Unsynced: The Last of Us Melee System

[Music] all right I think we're ready to get started hi my name is Anthony Neumann welcome to my talk about the naolia system of the last of us thanks so much for coming we're going to talk about some of the techniques and decisions that went into creating the hand hand fighting system of the last of us it's going to be a pretty broad talk we're going to be talking about some aesthetic stuff some mechanical design and then getting into the nitty-gritty of some script syntax so let's get started first fair warning this talk is rated M for Mature there is quite a bit of violence melee system is a system of choreographed violence so it's kind of unavoidable and talking about it so fair warning also spoiler alert if you haven't played later sections of the last of us I'm going to be showing some of that stuff off so fair warning so before we talk about how we did it let's take a look at what we did let's look at what we shipped so we had melee for two

playable characters being Joel and Ellie we had three different Ally types so bill with his machete Ellie with her switchblade and then test Tommy and Henry which with just their fists we had five enemy types being humans and the four infected classes seven weapons and all of us added up to nearly a thousand individual melee moves and that was just for single-player we had a totally separate melee system for multiplayer pvp and all of this never exceeded a four megabyte memory footprint so this is just a graph visualization of the melee system this is just single-player so as you can see it's pretty large there's a lot of moves it's pretty complex so in my dog we always try to do more with less we try to get a lot done with a really lean and mean team so

let's take a look at who we had working on melee so we had one designer yours truly we had two animators this is Lee Davis who specialized on the technical side of animations and this is Ryan McGarry who specialized more on the cinematic side so facial animations the more cinematic moves we had one programmer Ian Jones who has the brain of ten ordinary programmers and he also do a lot of work on player controls so aiming movement Crouch stuff like that so we really only learned I used like a third of his time I so that was the team about three and a third people to make the system so let's take a look at our overall direction we had two goals that we were trying to hit first we wanted to support the tone we were trying to establish with the Last of Us and build on the world we were trying to create we're gonna mail a gameplay that was brutal and visceral and conveyed the high stakes survival at all costs a

world of the game secondly we we wanted melee to take on a greater role in combat in the world of The Last of Us people aren't making bullets anymore so ammo is much more scarce and so melee becomes a lot more important also with the infected classes who obviously don't use guns melee becomes a lot more important for them as well so there's really two stories I want to tell today the first is the story of design how do we create satisfying mechanics how do we hit the aesthetic tone that we're going for the second story is implementation how are we going to ship this how are we going to get it to fit into memory how are we going to actually do this so let's take a look at design first so when we're talking about design it's not just about mechanics it's also about the look and the feel of the combat what's the tone that you're trying to hit how do you convey an emotion through your combat so

an eye dog the game's story is the spine of all our decisions and that doesn't just mean the plot like the narrative of the story it's also the tone and the genre that the story is trying to establish the Last of Us is a story of human struggle in a harsh cruel world the setting is just a backdrop to a story about humanity the pandemic isn't what's important the infected aren't what's important what's important is how he human beings react into these harsh situations to emphasize this harsh cruel world Mele has to be brutal the world has to be high-stakes and that's what really brings out the human struggles of these characters is the pressure of these high-stakes situations so how do we do that one of the first ways is through creating a sense of impact if you want people to get invested enough in your combat to feel an emotion they have to believe it they have to feel it so let's take a look at some techniques that we use for that so we started out

by looking at a lot of anime reference so this is arguably some of the hardest impacts out there are these MMA knockouts and there's something interesting you'll notice about what's physically happening here which is that most of the velocity of the impact is expressed through the person's head their actual body moves very little comparatively and this serves ironically to make the impact feel much harder but it also makes that people feel heavier you know it gives them a sense of weight that makes them seem more believable there's a problem with using real-world reference all the time which is that real life is incredibly confusing if you've ever watched youtube videos of street fights or MMA fights often it devolves into this you know chaos that's not really going to work for a game so how do you make a fight readable and have a sense of impact at the same time so this is kind of what we settled on notice the the really long pauses on the

windup and on the follow-through of the punches this is what makes these punches seem distinct and readable the actual swing itself is only like 2 or 3 frames and that makes it feel really fast and impactful and then again you can kind of see from the enemy's reaction we were kind of following from the MMA reference of moving the head and the upper shoulder is way more than the rest of his body kind of trying to make him feel a bit heavier another way of creating a sense of impact is with sudden and drastic changes in momentum and these cliffs we lower it down just a bit in these clips you can see there isn't a lot of bounce from the head when it hits the surface let's take a look at this slow motion so what's happening here is that the kinetic energy of the guy's head moving towards the wall or the counter isn't going anywhere like it's the only

