How Destiny 2 works

destiny-2

This is The Mechanic, where Alex Wiltshire invites developers to discuss the difficult journeys they’ve taken to make their games. This time, Destiny 2 [official site].

When you go down to Destiny 2’s European Dead Zone, you’ll blast your way through crowds of the Fallen and run past other players. Perhaps you’ll also have a friend by your side as you stumble across Public Events and start Adventures, the action naturally flowing as you freely explore. Of course you do! Destiny 2 is an online shooter, and online shooters do this kind of thing.

But the years of work that went into creating the technology that runs it proves that Destiny 2 is no ordinary shooter. It’s product of Bungie’s ambition to meld the rich social bustle and scale of the MMO with the twitch-precision of the FPS, and, frankly, it seems a miracle that it works at all. Destiny 2’s PvE multiplayer is a crazy and surprising melding of design and technology, and this is how it works.

So as you’re running around the EDZ, little do you know it but every few minutes you’re migrating between matches consisting of up to nine players. “It’s almost never something that players see, but it’s a pretty complicated thing happening under the hood,” says Justin Truman, who as an engineering lead and design director has spent the past eight years helping to build the architecture on which the Destiny series runs.

Each of these matches is situated in a distinct space in the world. If you’re a Destiny player, you’ll immediately recognise them: they’re the rooms and open spaces in which you play, and Bungie calls them bubbles or zones. They’re joined together by transitional corridors, caverns and ravines, which each feature a little kink so you can’t see through them from one zone to the next. And it’s in these transitional spaces that the magic happens.

The reason why Destiny 2’s worlds are split into these ‘autonomous units of matchmaking’, as Truman puts them, rather than simply taking place in open areas like any MMO, is down to Bungie’s original goals for the first Destiny. They wanted to make a great action game with the immediacy of a singleplayer shooter. They wanted you to constantly bump into other players. They wanted you to always be able to play with your friends. And they wanted all the matchmaking to happen seamlessly and in the background so you never think about it.

MMOs can generally accomplish a lot of those goals, but they can’t run with the high-fidelity responsiveness and detail of a Halo or COD. And Halo or COD can’t seamlessly allow you to traverse large worlds with lots of other players. “It was a big design challenge and we didn’t know exactly how it should work, and we also didn’t know what tech would enable it,” Truman says. “It was an exciting process.”

As an example of what the team grappled with in the early days of planning Destiny, one of the early ideas was to put a bubble around each player that they’d matchmake into. But that immediately invited questions: what you do with line of sight if someone’s really far away? Can you see them? Are they in some other matchmaking field?

They settled on zones, but the big challenge was how players would be transported between them. The answer was to do a lot of predicting. When you’re running through a zone, Destiny 2 tries to figure out what zone you’re about to go to, and when you start to get close to its transition space, that corridor between zones, the game starts to silently spin up the matchmaking process. You might still be fighting – you might even end up running the other way – but Destiny 2 wants to be ready for when you enter the transition so you’ll be able to smoothly exit it into a new zone, with new players.

“If you start booking it through that transition to the next zone, we have a drop-dead point in the middle where you can’t see the new zone yet, a physical line in the world where we have to have decided what zone you’re transitioning into,” says Truman. “We wait until pretty close to that point to see if we can find a match, and if we can’t, we abort and we let the server spin up a brand-new zone for you.”

And if you’re even faster than that, usually only possible when you’re going full-speed on a Sparrow hover bike, that’s when the whole world can freeze for a few seconds. It’s because the server hasn’t had time to complete setting up your new zone before you need it.

Though it happens behind the scenes and you’re largely unaware of it, Destiny 2’s PvE matchmaking is more complicated than most other games. Part of the reason is that the game is both being hosted on a host player’s PC, which is running the close simulation of the gunplay and physics in the zone, and also on the game’s servers, which is running the broader picture, running events and scripting.

The other part of the reason is that the game always leaves space for other members of your party, or in Destiny-words, Fireteam. It doesn’t matter where everyone is across the world, the game always ensures you’ll be together when you’re occupying the same space.

“But you’ll see if you run side-by-side through a transition with a Fireteam mate, you’ll see them briefly disappearing and then spawning back in,” says Truman. In this moment, the artifice shows, a moment that reveals what’s really happening when you play Destiny 2. When you cross the threshold between your previous zone and migrate into a new one, the game running on your PC has to re-instantiate every object, including your friend, causing them to briefly blink out of existence.

destiny-2-pc-issues

“There are little artefacts that you can see, but I feel pretty good about where we landed, about how much we polished it for your local experience,” says Truman. “But one thing we really worried about and debated is what those transitions would do to the pacing of the game.” When you’re in a transition between zones, the game can’t give you anything to do, like a chest to open or enemies to shoot. All you can really do is to continue running forward.

