How Barks Make Videogame NPCs Look Smarter | AI 101

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It doesn't matter how intelligent your videogame AI is if the player doesn't understand it. One of the simplest and most effective ways of communicating intelligence is simply to have it say what it thinks aloud - a concept known in game development as a 'bark'.
That might sound pretty dumb, but you'd be surprised how effective it is in practice.
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For additional viewing, check out these videos from other creators:
- ‪@PeopleMakeGames‬ interview with Supergiant on the dialogue of Hades:
• The System Behind Hade...
Plus check out these ‪@Gdconf‬ talks:
- Elan Ruskin on Fuzzy Pattern Matching for Dialogue:
• AI-driven Dynamic Dial...
- Darren Korb and Greg Kasavin on the dialogue systems of Hades:
• Breathing Life into Gr...
- Jason Gregory on context-aware dialogue in The Last of Us:
www.gdcvault.com/play/1020386...
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Video Chapters
[00:00] Intro
[00:53] Bark Basics
[05:16] Designing for Immersion
[06:50] Barks for NPCs
[10:14] Communicating Game State
[14:38] Simple Dialogue Systems
[18:15] Closing
Music in this episode is by Teknoaxe:
www.teknoaxe.com
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AI and Games is a KZbin series on research and applications of Artificial Intelligence in video games. It's supported through and wouldn't be possible without the wonderful people who support it via Patreon and KZbin memberships.
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[@AIandGames]

Kept wanting to make a 'barking mad' joke in this episode, but I just couldn't figure out how to squeeze it in there...

[@mrkoix2398]

surely, god of war was the perfect fit. In one of Mimir's stories he even says the line!

[@calvinjluther]

I bet that's got you barking mad

[@tylerkenney407]

You didn’t mention Senua’s Sacrifice which has the same characteristics as Atreus in God of War. A travesty!

[@bradbradson4543]

Really great video, that has shown me that barks are one of my most hated pet peeves in triple a games, omg

[@tomsko863]

My favorite bark: "meow" from Stray

[@cluckendip]

Another note on God of War's Atreus - when he feels neglected at a point in the story, he stops giving out his barks during combat to show that he isn't worried about your safety anymore. Also, when shooting special arrows, he just says, "whatever" or something.

[@jcorpac]

It sounds like you could also use the lack of a bark to affect game state. For example, in a stealth game, if one NPC barks but you've already knocked out his partner, then the lack of a reply could put them in a "worried" state.

[@CaroFDoom]

my favourite system of ai barks are the friendly ai in counter strike: condition zero and counter strike: source because they pretend to use the in game voice chat and it's very cute

[@Scrydragon]

Mass Effect 3 -- Campaign and Single player: Bark for when a Banshee arrives on the scene. It's an extremely dangerous and creepy enemy, so it has a correspondingly "loud" and nerve-wracking screech when it enters the scene. When playing multiplayer, you can hear them arrive anywhere on the map, regardless if you're facing in the direction, hiding, etc. Super useful because it's a super dangerous enemy with a one-shot mechanic that otherwise doesn't make noise when moving. Experienced players will know to take them out right away.

[@rockbot1337]

BF3 definitely had a colorful catalogue of barks, I was definitely surprised when I started to hear them in multi-player games

[@MrDanVism]

Watching the video, I was actually thinking Bad Company 2 had the best. The barks added so much to the feeling of chaos and battle, the audio quality alone was 10/10

[@maxima3572]

In TLOU2 I really liked how they used the expectation of Barks against the player once you meet the Cult. Up until that point you've been facing enemies who shout their actions or orders to each other, and react with fear when they see deaths. And then it gets dark and you start getting into wooded areas, and you hear a whistle. At first I thought it was some NPC needing help, but boy was I wrong. They teach you that whistles, and specific ones at that, mean certain things. its intuitive, and plays out exactly like how Ellie is learning it herself. patterns for alert, search, hunt, fire, so on. It's a fascinating play on the Bark system that helps to terrify the player at first before settling into understanding

[@tomsko863]

Thank you for adding the name of each game in the video. It really is a wonderful quality of life feature. Otherwise, some game will show up and my mind will wander to trying to figure it out which one is it instead of focusing on what you are trying to explain. Thank you!

[@skittstuff]

It's worth noting also that humans apparently respond faster to auditory stimuli than to visual ones, so there's another practical use for barks! I love how it makes the characters feel more alive and keys you into what the AI is 'thinking' in that moment. ...On an unrelated note, when I was a kid, I helped my dad with the puzzles while he played the original God of War. Now seeing Atreus help his dad with the puzzles in the new one really warms my heart lol.