way it's on the only place that's going is internally as trauma like all of that energy is transferred completely into his cells and you don't think about this consciously but if you're looking at it you kind of feel it you understand it that that is hurting if he was bouncing off of the surface it would look like WWF or something and it wouldn't be as believable of an impact so earlier I brought up humanity as a concept that's important to the game's story this is true but humanity is also something that makes everything in the game much more affecting it really punches up all the action that you're seeing the humanity that's expressed through the characters makes you empathize with them and when you empathize you feel what is happening to them along with them and that makes the actions seem a lot more impactful and real so we want our fights to come off as life-or-death struggles between real human characters driven by self-preservation so how do we do that one major way we express humanity was

through facial animations so we choreograph the combat systems that there were a lot of opportunities for the camera to get up close to see the faces of these characters as they kind of express their humanities and I personally think this does way more than any amount of blood or gore to make your combat seem impactful and it went a long way into helping us like establish the tone we were trying to go for with the melee combat so our next look-and-feel concept is motivation and I'm not talking about acting like what's my motivation what I mean is make sure that characters have a physical motivation for everything that's happening to them so you'll find as you're creating a melee combat system there's a lot of stuff you want your characters to do to support a mechanic or does make the game more fun you'll need them to be in a particular pose or

you'll need them to be a little bit to the right or to move them around what I'd suggest is to always make sure there's some kind of physical reason for them to be doing the things that they're doing some kind of physical excuse that motivates what they're doing in the game let's take a look at what I'm talking about so this is kind of a counter example of what not to do here we have LED jumping up to stab a guy I love this moves one of my favorites but something just isn't quite right here it's something subtle let's take a look at it a little slower and we'll see what I'm talking about so what's happening you'll notice that the guy's standing up to get stabbed and that's kind of ridiculous why is he like presenting his neck to you in order to be killed that doesn't really make a lot of sense so this is what I'm talking about there's no motivation for him to be doing this this was kind of a necessary evil because this move could either be done from a brick stun which has the guy doubled over or it could be done as a stealth kill in which case the guy would be standing up so there was

kind of no way around this ideally we would have had a different animation that could have handled this a little bit better but it wasn't necessary evil to ship the game let's take a look at a better example so here's an example of moving a character with motivation as you can tell here the enemy is standing facing 90 degrees away from Joel if we slow it down you'll notice that the pop is pretty significant when he pops into the first pose of the reaction animation the thing is that your eye hides it because he's being motivated by the axe through his neck so there's something that gives a physical reason for him to pop into that pose and when you look at it full speed you don't notice the pop at all so this is Joel slamming a guy in the wall we really like these wall moves we wanted them to happen as frequently as possible so we were very generous with the amount of distance that you could be

away from the wall with the guy in order for this move to trigger we look at it from the side you'll see how long that distance actually is that's a pretty gnarly lurch like he's going pretty far the thing is that it's hidden by the fact that joel is pushing the guy forward that joel is like moving around and so your eye interpolates that as it's happening again from the player's perspective it looks fine and you don't notice that it's happened so of course something important to consider is how we're going to frame this action to the player so let's talk about cameras for a little bit the base melee camera in the last of us is a systemic camera that can soph to one side and tries to frame both the attacker and the defender by looking at the midpoint and keeping the defender on-screen so let's take a look at what that looks like you see as I punched the guy the camera moves kind of off to the side framing both characters as I move

around it kind of centers a little bit more on jewel into my normal navigational camera when the camera starts off on the wrong side of the action it slowly orbits around until it's in the correct spot so this was the way we found to frame the action consistently without doing a lot of hand placement of cameras and it was something we found was the smoothest way to frame the engine so for special moves like finishers or grapples we used animated cameras for emphasis and a greater cinematic feel and it's kind of an old technique they've been doing in since Scott of war or maybe earlier but it's great and it works for even more impact we used cut cameras but we only use them for deaths and I'll talk about why so the great thing about deaths is it's shocking the camera cut is really

shocking which synergizes well with the shock of being killed so there's a great synergy there the other thing that's awesome is that cutting the camera is very disorienting but the great thing about using it for deaths is it doesn't matter that the player is disoriented because they're dead so cut cameras are a great thing to kind of really emphasize and punch up a death moment as a bit of trivia the clickers and the camera cut were inspired by the chainsaw guy from Resident Evil 4 which also had a camera cut which really made him a memorable enemy one last and just stupid simple technique is camera shake I know it's easy I know like almost every game with melee and it has it but there's a reason it is awesome you should use it camera shake is great so here is the same combo from before just seems a little flat something's not right and

