If you’ve seen anyone wearing a virtual reality headset, you’ve probably wondered how roaming around fully 3D worlds while their real body stands still doesn’t instantly flick the puke switch. VR games have come a long way in tricking your brain to let the good immersive times roll, but keeping a few dozen enthusiasts from yakking at press events is a far cry from safekeeping the millions who will soon boot up their Oculus Rifts, HTC Vives, and PlayStation VRs. If the genre is to survive past its early days, VR game designers need to seek and destroy all the discombobulating triggers for “VR Sickness” they can—which they are, mostly through trial and error.

The good news is, by the time you don your goofy VR headslab and soar into immersive worlds, a lot of the weirdness has been ironed out. Every developer I’ve talked to has assured me that they’ve amped up their playtests and sickened themselves to ensure their game doesn’t get infamous for gutting players—like Resident Evil 7 just became after its demo decimated those that played it at this year’s E3 convention. Big studios are scrambling to crack the code as quickly as the nimbler little guys, but the quest to make VR viable is complex. It’s software messing with how your brain interprets the visual stimuli hitting your eyes versus your body’s biological spatial awareness, something evolution has been fine-tuning for millennia.

When you put on a VR headset, the screen in front of one eye shows a slightly different picture than the other to give the illusion of stereoscopic vision, mimicking how your eyeballs see depth in the real world. But if either of those pictures are out-of-sync or the images ever dip below ideal performance, your inner ear sounds the alarm and your lunch rushes up to the back of your throat. When the digital world fails your brain’s reality test, accidents happen.

VR is still in its Wild West stage; most developers are just releasing their first VR games, so the pressure’s on to get it right the first time. That means quick learning and lots (and lots and lots) of testing, but developers have nailed down some hard-and-fast rules to keep their games from pushing the player’s puke button.


Frame Rate is Key

“In a game that you’re playing on a flatscreen, you might program it for graphic fidelity knowing that there is going to be times that there’s a lot of stuff on the screen, and you can take a hit and, say it’s 60 frames per second 99.9 percent of the time but then there’s that 0.1 percent where it drops out—” says Andrew Eiche, chief developer at the Austin-based VR game studio Owlchemy Labs. “In VR, it has to be 90 frames per second 100 percent of the time because even dropping a frame or two is going to make you sick.”

At about 18 frames per second, Eiche says, we stop seeing things as individual pictures and start seeing them as continuous motion—as a movie. When you put on a VR headset, it requires a much higher framerate to achieve the same effect. In a way, VR is a victim of its own high ambitions: if a game runs below 90 frames per second, the seams pop out when you quickly turn your head, as you do when looking around the real world. Good VR is basically tricking the mind, says Eiche.

But you won’t find a photorealistic world tricking your brain when you boot up Owlchemy Labs’ first VR game, Job Simulator. Instead, you sit in a cartoonish “workplace” recreated by future robots who throw the player in a mundane setting and seeing how long it takes them to rampage through a fake office. The trickery lies in making the experience seamless while cleverly preventing the player from making themselves sick.


Protect the Player

In Job Simulator players can’t move beyond their little cubicles. Owlchemy found that moving their game character while the player sits still, what the VR industry calls “artificial locomotion,” was a regular trigger for nausea—at least this early in VR’s lifespan. So they avoided the risk by restricting movement to “teleporting” from static position to static position. It ain’t pretty, but you don’t need much locomotion to enjoy Job Simulator. Bullet dodged.

“You have a natural sense of where your body is in space. As long as the world you’re in matches what you think your body is doing, you’re basically going to eliminate any feeling of discomfort,” says Halcyone “Cy” Wise, multi-hat wearing community wrangler at Owlchemy Labs. That’s why Owlchemy only recommends the 1:1 or ‘fits in a room’ movement scale.

But the call to zoom around digital worlds faster than a player can walk is too tantalizing for the fast-paced action and shooter genres. UK developer Rebellion snapped up the rights to the ‘80s arcade classic Battlezone to revamp it into a full VR tank-battling simulator by the same name. Yet charging into first-person combat in a vehicle is the definition of artificial locomotion in VR, with all its potentially nauseating pitfalls.

“It became obvious quite early on that the undulating landscapes that cause frequent oscillations in the player’s position were triggering that kind of motion sickness. One of the first ways we tackled that was to decouple the head position camera from the vehicle itself,” says Steve Bristow, lead designer for Battlezone at Rebellion Developments. “It mimics what you’d feel on a surfboard: your body rocks around but you naturally try to keep your head level.”

Their second big development was the cockpit: put something stable in the foreground and you’ll ground the player’s vision, just like they’re staring out the front window over a car dashboard. It’s not unique to Battlezone—you can find cockpits in other VR vehicle shooters like EVE: Valkyrie—but it works. Because you’re actually sitting in a chair, and the cockpit conveys that your character is sitting in a chair, your brain is cool with a vehicle moving around you in-game (unless you also get sick riding in cars).

And how do you cure car sickness? Stare out at the horizon. With a fast-moving game like Battlezone, Rebellion found they needed wide open spaces and a level horizon for a distant reference point. If you nestle players deep in canyons without a horizon line, for example, that motion sickness comes back.

But even honing your interface isn’t enough—you have to protect players from themselves. Like babies toddling down the street before they’ve mastered one-foot-then-another, gamers dropped in VR worlds will probably zoom around and make themselves sick. Battlezone starts with a sequence that slowly introduces the looking, moving and shooting mechanics to ease players into the VR experience. Gamers may grumble at tutorials—what’s sometimes called hand-holding—but it’s far better than blindly walking into a digital tilt-a-whirl.