[@Tuskbumper]

Going through the video and learning what barking is, do I now have a word to put to what I noticed in Disco Elysium. I dig that game and there are a ton of events that Kim your partner responds to. He'll call you out on things sometimes and it really feels like he's watching you. And the devs at za/um did it in a way that was so clever that most players will come out the game believing that Kim actively judges you by even the littlest actions that you do. Even when this actually isn't the case; as I've found through experimentation. At the end of the game there's a system that keeps notes of type of dialogue that you say. He comments on that. There's a system of who you speak to, he comments on that, there's a system on how much you run. He comments on this as well. It's just interesting to see how much it can all be broken down.

[@munchie_gov]

I want to say insurgency sandstorm has by far my favourite system of barks, its the most immersive out of any game I've played. with how important sound is in that game the barks are such a crucial feature where in co-op PvE mode there is a dedicated "intimidate" voice command in the comma rose to to try to get NPC enemies to give away their location by verbally insulting or challenging them (it even apparently aggros them onto you but im not certain of this). there is a gasmask you can buy for your loadout which ontop of shielding you from poison gas, prevents you from coughing in smoke in order conceal your location. The voice acting (aside from the American Security voice, sorry it's just a bit too silly and overboard for me) is also stellar, the reactions your character gives are different according to proximity to danger and all that good stuff. Huge fan of what they did.

[@Twadfire]

Vermintide make good use of barks too, orienting in the map and giving a lot of feedback in combat (from bots and from enemy actions).

[@SKFthree]

Yea, Vermintide has great barks. If a character gets separated from the group, they will tell the other players. The first character to find the correct path to progress will, to various levels of annoyance, tell the other characters which way to go. If a character is on a kill spree, the other characters will comment on their prowess, and the character in question will sometimes reply. When certain special enemies appear, the characters will shout a warning, etc., etc.. Not to mention the random dialogues characters will have with eachother.

[@sunnyheadcase]

Nice video. It's not often anyone makes a video about Voice Over Design. A discipline that in the grand scheme of things is still relatively new, but also seems to have found a home in nearly every large development studio led project. One little comment mostly nitpicking about semantics of the term "barks" though. There are of course no hard rules when it comes to terms like this, I think generally "barks" is a fairly antiquated term these days in this regard. However, "barks" usually refers to VO that is triggered systematically, and usually in a system that is reused it multiple instances throughout the game. It tends to refer more to VO lines that are reusable. This might be just my opinion, but I think it's relatively shared by most VO designers that scripted, or planned moments that trigger VO that is specific and used only once is something different than barks. "Scripted VO" seems to be a prevailing moniker. But like I said, it's semantics and I appreciate someone highlighting VO as a tool, I don't think it gets enough attention as it is a relative newcomer to game development. It happens to be something I have a lot of experience working with too, if you'd ever like to chat about it further/deeper let me know :)

[@j.j.maverick9252]

yep, the term itself lends to that interpretation. A bark is short noise either pointless or warning (in both contexts: don’t do that vs watch out) The call and response or continuing dialogues should have another descriptor

[@stephanewantiez164]

It can change from one game to another. I worked on Far Cry 5 and 6, and in FC5 we were talking about barks, and in FC6 about systemic/scripted VOs. And now on the game I'm working on, it was dialogue stims, or bark again. ^^ "Dialogue System" tend to be used in Assassin's Creed and other games for conversations between NPCs or with the player, with different levels according to the focus of the player toward the NPC for the latest: DS1 for NPC talking to you but you can still move freely, DS2 when the movement are restreined like in Cyberpunk, DS3 when it's more a cinematic with no control.

[@brettabraham]

Barks are one of those things I keep telling myself I need to include in my games but I always have something "more important" to implement. Definitely need to add them to properly provide feedback to the player.

[@Rusrik]

Another example of barks are the ones used in party-based action-rpgs like, e.g., Tales of and Xenoblade. Your party will (over-)use barks to tell you what kinda skill they use, if they are losing aggro, etc. It can get annoying, but is also a crucial part of the battle system, which helps you to keep track of the state of the battle.

[@phillippi2]

I don't know how much interest the community would have in seeing this as well but, thought I'd propose this: I'd like to see analysis on landmark games of AI. You've already done one on Goldeneye. But, I'd like to see one for an even older game, one that could be said to use a spiritual predecessor to the Goal Oriented Action Planning system. That game is Ultima: Underworld. Ultima: Underworld came out in 1992. It's AI worked based on a series of checks and balances. Those balances are based on the current creatures state; where they are in the environment, how much HP they have, and their emotional state, which is also a balance. When a certain state is achieved, a moral check is performed. That is a "flip of the coin", as it were. If it lands on "heads", the AI deems that it should continue fighting. If it lands on "tails", the AI will stop fighting for a random amount of time and flee.