something's not amped up but just a touch of camera shake on all the impacts and suddenly it just feels way more impactful and way more real so camera shake is great so that's the visual element of the design let's talk for a little bit about mechanics about the design of the actual gameplay so the story of the development of the games melee mechanics had a lot to do with me overcoming some ego issues like any game designer I wanted my part of the game to be amazing to be rich deep and complex I wanted some rock-paper-scissors gameplay I wanted some Yomi in there you know I wanted it to be complex and interesting I wanted melee to be able to stand on its own I wanted there to be encounters where it was just melee and that the combat was satisfying enough and complex enough that it would carry for most of the development on the game we iterated

on block counter and evade we had so many different varieties of these mechanics we had timed counters we had evades we had to evade a particular direction to avoid different attacks a lot of different versions of this idea this was based on the assumption that you know a core element of any melee gameplay is the critical strategic choice between attacking and defending I mean that's something that you just have to have in any melee system don't you this is a some footage from a pre-alpha build of the Last of Us one of the first things that's most apparent is how far away the camera is there's a lot more switching between different enemies as you're fighting and you'll notice that I'm able to evade attacks this one was still had and evade mechanic in the game they also see guys getting into this goofy stance and that was the way to Telegraph to the player that someone was about to do an evade and so there was this rock-paper-scissor gameplay where you were then supposed to

grab him instead of punching him the grab gameplay was also a lot deeper you could throw guys around you could grab them and headbutt them which would stun them and then open them up for an even bigger grab there was a lot of complexity yeah let's take a look at what it was like to fight the infected so this was an early build of the Tilted building and you'll see I can evade these clickers which probably would have been nice in the shift game but and you can see we also had this like goofy kill move that was our way of making the clickers which were supposed to be scary so much more challenging so it took a really really long time to kill them so obviously all of this looks pretty gnarly but maybe we could have polished it you know maybe we could have just iterated a little more and figured out a way to make evade work but there was some intrinsic problems with block and evade that we just couldn't get around the first it was really difficult for us

to find any kind of meaningful challenge so we're very limited on buttons because we're a shooter so if there was gonna be a defense button it could only be one button and so the way you would think to add some challenge to it is with timing the problem that we ran into is that the timing was either trivially easy in which case do I have it at all or it was impossibly difficult there was no like middle ground that we were able to find in our focus tests so that was one problem the other thing is that blocking fights against the camera system that we were trying to put into the game so we wanted the camera to be close and over drilled shoulder because that gives you this feeling of intensity this feeling of you know again empathizing with the humanity of the character if you can block someone you're going to want to see them an attack from off screen is unacceptable if you had the opportunity to defend against it if you don't then it doesn't matter that you couldn't see them because there was nothing that you could do about it anyways so that's why in these builds you saw the camera was so far away because people wanted to see these these enemies the other thing

about that choice between offense and defense is most of the time in single player games that relies on one versus many fighting so if you look at God of War two when they cry these types of games they center around the player fighting a lot of different enemies and figuring out when to attack one person versus defend another person the thing is that combat in the last of us doesn't really support that because of the way the stealth works and the shooting works you very rarely get these one on many fights like Batman or something like that you're most of the time fighting one person maybe two so that also didn't work finally blocking waters down the sense of consequence that we were aiming for in the game you know you saw with the clicker enemies you know the consequence of being nabbed by a clicker is way more significant if you can't block him you know if you're able to defend attacks that kind of waters down the sense of you messed up not a game that's hurting you so it watered that down as finally

we cut the Gordian knot and we cut block this was like kind of a really tricky decision to come to it really required us to throw out a lot of our assumptions about what we were doing with the melee system but it was the best design decision we made the thing is that that choice between offense and defense is critical to a melee game but the last of us is not a melee game it's a shooting crafting stell thing and melee game so and just as kind of an idea how Naughty Dog works we cut block four months before ship so we kind of totally changed our game mechanics pretty late in the game so if you don't have offense and defense how do you create at least some kind of a sense of complexity how do you make it so that the player doesn't feel like they're just mashing buttons we are restricted on buttons because we're a shooter so we didn't have a lot of opportunities for different kinds of inputs in order for you to vary your attacks or anything so one potential

solution that was timing attacks now this is a mechanic that's in Ninja Gaiden and double May Cry where you can attack attack pause and attack and that gives you a different kind of combo or some different move another idea we looked into was charge up attacks where you like hold down square to get a unleash your bigger move so there's this implicit like risk/reward thing that happens there which is kind of cool maybe we could do something with strategic placements so no new buttons but lining up enemies in certain ways or throwing guys into each other or something like that maybe we could get something there the thing is for the last of us these ideas are terrible none of this worked and the reason why is they were all just too complex for the player to keep in their head along with all the other things they need to worry about from stealth to listen mode to crafting to all the other complexities that form the whole blast of us combat so how do we were we able to find good complexities and depth that actually worked so the first rule of thumb was to

