Pure Shows Off Fun of 'Artistic' Physics

"The tricks in this game are pure fantasy. Do not attempt them in real life."

That's the warning that flashes when you first boot up Pure, the giddily awesome new ATV-racing game. And no wonder: Pure sends you driving around mudsplacked tracks with furious velocity, racing up steep hills and then -- woo hoo! -- launching yourself with escape-trajectory speed into the air. The goal is to pull off stunts -- 720s, forward rolls, one-armed handstands -- so you can earn "boost," which lets you go higher and, of course, pull off even crazier stunts.

After about 15 minutes, I was scraping the bottom edge of the ionosphere. Man, I had enough hang time to wander over to the fridge and grab a beer before I landed. So in one sense, yes, Pure is unadulterated fantasy: These sorts of tricks aren't remotely possible under the normal rules of gravity.

But the game isn't completely divorced from reality, either. The control scheme for the ATVs is forgiving, but only so much: You can survive a slightly sloppy landing, but not one that is one notch more careless. And when you first take off from a jump, you have only milliseconds to deduce whether you're going to go high enough to pull off a lengthy stunt. The upshot is that the physics in Pure encourages you to take crazy risks -- while still requiring you to think carefully about what you're doing.

In essence, the in-game physics cooked up by Pure's designers isn't merely a matter of being realistic or unrealistic. The physics is evocative, creating your worldview within the game, and even metaphoric: When you play Pure, you realize that physics is one of the truly artistic elements of an action title.

For example, think about a highly realistic game, like the first version of Gran Turismo. It became famous for offering what were, for its time, highly lifelike models of cars. They were hard to drive: It actually felt like you were steering a BMW across a muddy track in the hills of Tuscany -- which is, uh, hard to do. Friends of mine would coo over the ability to minutely tweak the performance of their favorite car's engine and feel it reflected in the handling. And they scorned the many lamers (like me) who had trouble controlling such realistic models.

If you liked the game, it was because you liked the world its physics built: a rigorous, unforgiving place.

In contrast, the Tony Hawk skateboard games have always played fast and loose with physics. It's not just that the tricks are goofy -- like when I'd jump off the edge of a movie theater and grind along the edge of a moving bus. No, what I notice when I play Tony Hawk games is more subtle: It's the way that aerial stunts feel completely disconnected from Newtonian reality.

In American Wasteland, when I zoomed off a ramp and pulled a "Christ Air" combo, my body didn't feel propelled by any natural forces of inertia and kinesics. I just needed to get high enough off the ground, and presto, I could do the trick. It didn't really seem to matter whether the vectors of movement logically led to the stunt. This isn't a criticism; on the contrary, that was part of the pleasure of Tony Hawk -- the almost hallucinogenic, dreamland quality of the way you moved around.

So what fascinates me about Pure is how the designers strike a perfect middle ground between these two poles.

As I scream around the muddy tracks, it feels kind of like I'm on Earth -- with semi-normal gravity that affects me, and the objects around me, consistently. But it also feels like I'm simultaneously in some zone of half-realism where the rules bend at just the right moments -- allowing me to land safely from a stunt that by all rights should have broken my legs and wrists. So the upshot is that I'm neither as uptight as when I'm grappling for control of my testy car in Gran Turismo nor as wraithlike as I feel in Tony Hawk.

I sometimes wish a racing title would include DVD-style extras, in which the programmers could explain how they modeled the physics in their worlds. It's one of the more subtle and unsung elements of sheer artistry in gaming.

Or to put it another way: Painters use colors and texture to create moods; authors use words and imagery. But action games? They use physics.

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Clive Thompson is a contributing writer for The New York Times Magazine and a regular contributor to Wired and New York magazines. Look for more of Clive's observations on his blog, collision detection.