'Prom Week' breaks new ground in computer game design

Nominated for technical excellence award at Indie Games Festival, Prom Week is a game about social relationships driven by an innovative artificial intelligence system

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Prom Week's core team (left to right): Michael Treanor, Aaron Reed, Josh McCoy, Ben Samuel, Michael Mateas, and Noah Wardrip-Fruin. Photo by Robin Crough.

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Prom Week allows players to shape the social lives of high school students.

All the adolescent angst, hallway drama, and social scheming of the week before the high school prom play out in Prom Week, an online computer game developed by a team of students and faculty at UC Santa Cruz. The possibilities are endless in the unscripted story lines of the game, which uses a sophisticated artificial intelligence system to enable players to shape the social lives of a group of 18 high school students.

"Prom Week is a game where the game play revolves around social interaction," said lead developer Josh McCoy, a graduate student in UCSC's Baskin School of Engineering who led the development of the artificial intelligence (AI) system at the core of the game. "This was AI-based game design, so the challenge was to create a model of social interaction and then turn it into a game that's vibrant and fun to play."

In January, Prom Week was selected as a finalist for the technical excellence award at the upcoming Independent Games Festival (IGF) in San Francisco. It is also in the running for the audience choice award, and a special preview release of the game has been made available on the team's web site. The game's official release is on Valentine's Day (Tuesday, February 14), when it will be available to play for free on Facebook and other web platforms.

In the game, each "level" is a different character's story, and the player is presented with goals for the character, such as getting a date with that cute boy in algebra class. The player chooses social actions for their character to take, such as flirting or bragging, and the game plays out the resulting interaction with dialogue and responses that depend on the personalities and back stories of the characters involved. The game's AI system not only generates an interaction appropriate to those characters, it also keeps track of the evolving relationships among the characters as the game proceeds.

"What the characters say to each other and how they respond is dependent on this growing back story of interactions that the player has caused to happen," explained Michael Mateas, associate professor of computer science in the Baskin School of Engineering and director of the Center for Games and Playable Media at UC Santa Cruz.

Mateas and Noah Wardrip-Fruin, also an associate professor of computer science, are the faculty advisers and executive producers for the Prom Week team. They run the Expressive Intelligence Studio (EIS), which focuses on the development of advanced AI to enable new kinds of playable experiences. Prom Week combines rich social simulation with concrete characters in a way that hasn't been done before, Mateas said. "In most games today, you either have concrete characters that have specific personalities and pre-authored dialogue, or you have rich social simulation like you find in the Sims, but none of the characters has a very well-specified personality or back story."



The social simulation in Prom Week is based in large part on a set of 5,000 social considerations or "rules" that determine what characters want to do and how they respond to the actions of others. To come up with those rules, the team studied social interactions in movies and television shows. "It was like ethnographic note-taking, but with media," said Wardrip-Fruin. "The team would sit down and watch Mean Girls or Sex and the City and identify recurring patterns of social interactions."

The result is a game that captures the complicated and unpredictable nature of human relationships. "It feels fundamentally different from the way social interactions work in other games," said Prom Week's lead writer, graduate student Aaron Reed. "In the same way that Angry Birds allows you to use the physics of the game to come up with alternate ways to solve puzzles, we have a system that lets you solve social situations in different ways that are not predetermined by us."

For this reason, the team often refers to Prom Week's AI system, called Comme il Faut (French for "as is proper"), as a "social physics engine." As Wardrip-Fruin explains, its function is analogous to that of the physics simulations that help make today's blockbuster videogames so visually compelling. "Some of those games have rich unexpected game play because they use a physics engine that keeps track of physical objects in the world of the game. But games about social relationships haven't had that kind of richness," he said.

The combination of computational sophistication and social complexity in Prom Week reflects the diverse multidisciplinary backgrounds of the core team's student members, all currently pursuing Ph.D.s in computer science. Lead developer McCoy's background includes B.A. degrees in sociology and anthropology as well as computer science. Lead writer Reed is a well-known author of interactive fiction and earned an M.F.A. in digital arts and new media at UCSC before joining EIS. Lead game-play designer Michael Treanor also has an M.F.A in digital arts and new media and experience in videogame design. Lead engineer Ben Samuel has B.A. degrees in both computer science and theater arts and is a professional actor, starring in the new Hulu television series Battleground.

"I don't think this game could have been made without students with those kinds of interdisciplinary backgrounds," said Wardrip-Fruin.

In addition to the core team, many other graduate students contributed to the project, as well as undergraduates in computer game design and other programs. Several team members noted that the academic environment at UC Santa Cruz was essential to the making of Prom Week, not only fostering cross-disciplinary interactions but also allowing the team to spend years on an ambitious project for which there was no guarantee of success.

"Our first estimates of how long it would take were horribly optimistic, but that's just the nature of doing something that no one's ever done before," Mateas said.

Now that the game is finished, members of the team are finally able to see how players respond to it. "We've already seen a couple of different styles of play," Reed said. "Some people play casually, just to see what they can make happen. Others really get into the strategy and planning their moves to achieve goals. But it's really exciting to see people respond to the characters and to see that the system is successfully performing a character that we conceived of."

Other groups at the Center for Games and Playable Media are already adapting Prom Week's AI system for use in other games, including "serious games" for teaching conflict resolution and for cultural training purposes. "It provides a general framework for managing and modeling social interactions," Mateas said. "We have three ongoing projects that are adapting it for other kinds of games."

The work on Prom Week was funded in part by the National Science Foundation.