avoid any new inputs so any mechanic that we were trying to put in we would have to avoid any kind of complex or intricate input a great way of doing that was using context so what kind of weapon you're holding what kind of enemy class that you're fighting against that was a great source of some death and it was very easy for people to understand another great thing to do is to handshake with other systems so melee is a subsystem of the last of us and a great source of depth was handshaking with other subsystems so for example the Shiv and the Mata modded 2x4 interacted with the crafting system if you could grab guys and take them as a human shield which would then interact with the gunplay system so those worked out another thing to do is to try to create predictive strategy so what this means is some kind of mechanic that doesn't confer an immediate advantage but confers some advantage a little bit further down the line so an example from fighting games would be launchers it's

not the launcher that's important it's the juggle moves that you do after and so setting up this kind of future advantage is something I find players really like and makes them feel clever and finally don't hog mind chair make sure that whatever mechanics you're putting in are something that the player can keep in their head reasonably while they're dealing with all the other stuff they have to deal with in the game so let's take a look at an example so the brick was an example of this in action so it creates a predictive strategy it allows you to grab enemies sets up more powerful moves you can instantly kill a clicker if you have a few by for so it links up with the scavenging and stealth assistance of the game because you can throw it as a distraction you punch in your environment behind them it requires no new buddies you throw it just like any other global and it doesn't require much from the player to understand how to use it so yeah that was the brick so just in general there

were a ton of different mechanics beyond what I've mentioned that we tried to put in the game and we had to be really comfortable with cutting them in the name of simplicity and elegance you're always gonna have some idea that it's your pet idea and just be really comfortable with cutting that and letting go of it in the name of making the game simpler and more accessible always think big picture if you're working on a subsystem remember that you are not the system try to harmonize try to to make your thing fit into the larger hole ideally synergizing with the rest of the game so how does melee fit into multiplayer let's just take a look at a quick clip besides this guy's stunned by a smoke bomb just in the neck trying to flee get nabbed by modded 2x4 and crawling away

my friends on fire and then I get executed so as you can see melee ended up giving our PvP combat a very unique feel it really helped to separate us from other third-person shooters in multiplayer but we had to selectively adapt our mechanics for example there's no hostage taking there's no human shield because that's really not fun for the other guy in multiplayer it's no fun to be dried around there's also no bricks because you can't fool a player as easily as you can fool an enemy AI so instead of using bricks to stun and we use the smoke bomb changes like that but one of the biggest changes was that when you punch someone instead of playing a nice full body animation they play just a flinch now let's take a look at what that looked like so we did that to allow the person on

the receiving end to move around again to keep things fun and fast-paced for both players instead of just the person doing the attacking so obviously there's a downside to this it doesn't look fantastic and it doesn't look as good as our nolan melee combat this is especially apparent when two people are punching each other at the same time which looks gnarly and I'm very sorry about this but it was a necessary evil to make PvP fun is just kind of an unavoidable thing overall though we lose a lot of the cinematic feel we lose a lot of the tones we were trying to create with the game so how do we bring some of that back into multiplayer so the answer is fatal movies so again because we turn it down just a little bit again because the person on the receiving end is being killed it doesn't matter so much that they can't move because they're dead anyways and it doesn't matter also a lot of these moves were a little bit longer and it allowed us to bring in the camera a little bit

close and kind of regain some of the intensity that we lost some multiplayer okay so that's design let's talk about how we actually did it so obviously in constable development memory is crazy important even though we've got a ton of memory on next-gen consoles believe me it's gonna dry up really quickly so you'll always have to worry about memory the memory footprint for the melee system in the last of us was four megabytes this is the same footprint that Drake had for his melee moves in the Uncharted series the thing is that jewel has all these weapons there's the infected he's got the human shield there's just so many more mechanics in melee so we had to be really strategic about how we used our memory so I could go on and on about memory management but these are the basic top level strategies that we use the first is modular loading so this is basically breaking up all of your assets into tiny chunks and then only loading exactly what you need at any given time this is how no I dog in

general is able to make their games without any load screens in them because we are able to kind of be very meticulous about only loading exactly what we need so these were all the animation bundles of in the melee system and there's some pretty logical divides here you might be able to see there's the Elliott versus David fight in there there's horse melee so that makes sense you can kind of split things based on where they are in the game and that's a little bit easier something that's a little bit more subtle is this division so Anam go melee is what Joel could do just by himself so if he's alone in a level and he has a pipe it's him swinging it through the air you know it's basically so that you have animations to play it when you press square even if no one's around and in melee common is anything that requires both Joel and someone else it doesn't matter if it's an infected or he just some other enemy so this is Joel

