Ever seen a kid playing Mario Kart?

If they’re real small they’ll be mashing buttons at random. But if they’re old enough to get the game you’ll see them start to move with it. They’ll be sticking out their tongue in the direction where they’re driving. Sometimes they’ll move their entire body, trying to affect the game through full body motions.

I get the same effect when I’m a passenger in dad’s car except that I try to press the break pedal. The man’s a speed maniac.

But I digress.

Point is I’ve never seen someone move in tune with a 3D shooter, or an RTS. There are only a few types of games that affect players with enough sensory immersion to make them respond physically to the game. Except that I just lied to you.

The reason is that immersion is only a small part of the sympathetic motion, when people start to move in tune with the game. You need two more components: you need to give players controls analogous to their normal movement, and you need to give them a space through which to move which is analogous to our own.

Let’s unpack that a bit, but before that let’s ask a question: why should we care?

Because physical motion engages motor memory, which in turn increases the reward of playing the game. I’m not talking about game rewards, I’m talking about neurological rewards. The brain is wired to movement. We’re extremely adept at moving, at sensing movement (is that a tiger in those bushes?) and at gaining feedback from our own motion. Don’t believe me? Try this: close your eyes. Then put your left hand in the air somewhere in front of you. Now take your right hand and point to your left hand. Open your eyes.

Unless you’ve got a very rare disease called Ehlers–Danlos syndrome, are suffering from pyridoxine (that’s vitamine B6) poisoning or are stinking drunk, chances are that you’ve managed this. That’s your proprioception (kinesthetic) sense at work. And yes, humans have got a lot more than five senses. Depending on the way you count it’s anything from nine to in excess of 20.

But back to motion. We’ve built to move. We’ve even got special mirror neurons, which are brain cells which let us mimic how others move without having to consciously think about it (Ever notice how you sit or stand in a very similar way to someone you’re talking to? That’s mirror neurons at work.)

So what, we like to move.

More than that, we’re supposed to move. We’ve got an entire memory “channel” devoted to it. That’s why we can type in our pin code without remembering it – muscle memory. And when we play lots of a certain game we move the actions in it from conscious thought (slow) to our reptile brain (fast) (btw, that’s a term for basal ganglia). Ok, now you know enough basic neuroscience.

So, we’ve got our kid, she’s leaning into the turns in Mario Kart, she’s having a great time.

Her muscles are telling her to have a great time.

“What?” you doubters say, “how is that even possible”. See, the neuro-muscular system is built to be self regulating. Basically that means that if your muscles do something they send feedback to your brain telling it that A) hey, we’re doing something and, more importantly B) this is what you as a brain is supposed to think about it.

For example, if you start to smile you will become happier on pure muscle feedback. If you stand in a dominant position (head up, chest forward, arms akimbo – think bad-ass drill sergeant) you will become more confident (and more aggressive). If you lean into the turns you will become more immersed in the game. The game will be more fun because you’re activating your muscles, however little.

See, you don’t need to activate your muscles a lot. It is enough that the mirror neurons fire and you get minimal muscle response. Neural pathways don’t care about the size of the motion, only that the motion is there (that’s not strictly true but for our purposes it is true enough). Moving your head as your character tries to peek around a corner makes you more immersed in the game (which is one reason why the “over the shoulder” cam is so popular as it is a bloody silly way to view the world). And as your mirror neurons get you to move, and your muscles tell your brain that it should be moving, you start to experience a sympathetic connection to the game. You become emotionally closer to your avatar (character, airplane, runaway go cart, whatever it is that you’re controlling).

Back up. I’m not saying that you fall in love with that F-16 Strike Eagle. I’m saying that you will be more engaged on a basic level – fear, tension, stress – with your avatar than if the game doesn’t cause you to move.

Now, sympathetic motion isn’t for every game. It would look quite insane in Chess. But if you’re making a game where motion is central, why not try to achieve a sympathetic link, however weak? If immersion is pleasurable (and it is), why not give the player that pleasure?

So how do we achieve it? As I said at the beginning of this article: you need to create a space which is analogous to our own, and a sense of motion that is analogous to our own. The “and” is crucial here, just a space or motion isn’t enough to get those mirror neurons happy. You need both.

The spatial requirements are easy. If you’re not doing a 2D-platformer you’re likely to have a 3D environment. Voila, instant analogous space.

The motion requirement is tough. You can’t have motion that is too fast or too much outside of our range of motion. Take a look at someone playing a 3D shooter where they’re jumping around and strafing. The space is analogous, the motion is not – how often do you jump 5 meters into the air (that’s 15 feet) or run full tilt ahead while looking off to the side? But slow the motion down (like in, say, Half Life’s horror parts) and you get analogous motion. And that’s where you start to see people move their heads to look around corners in the game.

And then you’ll know that you’ve maxed out your motile immersion.