[@antoniomiller367]

Barks? Oh you mean RAMIREZ...!

[@brianfunt2619]

RAMIREZ... Give me a back rub

[@Strelnikov403]

You could (should!) do a whole video on the guard AI in the Metal Gear games. It's so sophisticated.

[@jacobturnerart]

"Whose footprints are these?!"

[@dreddeus]

Well done, great vid!

[@13thravenpurple94]

Great work 🥳 Thank you 💜

[@Xxnightwalk1]

Awesome video, always instructive Glad to see more AI 101

[@weavelcow9596]

Thinking about Barks, one if the best games I've seen implement them is Vermintide 2. Not only does it have z myriad of barks for specials spawning, items that are around or player conditions. It also has a tone if dialogue that can be triggered by having specific characters present in certain situations or, even in downtime. Pretty impressive all things considered, and it helps that the writing is fantastic.

[@spicydong317]

Problem with the barks is, that usually devs make them sound too comical and cliche It makes it hard to treat enemies seriously because of that

[@AIandGames]

Oh yeah, a lot of it is focus tested into the ground. Sadly a lot of players don't notice this stuff until the NPC straight up yells *"WHAT WAS THAT NOISE!?!?!? IS SOMEONE SNEAKING AROUND OUT HERE!?!?!?!"* .

[@HerrCron]

@@AIandGames Players in general are amazingly oblivious. Apparently, nobody bothers to read the legend of what button does what on bottom right of menu screens, which is why there's been such a shift to having input prompts on UI items themselves in the past half decade or so.

[@MMallon425]

like when a Skyrim bandit catches an arrow in the head and his partner looks around for a minute but eventually gives up and shrugs, "must have been the wind!"

[@IronFudge123]

@@AIandGames When developing Halo, playtesters would be confused by the grunts' panicking behaviour. They eventually had to have them scream "LEADER DEAD, RUN AWAY" for *some* of them to get the memo.

[@stephanewantiez164]

It's a difficult balance to find when you work on barks in a game, especially with the player barks.

[@hershmergersh6733]

Thief still has my favourite barks. "Oi! Who's taffin' around over there!"

[@davidpinkerton303]

Great video! I feel like barks have become a crutch in games to express what an NPC is doing, rather than letting players figure it out. It always bothered me when a stealth game uses a loud audio clue ("What was that noise?") to let you know you triggered an enemy.

[@XiaoNomine]

Oh! Nice to know the proper term for those, as barks are honestly one of the main reasons I heavily prefer playing most games WITH audio. Barks also impact what characters I want to use or partner up with in certain games, as some characters tend toward being more annoying and or sparse in actual information (be it lore or current events) than others in my opinion. Honestly it reminds me of my favorite mod for skyrim as the addition of Inigo adds so much compared to a majority of base and modded companions in my opinion as far as the sheer depth of his comments outside of direct dialogue when not sneaking.

[@matthewboyd8689]

Black Ops 3 zombies had some of the most funny and most story rich conversations that came out of nowhere from this kind of stuff.

[@MyurrDurr]

The bark system in the campaign for Titanfall 2 is really great It lets you know if an enemy has seen you and where you were when they saw you I've never seen a game that goes that in-depth about it before. "Target spotted to my 4 o clock, by the door" or similar

[@SiegmundXD7]

one that comes to mind is from the opening of skyrim where, if you stand near tullius for too long, he goes “Run, you idiot!”

[@jsecurity1887]

I loved the choas of cod 2 barks, I have never heard that again in another call of duty

[@Jonathon_Hennessey]

In Resident Evil 4 when she's been abducted by one of the Ganados, Ashley will scream out help me Leon or Leon help so the player can rescue her before she can be carried away.

[@fluttzkrieg4392]

Someone commented how they don't like certain things enemies say "What was that?" "Never should have come here..." etc. I actually like these more than for example, the almost completely incomprehensible things the Combine in Half Life 2 say. Although for a more serious tone, I think The Last of Us 1 and 2 really hit the mark.

[@dylan.t180]

Fantastic video

[@_kingfish_4158]

thank u for mentioning cod 2 . barely anyone talks about that games ai

[@danando2]

Im suprised metal gear solid isnt shown more or thw focal point of this video, I like how you picked up command and conquer,unit ready x 40 unit lost, unit lost, unable to comply, building in progress, silos needed lol

[@_gamma.]