swinging the pipe through the air and it stops on a body when it hits it and then an MN PC melee is anything that required both Joel and an enemy so when the enemy reacts to the pipe swinging that's an anima and PC mailing so at the start of the swing I'm an animal melee on an impact on drill side I'm an animal a common and then the reaction is in an mm PC Millie so why do we do this we do this because in areas where you're transitioning from human combat into infected combat it absolutely ensures that we're not doubling up on any memory if there's an overlap between those two sections when both types of characters need to be loaded so these were the kinds of strategies we had to do to fit in memory another interesting memory thing is we had both male and female infected in the game and for the they required different animations because their skeletons were slightly different and so not only did we have different animation bundles for the female and

male versions but we had been split out into four for female clicker and male clicker female runner male runner it's that way if you're in a fight with male runners and female clickers you only load exactly what you need again we also used animation streaming the last of us leaned really heavily on streaming the game had a reputation for destroying older ps3's and melee was no difference we've leaned really heavily on it the stealth kill the machete moves the grapples anything that was longer than 80 frames was a candidate for streaming and this was a huge win for memory we were also very strategic about our sample rates so most of the animations in the game are sampled at 10 frames a second except for certain hero combos that you saw very frequently like the fist combo and the pipe combo and those were sampled at 15 frames a second the great thing about streaming is once you're already streaming the animation it doesn't matter how big it is and so we were able to sample those at 30 frames a second which made those moves

look a lot better so let's talk about the implementation of our cameras for a second so for a lot of moves with animated cameras if camera didn't trigger the move would look absolutely terrible so when you're slamming a guy into a wall if the camera doesn't work then the normal in-game camera gets pushed up by collision and it'll be in the characters faces and it'll look awesome awful so and we also needed to make sure that the camera was never behind collision because then you'd see back face polygons and again would look awful so what we had was a system of failsafe cameras so this is the clicker kill and those little locators around them are possible camera locations and you can see the system has chosen the one on the far right so if any of those points are behind collision it'll have a backup and they'll have a backup to the backup and there's seven in this move so that was our way of ensuring that these animated cameras would fire and make the move look good so there are a lot of areas in the game that are very dark and so it's

kind of a tricky issue to make sure that melee was visible when you're in these sections so we had this special flashlight that we use to make sure that things were visible so here we can see the normal flashlight you can see that it's coming from Joel's right shoulder it's one of those clip-on flashlights and it's facing away from him so when he gets killed by the clicker something magical happens we're now sudden how this flashlight is in his face and like how is that happening so four moves like this we would hand author a point for the flashlight to be and we would turn off his shoulder flashlight and turn on this fake melee flashlight and it doesn't cast shadows so it was pretty cheap and so this was our you know kind of hand done solution for hero movies like this one but for more generic moves like this grapple we would just position it behind the actual camera wherever the game camera was because if the camera can see it and the light can see it odds

are you can see it because they're gonna line up so if we take a look at what this looks like in game you can see that the transitions between the normal flashlight and the male a flashlight are relatively seamless and you can consistently see the action so getting two animations to play in sync together is obviously a really important part of making our combat look good so let's take a look at some techniques for them so our system from uncharted was basically it was kind of just like any other scripted animation that two characters would play together it was each move was authored as a pair of animations that would play around a single point and that point was placed in the world and his characters replaced that play those same animations together and that was how we did our sinking every melee move was built as a pair of animations a pair that were always meant to go together so for a lot of reasons we kind of broke away from this system

so as I'm punching this infected or this human they're playing different reaction animations and in the Uncharted paradigm those would have been two distinct pairs of animation the guy was facing away from me that would have been another pair of animations so what we switched to instead is a system where I do attacks and I trigger reactions on the enemy and those reactions play independently from me and so what that meant was we had to move away from a system where both people know about one common point well we moved to instead of the system where each character knows where they expect the other character to be and so what this did was it created like kind of a system of interlocking joints where the attacker would place himself relative to where they expect the defender to be and the defender would place himself or relative to where they expect the attacker to be so we kind of joined them together and sync up nicely there were a lot of other benefits that we didn't expect from splitting up and kind of unthinking these moves the first was it allowed us