When they were making the first Destiny game, which works the same way, the team wondered if players would find it weird to experience three minutes of free-wheeling action in a zone and then 20 seconds of silence, followed by another three minutes of action and 20 seconds of silence.

Some of the quiet is covered by the game playing dialogue, but ultimately the pacing simply feels like Destiny. “You can have an intense encounter and then the transition feels like a palate cleanser,” says Truman. “It’s one of those things where you have an idea for what you want the game to be and then you build a bunch of systems and technology that achieves your vision, and then after a while you’ve made enough decisions that the tail is wagging the dog. I don’t mean that in a bad way; we get to a place where the decisions you made define what Destiny is.”

Not all zones are alike. Some are public, featuring strangers running around, while others are private, so the only other players will be members of your Fireteam. “I feel like all the interesting design decisions are about the tension between two different things that you really want,” Truman says. Destiny 2’s design team wanted intense and tightly scripted action for a party to play through, and they also wanted lots of other players running around, but the two desires don’t exactly mesh well, because reserving matchmaking slots for the party means that the game can’t leave space for strangers, and having lots of strangers shooting aliens will interfere with scripted encounters.

Destiny 2’s solution is to divide the world into spaces which are focused on one or the other of these ideals, so as you run from one side of it to the other, you’ll experience both. ”In a private space we can use exactly the right music and have a jump scare and the boss can show up and take four minutes to kill; you can craft all of that and tune the difficulty, whereas in a public space you might show up and someone else has already summoned the boss and he’s at 20% health with six players hammering on it so it’s really easy. That’s cool, because it creates the immersion of social events and mechanics, but it’s a different type of cool than the canned, designed experience.”

That tension hints at other challenges in creating open spaces for strangers to play together. Destiny 2’s zones can handle up to 30 AI and aim for six players, but can go up to nine (“After that you start running out of memory and objects start disappearing from the world and stuff like that”). But while 30 AI sounds like a lot, it can feel sparse when scattered across some of Destiny 2’s zones, especially in the EDZ, which features the biggest in the game.

“We can make a space feel more dense by paying attention to where the player is and then spawn AI near them so there might be 100 possible AI but there are always 30 in front of you,” says Truman. “That works great if you’re the only person in the bubble, but if there are other strangers there there might be someone all the way in the opposite corner of the bubble, taking up most of the AI.”

Truman says that over time, the team has largely fixed this issue, but it can still happen if a player should trigger an Adventure, a scripted event which takes place in public areas, at the same time as a Public Event kicks off, during which waves of enemies and a boss appear. “So if you’re standing somewhere else, you’re probably not seeing any enemies.” One of the key solutions is social: the game calls out where the event’s happening in the hope that players will gravitate towards it, since it’s where the exciting stuff is.

Solutions like this go hand-in-hand with the high technology that runs Destiny 2. Even its most complex engineering achievements are inseparable from design, the soft stuff that makes the hard architecture that Truman and his team built make sense. It helps a set of smartly configured multiplayer rooms coalesce into a world.

17 Comments

  1. mitrovarr says:

    Wow, I had no idea any of this was going on. The planets all feel pretty seamless.

  2. Inspector Gesicht says:

    Destiny 2 the PC Port is incredible. Destiny 2 the Actual Game is uuuuuuhhhhhhhhh…

  3. Stevostin says:

    How Destiny 2 works: not great.

  4. Chem says:

    That’s pretty cool and a cute way to do it. What corridor loads me into a fun game?

    • mitrovarr says:

      I get that Destiny 2 is a game the internet decided they had to hate, and for pretty legitimate reasons… but have you actually played it? I got it in the monthly bundle and I’ve been having a lot of fun with it.

      • Taintslapper says:

        I own it and it is fun for a while, but it suddenly becomes very very repetitive with little to no payoff. Repetitive grinding is fine as long as there is a chance to maybe get something new or rare out of it that’s worth having.

        • Jabberslops says:

          This is almost the same as my experience. I got Destiny 2 in the humble monthly and played it off and on for about a week just messing about doing like 10 “heroic” events and “story” missions. In less than 11 hours of total played time I hit max level without the expansions and had barely even touched the story and side story missions. It honestly felt like I had no where to go from there despite only having around 180 “power”. Of the story missions I have played I’d say it’s taken me about 3 hours to complete them and still have whatever comes after Io.

          Revolvers, Scout rifles and Sniper rifles are pretty much the only guns worth using.

          • mitrovarr says:

            The leveling system is pretty token. The equipment grind is the actual progression system.

