Unpacking the VR Design Details of ‘Half-Life: Alyx’ – Inside XR Design


Weapon Details

Speaking of commonly used items… it’s time to talk about guns. There’s plenty of shooting in Alyx, so Valve spent lots of time building detailed and interactive weapons. Again, shooting and reloading is something the player will do hundreds of times in the game, so it’s essential to make sure that this part of the gameplay gets lots of attention in the design.

Alyx doesn’t necessarily do anything with weapons that hasn’t been seen in other games, but it nails all of the basics… and stands as the perfect bar for how weapons should work and feel in VR if a developer wants their weapons to have a realistic feel.

So… first thing’s first… each weapon has a unique in-world ammo counter. The pistol has a segmented indicator, the shotgun has a small numeric indicator, and the Combine SMG has a radial indicator. Instead of a floating number next to the gun, these diegetic details encourage players to become intimately familiar with their weapons.


Alyx also gets bullet chambering correct, which gives each weapon an opportunity for a feeling of player ‘mastery’ when they understand how it works.

This is a small detail that’s part of how real weapons work, and I’m sure many of you already understand chambering, but we all learned about it at some point, so for anyone who doesn’t already know, here’s how it works.

When you load a magazine into the pistol, the first bullet in the magazine needs to be ‘chambered’—or you’ve probably heard someone say ‘cocking the gun’— meaning that it’s removed from the magazine and put in place ready to fire. Now that the bullet has left the magazine, if you remove the magazine, the bullet is still in the gun and ready to fire.

When the gun is completely empty, the chamber stays open so it’s ready to receive a new bullet. But this means that if you put a new magazine into the gun before shooting the last bullet, you don’t need to cock the gun again because it’s already primed and ready to go.

And if you look at the visuals and even more importantly—listen to the sounds—it’s clear that Valve wanted to subtly convey all of this to the player.

Note: unmute the clip below to hear the sounds

First is the chambering sound so we know the gun is ready to shoot. Then you’ll hear a unique sound when your magazine is empty but the final round is still chambered. If you shoot again, you get a different sound and even lights which tell you that the gun is now completely empty and the chamber has been left open.

So that little opportunity for weapon mastery that I mentioned is for players to listen for that second-to-last shot—that is the ideal moment to reload, because it means you can put a new magazine in without needing to cock the gun again.

The same thing is true for the shotgun… it doesn’t have an ejectable magazine, but the cartridges still need to be chambered. If you shoot all of the rounds before reloading, you’ll need to cock the gun again. But if you reload on your very last shot… then you don’t need to cock the gun.

Combine SMG Reload

The combine SMG, on the other hand, doesn’t have a chambering sequence because it operates purely on sci-fi space magic.

And Valve, this is the one place where I’m gonna call you out… in this particular video. When reloading the SMG, I really want to insert the mag and then rip off that other part with a nice, satisfying sound, rather than see it just fall out of my hand to the ground. It’s just begging for that interaction.

In any case, the bullet chambering is a clever detail because many players will just shoot their weapons until completely empty and then put in a new magazine and cock the gun every time—and functionally that works fine. But those who get really familiar with what their weapon looks and sounds like can pick up on this little shortcut that saves you one extra step in the midst of combat.

Shotgun Reload

While we’re talking about reloading, it’s worth pointing out another little detail with how the game treats shotgun reloading.

If you’ve played shooters then you know the common tradeoff with a shotgun is that it’s slower to reload since it doesn’t have a separate magazine. That’s true in Alyx too, which gives the weapon some character, but Valve wanted to balance that realism with the time and effort that it takes to reload the gun.

The shotgun holds seven cartridges, which means that reloading it from completely empty would require the player to reach over their shoulder and insert a cartridge each time… 1, 2, 3, 4, 5, 6, 7. That’s a lot of repetitive movement.

Valve smartly cut’s the reload time in half by having Alyx pull out two shells every time the player reaches for their ammo.

So a full reload happens in four gestures instead of seven… but the player still gets seven rounds. And another tiny detail is that if the shotgun only has room for one more cartridge—or the player only has one cartridge left—Alyx only pulls out a single shell.

And last but not least, when you put that last cartridge into the shotgun it makes a unique noise to let you know that it’s fully reloaded.

People Love Plants

Ok, did I talk enough about guns yet? Let’s talk about something happier. Plants. People. love. Plants. And people also love touching plants.

If you put a plant in a VR game within someone’s reach, they will try to touch it. This is just a fact that we all must accept.