to create some new mechanics so again I was talking about flinching before and we were able to bring that to single-player as well to create the runners so this was useful in establishing them as kind of a lighter melee class you're allowed to keep moving around you're allowed to punch them back while they're still punching you and this wouldn't have been possible in the Uncharted paradigm the runner is playing animations but I'm not actually playing animations I'm playing these kind of flinches which was enabled by this new system it also created some solutions to the problem of uneven terrain which had always been a problem for us so you can see here that there's a lack of vertical range to the expected location of the defender and what that allowed us to do is in situations like this where an enemy would be standing on top of one meter cover it would allow us to still be able to do damage to that enemy in our old Uncharted paradigm we would try to author synched animations for every possible situation that could happen which just wasn't feasible in the

last of us this doesn't look as fantastic as the rest of our combat but there's kind of a necessary solution to you know fill in the gaps when we couldn't afford to make a synced animation for everything you can see what this looks like going downhill so again there's like a vertical range here and this guy is able to play independent reactions for me which really helped to generalize our combat and make it work on on weird terrain and in a lot more situations so the whole system was implemented in script so for some of you this is going to be the most interesting part of the talk and for the rest of you it'll be over soon so scripting is awesome I started out as a gameplay scriptor on uncharted 2 I did the wounded cameraman sequence at a lot of the other puzzles so I'm super into scripting it's I think it's great and I really love doing it the great part about script is that it moves work on two designers programmer time is absolutely precious whereas designer time is essentially

worthless so I mean I really like are you gonna ask a designer to hand optimize your assembly code to move more stuff onto the SPU's to win back precious milliseconds until your rendering like your rendering engine is running in frame you're not going to do that you need programmers for that you can move work less intense technical work onto your designers script also gives you faster iteration so there's the classic benefit of not having to recompile the whole executable but what's great about script is it removes the barrier between inspiration and implementation the person with all the crazy ideas is the one actually putting them into the game and there's kind of an emotional thing here where you've got your ego attached to these ideas and you really want to get them in the game and you're the one doing it so odds are they will get in the game instead of having to convince the program relieves please get my feature in and finally all true gangsters know you've got to keep it tech space making a graphical scripting

interface is tempting but it's going to take a ton of your tools programmers time and it's just never going to be as fast or as flexible as a text-based scripting system so I'm going let's let's take a look let's compare work flows between graphical and and text-based interfaces so here we have a graphical scripting interface as you can see it's pretty slow there's a lot of mouse movement and it's just it's just not that fast I'm pretty sure this is kismet but in a text-based interface it's just way faster you get a huge speed increase so let's talk a little bit about the overall architecture of the script so it all starts with attack lists because I'm charted only had one button for melee we wanted a lot of variety we wanted something cool to happen every time you press the button so the structure is built around lists like every time you press square there are all these things

that could happen so in the last of us when you press square this is what happens there's a massive master list and it contains these sub lists like playable le attacks and when you're playable le you use those level specific attacks or if you're in some level like when Joel is wounded he has a different set of attacks there and finally Joel's basic attacks a couple levels further down these are the players pipe attacks and you'll see at the top there's something that says func that's the start func basically what that is is a boolean function where if it returns true everything in the list is allowed to happen so in this case it's checking to see if the player has a pipe and now all these moves are allowed now let's get down to the actual melee move level so a melee move at its core is an animation either one or two animations in this case this is a synced move so there's an attacker and a defender move in its animation each move has a priority so if multiple moves are valid

this is how the system chooses which one should fire so this is based on which move is the most desirable so hits are more desirable than misses finishers are better than hits wall moves are better than finishers that kind of thing and finally each move has a start func just like the lists and this is again a function that if it's true the move is allowed to fire so this move is a synced move so the characters have to be close enough together for it to be valid so this is a raincheck a range check to make sure that they're within 4 meters of each other and finally the event list this is the meet of the move this is what actually happens over the course of the melee move so in this case this move is very simple all it does is deal 5 damage on frame 0 so that's the basic structure of the mail a moves themselves what about the AI and their melee behaviors so when the AI decides to go into melee they have a list of behaviors you can see at the top there's an array of behaviors I'm only

showing one here but they choose from a list just like a player chooses from a list of attacks and what a behavior basically is is third simple it's an enemy running at the player and trying an attack list and as soon as one of those attacks is valid it fires so here you'll see there's a priority just like with the moves and this is where I'm specifying the list of attacks the NPC is allowed to use there's a start func just like lists and attacks but there's also an abort func which tells the NPC hey you shouldn't be doing this anymore either someone else is attacking the player or the situation has changed in some way that that you should stop doing what you're doing let's take a look at an example of how all this works so when you get grappled by enemies your allies will try to come to your rescue here we have Ellie rescuing Joel from a human enemy this is a great way to give a player a feeling of attachment to these characters let's take a look at how this works under the hood so this is Elias rescue behavior the AI scripting is