            Also, that doesn’t reflect my experience with weapons at all. Assault rifles and pulse rifles are great, the only really bad normal weapons are sidearms (and some people even like those). And nearly every kind of power weapon has advocates.

            I mean my standard PVE build uses a assault rifle, a SMG, and a shotgun.

  5. Mungrul says:

    Same here!
    I even bought the expansions after finding I really liked it. And yeah, while The Curse of Osiris is a little short on content, I’ve really enjoyed Warmind, and together they add quite a bit to the game.

    Things wot I like:
    The shooting and movement. Many games over the years have tried to blend action and MMO gameplay elements, but this is the best example I’ve played. It’s a proper shooter! And floating about as a space wizard is ace fun!

    The strikes:
    It took me a while to buck up the courage to jump in to the strikes, thinking my relative inexperience would be a disadvantage. But thanks to how the game locks off person-to-person communication until you really want to speak to others, and in addition due to how well the game communicates game objectives through various skillfully implemented prompts, I needn’t have worried. And the heroic strikes with their added modifiers have been some of the best co-op experiences I’ve had recently, all without uttering a word!

    Similarly, while I’m not the biggest fan of competetive PvP these days, thanks to the opt-in communication I’ve even enjoyed that, and not done too shabbily! Unlike other games bogged down by levelling systems and other MMO trappings, this even seems pretty well balanced, with gear merely offering options rather than serious power advantages. I’m sure long-time players will say otherwise, but compared to The Division’s PvP where it’s easy to get trounced by someone at a higher power level, this is a delight.

    The world building:
    Yes, while the central narrative isn’t the best (but it’s by no means the worst I’ve experienced), the surrounding lore is pretty good! Yes, I’ve not dived massively in to it, but wondering how all the planets in the solar system that you can visit became inhabitable is pretty cool, with hints delivered osmotically through gameplay.

    The enemies:
    Okay, there could be a bit more variety, but the 4 races you fight are all distinctive and fun to fight. They make use of cover, dodge, flank, throw grenades to flush you out of cover, use jet-packs or alternatives to get to higher ground, all sorts of good stuff.

    The weapon upgrade system:
    Yes, while the game turns into a long-winded power-level grind for the end game, being able to use weapons with higher power levels to upgrade your existing guns is fab! I got lucky and had a Graviton Lance drop fairly early on, and I’ve been able to keep it upgraded as I levelled. This is positively revolutionary compared to most MMO-alikes out there!

    I will admit to trepidation over the pricing scheme for the recently announced Forsaken and Year 2 pass, and that they’re introducing random-rolls for weapon stats reeks of pandering to a loud and obnoxious hardcore.

    But overall, the game’s been a revelation, and certainly made me re-evaluate my opinion of Bungie, who I’d resented since they abandoned the PC and Mac markets and sold out to Microsoft.

    Destiny 2 is a good game!

    • Mungrul says:

      Dagnabbit, that was supposed to be a reply to mitrovarr. Stoopid comment system >:E

    • Jack Kerras says:

      Since you have some interest in Destiny lore: go and read the Books of Sorrow.

      They came out during the Oryx cycle and they turned dumb boring space-zombies into a crazy interesting new thing through sheer force of context.

      I rarely give a shit about story stuff, but Destiny’s lore as a whole package is excellent.

  6. Voldenuit says:

    950 hrs in Des2ny, and I have no idea how it works or what it wants to be. It’s a beautiful mess, sometimes, but it’s always a mess. Buyer beware.

  7. Voldenuit says:

    LOL @ Dev describing their PVE instancing as ‘polished’. The phrase ‘spit and polish’ immediately springs to mind, except with more spit and less polish.

  8. scatterbrainless says:

    This really makes me wish there was a seamless, overworld Titanfall 2 MMO that ran in a similar fashion.

  9. DatonKallandor says:

    If only their matchmaking tech actually worked and didn’t need an absurd amount of upload and played nice with multiple connections from the same IP.

    It’s a lot of tech fuzz for little gain (‘smooth’ transition between tiny rooms) with a whole boatload of issues.

  10. Romeric says:

    My group/fireteam noticed we would briefly disappear and “respawn” in transitional corridors and (as a software developer myself) I couldn’t decide on a reason as to why it was happening. To find out all this magic is happening behind the scenes is absolutely fascinating. I don’t think it ruins the game to know how it’s working – if anything, it makes it all the more impressive. This is a blend of top-notch engineering and very clever design.

    I literally cannot understand all the negativity in the comments above. To me, this game is just excellent and I’ve had a lot of fun with it. The level of polish is almost obscene – you can tell the team poured a whole lotta love into it.

    Great article – many thanks :-)

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