Why “Embodiment” is More Important Than “Immersion”

Our series Inside XR Design examines specific examples of great XR design. Today we’re looking at the game Synapse and exploring the concept of embodiment and what makes it important to VR games.

You can find the complete video below, or continue reading for an adapted text version.

Defining Embodiment

Welcome back to another episode of Inside XR design. Today I’m going to talk about Synapse (2023), a PSVR 2 exclusive game from developer nDreams. But specifically we’re gonna to look at the game through the lens of a concept called embodiment.

So what the hell is embodiment and why am I boring you talking about it rather than just talking about all the cool shooting, and explosions, and smart design in the game? Well, it’s going to help us understand why certain design decisions in Synapse are so effective. So stick with me here for just a minute.

Embodiment is a term I use to describe the feeling of being physically present within a VR experience. Like you’re actually standing there in the world that’s around you.

And now your reasonable response is, “but don’t we already use the word immersion for that?”

Well colloquially people certainly do, but I want to make an important distinction between ‘immersion’ and ‘embodiment’.

‘Immersion’, for the purposes of our discussion, is when something has your complete attention. We all agree that a movie can be immersive, right? When the story or action is so engrossing it’s almost like nothing outside of the theater even exists at that moment. But has even the most immersive movie you’ve ever seen made you think you were physically inside the movie? Certainly not.

And that’s where ’embodiment’ comes in. For the sake of specificity, I’m defining immersion as being about attention. On the other hand, embodiment is about your sense of physical presence and how it relates to the world around you.

So I think it’s important to recognize that all VR games get immersion for free. By literally taking over your vision and hearing, for the most part they automatically have your full attention. You are immersed the second you put on a headset.

But some VR games manage to push us one step further. They don’t just have our attention, they make us feel like our whole body has been transported into the virtual world. Like you’d actually feel things in the game if you reached out and touched them.

Ok, so immersion is attention and embodiment is the feeling of actually being there.

And to be clear, embodiment isn’t a binary thing. It’s a spectrum. Some VR games are slightly embodying, while others are very embodying. But what makes the difference?

That’s exactly what we’re going to talk about with Synapse.

Cover You Can Feel

At first glance, Synapse might look like a pretty common VR shooter, but there are several really intentional design decisions that drive a strong sense of embodiment. The first thing I want to talk about is the cover system.

Every VR shooter has cover. You can walk behind a wall and it will block shots for you. But beyond that, the wall doesn’t really physically relate to your actual body because you never actively engage with it. It’s just a stationary object.

But Synapse makes walls and other cover interactive by letting you grab it with your hand and pull your body in and out of cover. This feels really natural and works great for the gameplay.

And because you’re physically moving yourself in relation to the wall—instead of just strafing back and forth with a thumbstick—the wall starts to feel more real. Specifically, it feels more real because when you grab the wall and use it as an anchor from which to move, it’s subconsciously becoming part of your proprioceptive model.

Understanding Proprioception

Let’s take a second here to explain proprioception because it’s a term that comes up a lot when we’re talking about tricking our bodies into thinking we’re somewhere else.

The clearest example I’ve ever seen of proprioception in action is this clip. And listen, I never thought I’d be showing you a cat clip in this series, but here we are. Watch closely as the cat approaches the table… without really thinking about it, it effortlessly moves its ear out of the way just at the right time.

This is proprioception at work. It’s your body’s model of where it is in relation to the things around you. In order for the cat to know exactly when and where to move its ear to avoid the table without even looking at it, it has to have some innate sense of the space its ear occupies and how that relates to the space the table occupies.

In the case of the cover system in Synapse, you intuitively understand that ‘when I grab this wall and move my hand to the right, my body will move to the left’.

So rather than just being a ‘thing that you see’ walls become something more than that. They become relevant to you in a more meaningful way, because you can directly engage with them to influence the position of your body. In doing so, your mind starts to pay more attention to where the walls are in relation to your body. They start to feel more real. And by extension, your own body starts to feel more present in the simulation… you feel more ‘embodied’.

Mags Out

And walls in Synapse can actually be used for more than cover. You can also use them to push magazines into your weapon.

Backing away from embodiment for just a second—this is such a cool design detail. In Inside XR Design #4 I spent a long time talking about the realistic weapon model in Half-Life: Alyx (2020). But Synapse is a run-and-gun game so the developers took a totally different approach and landed on a reloading system that’s fast paced but still engaging.

Instead of making players mess with inventory and chambering, the magazines in this game just pop out and float there. To reload, just slide them back into the weapon. It might seem silly, but it works in the game’s sci-fi context and reduces reloading complexity while maintaining much of the fun and game flow that comes with it.

And now we can see how this pairs so beautifully with the cover game’s cover system.

The game’s cover system takes one of your hands to use. So how can you reload? Pushing your magazine against the wall to reload your gun is the perfect solution to allow players to use both systems at the same time.

But guess what? This isn’t just a really clever design, it’s yet another way that you can engage with the wall—as if it’s actually there in front of you. You need to know if your arm is close enough to the wall if you’re going to use it to reload. So again, your brain starts to incorporate walls and their proximity into your proprioceptive model. You start to truly sense the space between your body and the wall.

So both of these things—being able to use walls to pull yourself in and out of cover, and being able to use walls to push a magazine into your gun—make walls feel more real because you interact with them up close and in a meaningful way.

And here’s the thing. When the world around you starts to feel more real, you start to feel more convinced that you’re actually standing inside of it. That’s embodiment. And let’s remember: virtual worlds are always ‘immersive’ because they necessarily have our full attention. But embodiment goes beyond what we see—it’s about what we feel.

And when it comes to reaching out and touching the world… Synapse takes things to a whole new level with its incredible telekinesis system.