If there’s any game designer seasoned in first-person tutorials, it’s Jaime Griesemer, lead designer of the upcoming PlayStation VR exclusive Golem from Highwire Games. A decade and a half ago, the original Xbox launched with the game-changing Halo:Combat Evolved, and Griesemer spearheaded its tutorial, walking the player through their first moments with the newly-woken Master Chief. Then, as now, introducing players to a whole new paradigm of moving and looking took time for them to adapt.

But when Griesemer and his Bungie buddies left the staid shores of Halodom and formed Highwire Games last year to delve into VR, they quickly learned that you couldn’t zoom around that fast. In fact, best if you don’t even try adapting current games into VR; you should just build your game with VR’s limitations in mind from the get-go.


Change the Controls

Griesemer is pretty sure about this:

In the tweet above Griesemer is referring to the Resident Evil 7 demo that wiped out players by letting them look around with their head and change their view with the right stick, a combo that (almost) launched a thousand yaks. (Though Griesemer does concede that a hot, muggy, chaotic convention floor is a horrible place to play an intense new VR experience anyway—hence why Golem wasn’t at E3 this year).

In Golem, the player moves by gently inclining their head one way or another. The developers found that the player naturally follows the motion with their upper body, which mimics how you automatically lean when walking, tricking your brain’s vestibular system (inner ear) into expecting locomotion. The whole game deliberately moves at a slower pace, but that’s the price you pay for virtual reality.

They even folded the player’s real life immobility and slow movement into the game’s narrative: the player inhabits the body of a young girl paralyzed from the waist down, who herself magically possesses the titular golems. And obviously, the golems lumber around with exaggerated lethargy. In the hindsight of a future historian, Golem and the entire first generation of VR gaming pioneers are likely to be seen as genre tutorials for how to let players adapt to the motion and behavior inside virtual reality.

As Griesemer (and every other developer in this story) found, stick around in VR gaming long enough and you’ll noticeably reduce the number of triggers making you sick. People can get so acclimated that VR studios have to keep finding folks with no VR experience to test their games and troubleshoot triggers; it’s Wise’s job at Owlchemy Labs to scare up “fresh” subjects, which lately means seeking non-gamer significant others and parents.

Unfortunately there may end up being some gamers who will never be able to handle VR. Science hasn’t gotten back to us about whether a certain segment of the population is doomed to automatic nausea, and people’s susceptibility varies wildly. Regardless, progress must be made. We’ll have to leave some behind when we sail the straight way to VR Valhalla.


Leave the Unworthy Behind

The first generation of games will deliver eye-opening VR experiences—ones that might look lame compared to the mind-bending stuff developers will release in the coming years once they truly harness virtual reality technology. But pushing the envelope always means abandoning the stragglers, like gaming did when some players got stymied by the 3D motion in the DOS classics Castle Wolfenstein and Doom and never followed us into the future. For the rest of us, game developers continue to iron out the kinks that trigger VR sickness.

“Once you’re over that initial hurdle, and the few that are going to get left behind are left behind, unfortunately, that’s where the real exciting things will happen,” says Griesemer. “What are these new worlds we can build for people to inhabit? The more compelling we can make the experiences people are having in VR, the more willing they’ll be able to get themselves over the hump and adapt.”

But it’s important to note that the actual VR headset technology doesn’t need to evolve to safeguard players. “If your players are getting sick in your game, you made a choice to make that happen,” says Owlchemy Labs’ Eiche. And he’s not alone in laying blame at the feet of game makers. The responsibility to keep players from getting nauseous now lies with the developers, Valve lead writer Chet Faliszek told an audience at last September’s EGX game convention.

“The idea that VR must get you sick is [bullshit],” Faliszek said. “As consumers and people in the community, hold developers to it. They shouldn’t be making you sick. It’s no longer the hardware’s fault any more. It’s the developers making choices that are making you sick. Tell them that you don’t want that.”

Owlchemy Labs’ founder Alex Schwartz and Wise help run the grassroots VR developer community in Austin, Texas, and they see these offenders all the time—fresh-faced programmers convinced that they’ve “solved” artificial locomotion who end up reacquainting testers with their dinners. That’s why Eiche strictly advises new developers to get these VR baby steps right before trying to make the next Call of Duty in VR. If folks have a bad experience in these early days, they’ll forever avoid VR like the plague—and tell their friends to do likewise.

“A great example I heard was: imagine everyone told you how awesome strawberries tasted but the first one you ate was a rotten strawberry. That’s going to paint your perspective forever,” says Eiche.

Lest this be a lesson against innovation, Griesemer insists that developers not stop experimenting with the genre. It’s too early to act like you have it all figured out, he says. The middle ground sounds like a lot of what studio developers are already doing with their extensive testing: safeguarding their players by sacrificing their own bodies on the altar of progress.

“A lot of where I see people going wrong is because they’re too timid about breaking the rules. They’re locking in on how things are going to be in VR too fast. So when people say it has to be 1:1 [instant player to character movement], well, you aren’t going to find it—because you stopped looking,” says Griesemer.

Preventing VR Nausea

Even the iron stomachs of seasoned game developers fail after extended wonky VR sessions. Here are a few tips from the pros if your inner ear hits the panic button.

1. Take a VR Timeout—aka, take the rest of the day and go home. It’s not worth getting yourself even sicker.

2. Close one eye, which shuts off the depth disparity. Owlchemy Labs devs actually use “One Eye” as a code word for how long they lasted before getting sick.

3. Go outside. Sometimes you just need to get a breath of fresh air and a taste of the real world, says Rebellion Developments. Breathe. Breeeeeathe.

4. Ginger! Highwire Games devs have ginger chews lying around, as eating the root (or candies thereof) stabilizes nausea.

5. Limit your playtime to under an hour. I know we’re just repeating what your mom said when you were eight. We’re just worried about you, OK?