Valve clearly understood this, as the zoo level is absolutely full of plants and you can touch them all. Not only do they react to your touch, which preserves immersion, but they also react to explosions which further makes them feel like they’re responding realistically.

Interestingly this reaction to the player also extends to the game’s alien flora, which reacts to your proximity either with lights or bulging or sometimes… jiggling…

More Than Hands-on

And speaking of touching things that VR players will always want to touch… did you know that it’s actually illegal to put a piano that can’t be played in a VR game? Pretty sure that’s part of the Geneva Conventions…?

I’d be willing to bet that most players, actually, know that the piano in Half-Life: Alyx is playable—it’s kind of set up for you to discover that. But did you know it’s also playable with other objects including your gun? And yes, you can even shoot the keys.

But this point isn’t just about the piano. In Alyx, almost anything you can touch with your hand you can also touch with your weapons.

This seems like a minor detail, but like I talked about in episode #1, with enough time things that we hold start to feel like part of our own body, spatially speaking. We slowly gain an innate sense for where the tool starts and stops so we don’t bang it into the world around us (or into ourselves).

And like I talked about in episode #3, touching the virtual world not with our own hands but something inanimate that’s in our hands, works a bit like an immersion insulator by visually explaining why we can’t feel the things we’re touching.

Having the game reflect this reality—that the thing in our hand is an extension of ourselves—adds a certain realism that’s hard to define. It’s those moments where you don’t even think about it consciously… it just seems like a natural thing to use your gun to push open a door or swat an object out of the way.

Compared to having the weapon clip through objects and walls, like we see in many VR games, this little detail helps maintain the lie that the headset feeds to our eyes.

Vodka Bottles

And last but not least… these vodka bottles. The liquid inside is reactive to your movement which makes it feel that much more real. And yes, this effect has been done in games before and since Half-Life: Alyx, but none have done them this well.

The liquid interacts with light, and even makes little bubbles when shaken up. It’s sort of mesmerizing.

– – — – –

Now a quick note before we wrap up. Half-Life: Alyx is an amazing game, and it’s so cool to see all these little details and the thinking that went into them. But I want to make sure we all understand that while it would be awesome to see this intricate level of detail in more VR games, the reality is that no VR studio has access to the number of people, the timeline, or the budget, that Valve threw at this game. So, it would be unfair to see it as a failure when other VR games don’t reach this level of detail.

Alyx is a distillation of a million game design decisions, big and small, made by many people over the course of years. And if we look at it as a collection of the best ideas that made it through that gauntlet, we get the benefit of learning in just 15 hours of playtime the smart bits of design that took Valve many years to figure out. That’s a lesson we should all want to take.

If you somehow have yet to play this game, you can and should find Half-Life: Alyx exclusively on SteamVR.

Enjoyed this breakdown? Check out the rest of our Inside XR Design series and our Insights & Artwork series.

And if you’re still reading, how about dropping a comment to let us know which game or app you think we should cover next?


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Ben is the world's most senior professional analyst solely dedicated to the XR industry, having founded Road to VR in 2011—a year before the Oculus Kickstarter sparked a resurgence that led to the modern XR landscape. He has authored more than 3,000 articles chronicling the evolution of the XR industry over more than a decade. With that unique perspective, Ben has been consistently recognized as one of the most influential voices in XR, giving keynotes and joining panel and podcast discussions at key industry events. He is a self-described "journalist and analyst, not evangelist."
  • ViRGiN

    masturbation o’clock about the geniousity of gayben godlike creations that he wasn’t even involved in or ever played himself.

  • g-man

    Great writeup, thanks. Even though I knew most of this it’s been a while since I played and it’s great to be reminded not only of what’s there but how much work went into making Alyx so special. I hope we see more games of this caliber.

    • ViRGiN

      devs could re-release their games under valve logo and be instantly 1000% better in the eyes of the public.

      alyx is a tech demo. instantly forgetabble, and failed to convince even a percent of millions of pc players to get a vr headset.

      • LOL

        Ignorant troll alert!
        Do not feed it.

        • dextrovix

          He is a fiveskin though, and he knows it with an alias like that. He’s harmless, what does Valve or anyone care, he comes across as an angry teenager.

          • ViRGiN

            valve won’t give you $50 steam card for loving them unconditionally.
            enjoy your stoneage era pcvr.

        • ViRGiN

          Ignorant troll alert!!

      • dextrovix

        As “forgetabble” as you living under you little troll cave throwing insults at such a formidable company that cares not what a little turd like you writes on a forum.