exactly the same for friendly characters as it is for enemies here's the start funk and so basically what this is doing is it's checking to see hey is the player being grappled is he in one of these grapple like those grapples that I can rescue him from there's also a kind of story consideration here where when you're still with tests it doesn't make sense for Ellie to be rescuing you because she's kind of near she's unsure of herself but once test dies now Ellie is able to use these behaviors so down here there's the abort func first there's like a sanity check like if too much time has passed something's probably wrong so you should abort and if the player has escaped from the move by themselves then this behavior is no longer valid at the bottom you can see the attack list idea which is telling Ellie which rescues she's allowed to use this is one of those moves this is an off-screen version of Ellie's rescued move and you'll notice something interesting about the start funk which is that there's no range check so the reason for

this is we want this move to happen as much as possible and if she's off-screen if you can't see where she is we can cheat her over to the rescue so there's no range check as soon as she decides to use this behavior if she's off-screen she can come in from ten 20 meters away to make this work we also had a blend time of zero so that she just pops into the move and doesn't lerp across the map our other allies have this behavior as well which I think really made them seem dynamic and added like a nice feel to our combat so we script in a proprietary version of Lisp which is a language that allows you to really easily establish syntaxes which are basically like big code macros this allows us to template eyes our million moves since there were lots of moves that fall into distinct categories hits misses finishers you can establish kind of a taxonomy and edit these moves as groups so let's take a look at how this works this is a defined syntax and you can see inside it there's

a fight move definition in there and the way the syntax works is at the top you specify what the inputs of the move are like this is what's going to make each move unique so in this case is a very simple move all it has that's unique is a name and attack animation and a defense animation and you can see how these values are then copied and pasted essentially into the move definition this is what that syntax looks like at the end of the day as you can see it's very compressed it looks very nice and this is kind of the comparison you can see how I specify the input in on the lower right and then that gets copied into the move using the syntax and this isn't just about more readable code or less typing what's great about this is it allows you to make sweeping changes across your system very very easily if you have a bug you can fix it in one place instead of a thousand so let's say I went to this talk and I was like wow camera shake is really great I should add it to my moves and so all I would

have to do is add it to the template and then when I compile my code now it's everywhere now every simple fight move will have camera shake I know this stuff is pretty dry but it was crucial to getting the game done it was like a really essential technique and managing all the moves and all the behaviors that we had it was really really essential so something we got a lot out of is uniting our Mele scripts with our normal scripting language so obviously Naughty Dog is pretty famous for our one-off custom crafted setups so we have a lot of power in our scripting system and we've got a lot of mileage out of hooking the melee system into that power so let's take a look at some examples so when you ship a guy and your shift breaks the blade of the Shiv will actually be embedded in the guy's neck this is my job so let's take a look at how that works so this is a script event which is a special melee event that allows us to hook into the rest of the game scripting system and basically

the embed weapon function is a wrapper function that uses the same functionality that allows us to put flashlights in our character's hands or put joules gas mask on his head and so yeah it was just a really simple thing to do that added a really nice detail some of you may remember this climactic moment from our e3 demo and Evan Wells wanted me to make this move as easy to perform as possible to make it almost automatic so let's take a look at how this works in the shift' game so when you knock a guy down to a knee when you aim your gun you'll automatically aim at his head when you aim at him it transitions him into this begging for your life animation and then you kill any so this NPC knee recover is the move the enemy is in when they get knocked to a knee and you'll see there's this event here allow auto aim and this is something we needed for easy mode to help easy mode players get through certain scripted sequences like the

scenario sequence gives you auto in this part detects when the player is aiming at the head joint of the defender and then transitions them into the begging for their life animation and then you kill them so here's another cool little detail when Joel's melee weapon breaks he'll throw it down to the ground if you see it in slow motion you can kind of see a little better so you kind of seamlessly throwing the handle down to the ground so the crazy thing here is that because it's happening while he's moving around you're not in melee anymore so I can't do that animation as part of the melee system it can't be a melee event because you're not in melee anymore so the way this works is there's this attacker end funk and what this means is if the attacker has left the move for any reason if they've been shot if the moves over naturally if someone else hits them this is like a guaranteed thing to fire so it's like an on exit or something and what this does is it

actually spawns a script process that handles the throwing a weapon down so it's like a fadeaway pass to the rest of the scripting system outside of the melee system so here's that script the drop weapon script it's really simple all it does is it plays a gesture of the player throwing the weapon down it breaks the weapon which causes it to physicalize and fall to the ground and then it just cleans itself up all it does is just remove the script process when it's done so let's take a look at one more example this is from multiplayer so all of these animations are the same and there's nothing implicitly about firing these different weapons that gives them any different behavior their hand scripted to make all these different things happen so here I'm popping the head off and this one I had to script the body charring and the flames on the ground and then finally there was a move I really was hoping we could get into the game but this weapon just didn't make it into the game was just a prototype it's a grenade launcher

