perpetual novelty." His historic collaborators, like Harvey Smith and Randy Smith (unrelated) agree -- the latter Smith sees "less pre-scripted agenda" on the part of the developer, whereby anything can happen, and players share authorship with developers. Doug Church believes firmly in the future of procedurally-generated narrative, and says emergence empowers player choice, even while complexity and scale leads to cost and risk. "[I don't think] this is just 'Warren and his buddies over beers thinking we're smarter than everyone else', "says Spector, citing the work of developers like Richard Garriott, BioWare, Rockstar, Lionhead and Maxis for working closely alongside emergent gameplay concepts." When you leave a book to go to bed, the words don't rearrange themselves as you sleep (although we could probably do that now, he jokes). But games can keep that sense of life and novelty, giving every player a different experience that's unique every time they play -- a goal distinct from linear narratives where choice-making turns players into "semi-intelligent button pushers". That games can generate player-driven experiences are "the only thing that sets us apart in any meaningful way from other mediums, so I think we have a moral obligation to enlist players as collaborators in the telling of a story." How can designers approach their work to better embrace emergent design? If you can reasonably predict the player's end to end experience, you may want to rethink. And a fail-learn-retry model that forces players to hit the same switch or pass the same jump scare multiple times until they learn how to avoid it isn't good gome design," he says. You may thrill your players or even make them cry, but "you're not sharing the spotlight." It's true that games where every player's experience is basically the same may have stronger traditional stories, but games focused on emergence and giving players tools to discoer or create re more game-like, spector says. "Embrace the idea that your job is to bound the player experience, to put a sort of creative box around it -- but you don't determine the player experience. It's not about 'here's where every player does X.'" Create global rules versus specific, instanced behavior of objects and characters; build interlocking systems that are predictable and consistent (some objects are flammable, some guards are light-sensitive, the player has torches) but not pre-determined. Have a variety of object properties with plausible or simulated effects ("let water be water") that players can learn and engage with. "You can make a plan and execute it, intuiting on an experience you had earlier in the game, almost like the real world," Spector says. "How much more powerful is that?" It can't be overstated these are significant technical and artistic challenges, he says. Players will break the game. They might be intimidated by the freedom to make decisions. But it's essential to try to go further than what designers can create by planning the player's experience in advance. "Embrace this idea that the most interesting games are those that let players devise personally-meaningful goals, formulate and execute plans to achieve their goals," says Spector. "Plans must be devised by the player; it's not about how clever you are."