        I love it though, please continue, Blackbeard.

        • ViRGiN

          you sound rewarded, mr gayben.

      • Alex de Vienne

        OMG Boy! This game is so good! Just the best VR Game out there! ;-D And now you can play it with steam link on oculus headsets! Good buy Virtual Desktop!

        • ViRGiN

          HL2 with VR mod is a much more interesting game.

          • Alex de Vienne

            Oh you are a real Valve Fan Boy ;-D

          • ViRGiN

            A Real Fan yes, with a real taste.

      • Only thing thats instantly forgettable and fails to convince are your comments.

        • ViRGiN


        • NicoleJsd

          That troll has been infesting comment sections since like forever. For free probably, figure out

  • XRC

    Great article.

    One thing that always bugged me about HLA, the designers got the bicycles wrong. Anyone that is into bicycles will look at the random bicycles littered about (lent against walls, etc .) and know something just doesn’t look right.

    The wheel hubs are much too narrow, causing the bicycle fork and rear stays to also be too narrow in width. Looks really weird, like the bike was squashed flat.

    For reference, modern multi-speed bicycles use 130-135mm width rear hub and 142mm for many disc brake bicycle with through axle.

    • kraeuterbutter

      on the other hand they did a lot of things right with the bike(s)
      you can send it driving, until a few meters it will fall over
      you can lift it and the frontwheel and the handelbare will flip to one side at some moment
      you can hold it on the stem like a real bike and move it that way
      you can turn the wheels with each of your fingers, stop a turning wheel whit finger and so on
      you can bringt it to the roof of the building (before the elevature-sceen) and let it drive down the roof by itself

      you can crank the crank, the pedals

      so many things done very impressive.. i compared it in a video once, with the bike in Counterstrike, level “Italy”
      there you can shoot the bike and it will fall down.. thats it.. not more doable..
      so 100:1 what alyx achived with the bikes

      • Ben Lang

        Wow never knew about this!

        • kraeuterbutter

          tried to post a video – flagged it as spam
          and another post ist “Pending” ? what does that mean ?

          • ViRGiN

            that you’re spamming

          • LOL

            Ignorant troll alert!
            Do not feed it..

          • ViRGiN

            Ignorant troll alert!

          • Ben Lang

            Unfortunately there’s tons of spam and we can’t moderate it all, so there’s no link posting.

  • Man, I love this Inside XR design series!
    HLAlyx is by far, the most detailed and fleshed out VR game ever made. And the better the headsets get, the nicer the game also looks.
    One thing that works incredibly well with the gloves are the controller straps. Without the straps (or in fact the index controllers), it wouldn’t feel the same since sometimes you need to let the controllers go and not hold onto them the whole time. Thats especially true when regaining health at the charging station.

  • kraeuterbutter

    i was most impressed by how the bike handels when you lift it with one hand, with two.. how the handelbar reacts…
    its so much doing what you expect from a real bike..
    its for me the most impressive prop in Alyx

    in the video compared with counter-strike-bicycle..

    besides: its a singlespeed or fixie bike in Alyx; fixies often use 120mm width rear hub
    in my velomobil i had a american classic hub which was also very narrow.. noticed it when i had to replace it and could find any small hub, had to use a normal hub and when building it spoke all the spokes from the inside – still a little to wide but now workable with wheel housing of the velomobil

    • ViRGiN

      okay, cool, when does the real game starts?

  • Dragon Marble

    Great series. We need more of them. While bad designs are always glaring, great designs can be hardly noticeable.

    I especially like the final comment reminding people to keep an open mind and not always regard any deviation from the classics as a failure. Other studios may not have the same resources, and other games may need to compromise on details because they push other boundaries (a more open, dynamic world, for example).

  • Johna

    All these points matter. But isn’t something missing? Like the best and most detailed graphics in vr combined with great optimisation? To me this is the most obvious difference to every other vr game. The size of the gap to other games may vary. But no other vr game is really en par with hl:a here.

    • Ben Lang

      Yes, but I didn’t want to just say what everyone can already see : P

    • kool

      That’s why I like console vr they have to be optimized well or it won’t work.

  • david vincent

    A shame we can’t mod that game, a melee weapon and holsters would be great.

  • Loooooove this kind of articles!

