As part of Gamasutra's Advanced I/O Week, Leigh Alexander examines some fundamental challenges that stand in front of the future of virtual reality games. When I was a child in the 1980s and early 1990s, neon-glowing wireframes, helmets and goggles stitched around the fringes of my awareness. Magazines, cartoons, cereal boxes. The virtual-reality gear was part of the fantasy of the future, along with the hoverboard and the jet pack. We kids who loved Super Nintendo and monolithic arcades internalized the idea that in the future, we would no longer play games on handhelds or controllers or at great glossy-knobbed digital altars with fat, sticky buttons. Instead, we'd all wear gloves and headgear, beetle-black bodysuits with articulated digits, and stand, silent, making slow movements with our hands and bodies like sports stars of science fiction. "Game" would become something not to do or play, but to enter -- you would be "in the game." Lots of the TV shows of my childhood featured plots where you could get trapped "in the game," like the game would be even more "real" if it were a place you might not even be able to come back from. These spaces contained so much possibility it was actually dangerous. Probably the most popular depiction of humankind's passion for digital fantasy spaces is Star Trek's Holodeck, a space where a computer can generate a fully-plausible, responsive replica of any place or circumstance the user requests. This isn't, of course, a "game" (unless you ask for there to be a game), but complete immersive simulation seems to hold limitless possibilities for anyone who likes the idea of designing places and things to do there. Virtual worlds via headgear have been part of the vision for game development for almost all its life, with Nintendo's short-lived Virtual Boy marking the most prominent early endeavor. While its high cost and the challenge of selling and explaining a 3D experience across two-dimensions doomed its launch, the dream is still alive. The Lawnmower Man (via IMDB) Crowdfunding, new technology, wild disruption of the traditional video game market and a brand new resurgence of developer interest have made the Oculus Rift virtual reality system one of the most talked-about platforms on the scene. It's hard to go to a game developer event these days without seeing someone toting a devkit. CastAR, another wearable system for VR and alternate reality games, beat its $400,000 Kickstarter funding goal in two days. Many design trends emerge out of a desire to fulfill a fantasy, but without proven forethought, they risk becoming expensive fads. 3D movies have also been desirable since the 1980s, but struggle to prove their true appeal after the novelty wears off. Second Life made the cover of Time magazine, a booming playground for the possibility of virtual selves promising all our interaction would take place through avatars; now it's a niche product, a desert of wishes that the fiction book "Snow Crash" could be real. If virtual reality games are to stick around this time, there are some design challenges people working in the space will need to find creative ways to tackle -- or use, or subvert.

How will VR games address physical boundaries?

Our bodies and minds process information given to us in virtual spaces much as they do in real ones, even when the difference is clear to our rational minds. In his extensive studies at Stanford's Virtual Human Interaction Lab, researcher and author Nick Yee found that if students wearing VR gear were confronted with a virtual pit spanned by a narrow plank, they often preferred to avoid the pit, even knowing they couldn't actually fall. Interestingly, Yee has reported that students who tried to cross the plank could lose their balance and even fall -- to conduct the studies, teachers' assistants had to be on hand to make sure nobody got hurt. The more a synthetic world behaves like a real one, the more human bodies will elicit genuine reactions that have complications for game design. A player will wear their headset and enter a virtual world while standing in a real room, with real walls. There's a limit, then, on how much walking the player can do, unless the game can somehow generate identical boundaries for players to avoid. Are the real world's physical boundaries a complication for game designers, or an interesting opportunity for them to subvert expectations? What about the headaches and nausea those new to VR experience?

Avatar effects: Who will we be in VR?

Yee's research has also found that players' behavior is different depending on what they think they look like. Players who have the perception of being taller are more confident in many ways than those who feel shorter in the virtual world; players who look older may be more cautious. Any time the self can be recreated virtually, the player brings in subtle prejudices from the real world about age, race, size, and concepts of beauty and strength. What a disappointing loss of opportunity for the virtual space if we only continue inhabiting familiar social rules and prejudices, and if digital spaces of complete possibility end up reproducing the disappointing limitations of reality. Who will we be in our virtual reality games? When we look down, will the hand we see be our own? Could that change the way we behave in the virtual space?

How will VR games use audio in new ways?

Another one of my favorite gems from Nick Yee's research, which I gleaned from his upcoming book The Proteus Paradox, is the takeaway that people trust their own physical responses so much that their perception of the real world can be influenced by imitations of their physical responses. In other words, survey participants looked at several pictures of models while wearing equipment. A tester would play a sound like the subject's own heart rate while some of the pictures were played. Subjects would later report those pictures as the most attractive, believing that the heart rate sound indicated their own arousal. Immersive environments aren't just about simulating visuals or the sound effects of a place. In alternate realities, how will game designers play with expectations players may have based on what they hear? Can designers use the effect of sound on belief to create more interesting experiences?

Can VR games move beyond the "holodeck" fantasy?

In order to use VR as a lasting and meaningful tool for the design of interactive entertainment, designers should let go of the "holodeck" fantasy for now and try to find ways for VR to subvert and transform, acting in interesting ways against our senses and expectations rather than always paralleling them. What if we could use VR design not to create plausible worlds with ordinary physical laws, but to experiment with the way the human body feels and acts in space?

How will we sell the VR game experience?

Hologram fantasies pervade all our media, but are sci-fi fans a large enough audience to sustain ongoing growth and development of VR tech? Just as Nintendo learned with the Virtual Boy in 1995, virtual reality can be a surprisingly tough sell -- you have to try it on to truly grasp exactly what it is and how it works, and that experience doesn't necessarily translate well on websites or on TV. Nintendo thought people would try the 3DS, fall in love with the 3D and buy it, but 3D handheld gaming didn't really take off; most 3DS owners seem to switch their 3D off these days. Virtual reality demands even more buy-in -- a wearable headpiece and an enduring interest in digital realms to begin with. Creative software design can help ensure that VR is more than just a flashy visual fad -- but it'll also be easier to market if it offers more than just a decades-old fantasy of a visual simulation you have to see to believe. How will we frame that message? Read more about VR and Advanced I/O on Gamasutra's special event page this week.