sorry mom so let's take a look at that last grenade launcher one so basically what it does is again pretty simple it spawns an explosion at the defender and this is a special explosion that doesn't do any damage to the player because that would suck and then it uses my favorite functions the dismemberment functions to kind of destroy all the limbs and the head of the defender so just a couple of things about what I was talking about in terms of script those of small details are exactly what I'm talking about when I say that it's great to move this work on to the designer programmers don't have time for stuff like that like embedding a ship in a guy's neck it's like a small detail and they have way more important things to do they got to worry about the level heap and and that kind of stuff so moving on to the designers allows you to get these kind of cool ideas into the game cheaply and it allows you to kind

of add a lot of personality into your melee system so if you take an away anything from this talk just remember to design for the overall package make sure your mechanics harmonize with the rest of the game don't be like an amateur drummer playing too loud and drowning out the rest of the band find a way to level yourself off and harmonize with the rest of the systems in the game design good complexity design complexity that doesn't consume too much mind share try to create elegant and simple mechanics that still give you great gameplay I highly recommend implementing your system in script and having a designer implement it I think it's the way to go and seriously camera shake is awesome if you're making a [ __ ] game put it in there so finally I just wanted to throw some thanks I wanted to thank a couple people this is Chris Robbins and Ruben Langdon our awesome stunt actors we worked with quite a few stunt actors but these guys were with us from the beginning and they really helped to shape the melee system Chris was the attacker and Joel and Ruben was the

defender and the infected and these guys were great I wanted to thank the rest of the melee team Lee Davis Ian Jones and Ryan McGarry I also wanted to thank a key Ikram who hooked me up with all these awesome portraits I think this is him from Movember and finally I wanted to thank my fearless leaders Bruce Straley and Neil druckmann for all their guidance and support these guys are a blast to work with and inspire me every day they're great finally there's some other Naughty Dog talks you should go see Rob Drupal talk about art direction at three o'clock max D coffee talking about Ellie and AI buddy AI in the last of us at 4 o'clock and Vivienne ding talking about in-game and cinematic lighting at 5:30 you can hit me up on Twitter on a bad data underscore and yeah that's my talk thank you all for coming and enjoy the rest of the conference [Applause]

I think we got like a couple minutes for questions like I need like five minutes or something for questions just go let that run I'll ask a question okay yeah has gone so with your with the really intimate synchronized animations and you know the interacting with the environment in the walls but which you guys approach to making sure was safe so that people weren't split by doorways or you know I'm not sure I know for example in the in the choke out right did you what you guys do to make sure that the general space that the two characters are safe before you actually love the enemy yeah so what we did is there's I don't know if you if you've been any of our other talks you know we have this well I mean it's a common thing uh navmesh right so we've got knavish on the ground and instead of using collision which had all kinds of problems people would just slide themselves away

from the borders of the navmesh and if we had moves that had like a really large area like the choke out exactly like you're talking about we would just raise that tolerance you know so we would give the the player and the enemy a wider berth so they would slide a little bit further away from it so in some situations it's not ideal you get a little bit of a slide but most of the time you don't notice okay thanks how do you sync the loading of animations with a script that fire them like if this scream is firing an animation or triggering it and it's not loaded yet or is it this quick that looks know it said everything is manually loaded it's like a really full-time job for a little kind of full-time job but it's the responsibility of the level designers it's like a really intricate balancing act of loading stuff and they would just have to know if I have these characters in this level I'm gonna need to load these exact melee bundles okay yep hi could you talk about the process that brought you from this really complicated

system and how you ended up being like there are in cases you know you're just mashing the button to make the thing happen from a design perspective what happened at your company to help you realize that that was the right thing to do you know like how do you get there so yeah I mean so really what happened is we were about to put the game in the hands of the press like people from outside of Naughty Dog we're gonna play the game and talk about it to other people and this just changed everything like it was like okay no more screwing around like let's make this happen and it really it kind of cut the BS you know I mean it really forced me to make decisions that actually worked and actually made the game work well and that was kind of the thing that pushed me to kind of get over or like all the things that I was too attached to of you know I want the system to work this way or something like that and it was kind of a teachable moment for me to really kind of let my ego go off to the side and do what's best for the game yeah thanks anyone else we got like two more

minutes awesome well thank you guys so much for coming I really appreciate it