  • psuedonymous

    “While this seems maybe trivial today, let’s remember that Alyx was released almost four years ago(!). The foresight to offer both modalities means that no matter if the player’s first instinct is to touch the menu or use the laser, both choices are equally correct.”
    Funnily enough, that was more of a throwback than prescient! When Touch first came onto the market, poke-the-UI was the initial thing everyone implemented because it seemed obvious. Then everyone switched to the laser-pointer interface because poking a floating UI turned out to be REALLY annoying, as well as physically tiring. With Quest’s hand-tracking the physical aspect is reduced (but not eliminated, for the same reason actual physical user interfaces have armrests and place controls as close as possible to the hands rather than high in front of you) but generally remain as annoying when it comes to menus. The MR push has encouraged playing about with poke-the-floating-thing again, and I expect the exact same physical interface issues will end up curtailing it once more, because neither physics nor ergonomics have changed.

  • ViRGiN

    I love coverage like this about retro VR games!

    • kakek

      It makes me sad that VR had to go back so far that we still haven’t any other game that can hold a candle to it in it’s style ( Immersive FPS ).

      • ViRGiN

        There isn’t any real shooting in this FPS. It’s a walking simulator. As a shooter, it’s a pathetic title with 3 one handed guns.

        • kakek

          4, and I get why they did that, and it works for me.
          Also, made someone that play walking sim try it, and somehow she found there was plenty shooting.

          • ViRGiN

            Yeah, and my grandmother called DK1 hyper-realistic when she tried it out over 10 years ago.

            > 4, and I get why they did that, and it works for me.

            Because it’s one of the most baby-friendly VR games in existence.
            I’m sure you also know why you can’t melee crab with a chair that you can pick up; and I’m sure there is a perfect expla, ekhm, excuse why you collide with everything on the floor, and why the game does not support room scale. Everything has a reason, and valve would never do mistakes.

            I’m sure you also know when the long announced Source 2 kit will be available to make new VR games.

  • STL

    Skyrim VR has this lock-on stage as well. Since 2017.

  • XRC

    @ Ben

    We are heading quickly to the Index launch day (June 28th 2019)…nearly 5 years already and nothing but radio silence from Bellevue.

    Copium fuelled dreams of ‘Deckard’ keep the light burning for some, but for many it seems Valve’s gaze is locked on the Steamdeck, with VR a distant view in the rear mirror.

    If supply chain rumours are to be believed, Index production has now ceased at Goertek in China and Flex in Illinois. HTC are busy producing 2.0 base station manufacturing in Taiwan now they have the licence.

    Would be interested to hear your thoughts….

    • kakek

      I’d say for now, VR is both a distant view in the rear mirror, and a distant view in a potential future.
      They have their vision of what VR can be. And we’ve seen it, it’s Alyx. That game might have failed at single-handedly launching PCVR, but it succeded in showing what VR could be. It WAS the game they wanted to make, and it was great.
      But at the same time they have no choice but to accept that the industry and most gamers weren’t on the same page, and the VR would have to be wireless, all in headset, or nothing.
      So htey put it on the backburner till they could do both. And that will not be for at least 2 more years. Cause technologie isn’t there yet.

      You know, when they mention they are still working on VR, I do believe them. It’s just that in valve workflow, working on it does not implies that they have any timeline or product planned.
      They are working on it the way the worked on a half life game since EP2. That was true, they had team doing prototype, various project that could have been HL3, none of them ever seing the light of day in the end.
      Deckard is in that state. It’s in limbo. There are people at valve that stick together Amd SOCs and pancake lenses and see how small they can make it, how existing VR games run, and if they could make a mobile headset that run Alyx.
      And possibly at some point they’ll do a prototype they like enough to actualy try to make a product. Or not.

      • ViRGiN

        valve already released codename deckard, it’s called ‘steam link’ and has been published to meta store some months ago.
        they don’t have money nor manpower to work on anything more complex than a DK1 clone with legacy lighthouse tracking. nor they really need to – they aren’t going to have monopoly on VR, like they do with flat gaming, so why even try?

        alyx could already run on quest, if they wanted to do so. there is absolutetly nothing complex about it. you always see so little at once on screen, and there are only few enemies.

        • Ardra Diva

          it’s the realism and atmosphere and attention to little details that makes it special, similar to the assassin’s creed games.

      • Ardra Diva

        A non-issue with steam link now. problem solved.

  • Nevets

    Good piece!

  • Ardra Diva

    Alyx blew my mind the first time i played, when i tossed that can off the balcony and saw it hit a cat sleeping on a chair on a lower balcony and it squawked and ran off. the living world is only a glimpse of what’s to come.