In September 2010, eight months after the release of their space epic Mass Effect 2, developers BioWare discussed some of the strange statistics they were getting from people who were playing the game. Amidst the talk about one gamer who took 66 hours to complete the game, and the complaints over why more people didn't play as female Shepard, an interesting nugget of information lay more or less unexplained. PC gamers were more likely to finish the optional quest for Miranda, one of the non-player characters, a quest described by BioWare themselves as having "a touchy-feely plot". Another character - the emotionless, bloodthirsty Krogan called Grunt - was favored by XBox 360 players more.
What makes a PC gamer more likely to choose the emotional, family-issues quest over a killing spree?
The more game developers look at their own creations, the more they see unusual patterns emerging. Why do some people prefer to play as support classes? Why do some feel the need to complete every last sidequest? What makes a PC gamer more likely to choose the emotional, family-issues quest over a killing spree?
A growing group of academic researchers think they can explain these phenomena - and moreover, they think that understanding these patterns of behavior might lead to better game design in the future. At this year's Computational Intelligence in Games conference in Seoul, South Korea, I met one such researcher who had some startling results to present about an experiment he conducted in another BioWare RPG - 2002's Neverwinter Nights.
Giel Van Lankveld came into computer science via an unusual route - four years studying experimental psychology. His PhD supervisor, Pieter Spronck at the Netherlands' Tilburg University , was interested in pursuing work to help model and understand how gamers behave within games, and hoped that Giel's psychology background would bring a new angle to the research area. Understanding gamers and learning about what kind of people they are is important to game researchers, because doing it in real time allows games to become "adaptive" - redesigned to be personal to you, in ways so subtle you may not even notice.
Picture this: You're playing the next Deus Ex game. You're taking the stealth approach a lot, and the game notices this. In fact, over the first hour or two of the game, it's built up a profile of what kind of gamer you are. Now it's got enough information to confidently redesign the game to be better for you - it invents new upgrades for you to purchase that are specifically catered to stealth players. It rewrites later missions to have more hidden entrances. Not only that, but it makes the game more interesting - increasing the frequency of alarm panels and making guards more alert. You and every other gamer on the planet play the same game at heart, but the finer details are tweaked to better suit you.
Both the research world and the game industry are keen to get this technology into games, but the first step towards doing this is understanding what players are like. "Each player has a mental model of how the game works, but we can't open up a player's mind to look at it," Giel told me as he explained how his research started. "We need to look at the player's behavior and infer how accurate their model [of the game rules] is from this behavior." So Giel began with a simple series of experiments investigating game difficulty. He wrote a program that watched participants play a simple game and then estimated how well the player understood the basic rules of the game and the strategies that arose as a result. Giel's hypothesis was that players who had a better understanding of the game's rules would be better at formulating strategies for defeating the enemies they faced. The data collected showed promise, but left Giel wanting more.