Nintendogs must have the smartest AI

[@AIandGames]

Woof!

[@AlanZucconi]

Sorry, the Shader Wizard in me just got distracted by those translucent, subsurface scattery crystals at 18:40... 🤩

[@LexieAssassin]

Grunt (Suiciding): "Please enjoy my BRIGHT, BLUE BALLS!"

[@77robertmilton]

“Ramirez, get the f*ck off the roof!”

[@chrisrosenkreuz23]

hey just curious, anyone know how the Winamp shuffle's AI worked? I mean with TENS of thousands of songs in one playlist, it always somehow ended up picking the same songs to play

[@jacobturnerart]

One of the reasons I like Code Vein - sure the AI companion whitters on a bit, but as there's no bark dialogue from mindless enemies in most soulslikes, it made the game seem a less lonely experience.

[@Fachewachewa]

Hadn't considered Ellie's or Atreus' interventions as barks before. From the description and use, isn't it a similar application when characters like Alloy or Nathan Drake talk to themselves? Are these also considered barks, or something else since it's not coming from an NPC?

[@jacobturnerart]

Great examples - Drake especially wouldn't be nearly such a cool character without his little remarks. I'm pretty sure.the early games were largely scripted barks - not sure re the fourth game's more open areas.

[@HarryH256]

Quite a simple one, but Metal Gears ! and accompanying noise is one of my favourite barks.

[@vaidasokunis]

Do you have any plans of uploading your videos to Nebula, this is one of the few channels why I even come to KZbin these days.

[@AIandGames]

Well I appreciate you popping back over here to check out my stuff! 😊 Publishing on Nebula would be pretty cool, but it's completely outside of my control. Creators on Nebula are recommended and invited from within, it's not an open platform. So unless someone who has a channel on Nebula recommends me (or perhaps enough users on Nebula reach out to encourage it), I wouldn't be able to do so.

[@minerkey682]

is it just me or does the NPC at 7:09 sound like Homer Simpson, I cannot get it out of my head

[@PackerB]

The best bark ever for me, is when you shoot a gun out of the hand of an enemy in Perfect Dark and they say "My gun!".

[@kaelside]

Excellent video! Although, you pronounce "Atreus" as if you've only read it and never heard it said out loud 😀

[@AIandGames]

This tracks.

[@vagnerleite3879]

In Castlevania Sotn the Fairy let's you know about puzzles and breakable walls

[@Legion12Centurion]

Barks are a petpeeve of mine, they can also have the opposite effect. If the enemy says they are flanking and telegraph this by actually flanking or they scream reloading and do this it makes them seem dumb. Because it allows the player to anticipate and counter them far to easily. I think this its a balance act but I have actually wanted the industry to mask the AI and what they are doing more. I think an enemy shouting im reloading is really stupid. It was part of the immersion back then but today I think it can be done better. In the sence that enemies shout out locations, enemies, and they act accordingly without revealing the plans like a mustasche twirling bad guy. Im excited what the future of AI brings us and I think you are spot on in the sence of the way these examples have had an effect in the past. I still remember FEAR fondly for its AI and the barks are part of this. But we need some steps up, I feel AI have taken a backseat in the last 5 or more years due to an increase in multiplayer and co-op titles.

[@HerrCron]

Yeah, barks *are* great.

[@darkdagger2287]

13:39

[@YoloMonstaaa]

I'm pretty sure you taught me C# but now i can't find those videos. what happened?

[@nineonine9082]

Hmm was it from cod 4? SAN GRANATA!

[@dashblue8224]

A lot of these ‘barks’ are cutscene type moments that don’t feel unique on a second play through

[@REXanadu]

Do 'barks' exist in games with no spoken dialogue, or am I still not getting this right?

[@stephanewantiez164]

You have also what we call "ono" (onomatopea) which are not spoken lines, but just reaction sound from a character - like "outch" when hurt, etc.

[@Brandon_Y.]

Death to Spies don't have any barks at all. that's how shity their budget is. it sucks trying to sneak or fight in that game

[@The1Overmind]

Hey! Listen!

[@rhysharries7315]

Drives me crazy when people say Atreus is name wrong. Did you not play the game?

[@seth7862]

came here for dog AI info, disappointed :)

[@AIandGames]

Ah clearly you need to watch the Command and Conquer episode. Got some good dog AI content in that one 😉

[@GraveyardTricks]

Quite low quality content with this one