The Low-Tech AI of Elden Ring

45 points by g0xA52A2A 6 hours ago | 28 comments

This is behaviour trees. What you’re describing is behaviour trees. Edit: I see later you say it isn’t a behaviour tree but this is how a lot of BTs are implemented. They don’t always loop from the root. A lot of the time according to state the root is redefined off of a branch and that sub tree is looped until going further down the tree or even into a different tree. Much like the stack you are describing.

AndrewDucker 1 hour ago | |

The article has been updated in response to this post.

(See the end)

cgh 1 hour ago |

Perhaps this explains why Fromsoft npc quests are easily the most inscrutable in all of gaming. Like, okay Hyetta, have another “grape”, aka eyeball, oh now you’ve moved to the bridge in Liurnia, cool. I’ve exhausted your dialogue but you’re stuck. Oh I have to reload the area and exhaust it again to advance your quest. Okay, cool. Now you’re in a random church and you want a “fingerprint grape”. What?

It’s all part of the Fromsoft experience but man, who writes these things?

vector_spaces 1 hour ago | |

RE who writes these things: I know you're probably referring to code here but on the actual dialogue side, there was a charming interview recently with the person responsible for translating Miyazaki's vision into English. He apparently did all of the writing (dialogue, item descriptions, UI text) for Dark Souls, and split the work with just one other person for all the later games including Elden Ring.

https://youtu.be/vIbKALhzHVc?si=WRAQs77WG2QwVkt5

More topical, I do actually appreciate some of the persistent jankiness like this that hasn't changed since their original games. They experimented with different approaches in DS3, where certain NPCs you encountered would essentially evaporate after you exhausted their dialogue, and they would later materialize back in the hub. I personally hated this -- one element I really enjoyed in the earlier games was this sense that the world doesn't revolve around you. The NPCs feel like rich characters with their own goals and motivations

Having them leave when you're finished talking to them sort of reduced them to utilities, which of course they are ultimately, but the gamefeel suffered a bit from making that more explicit. Don't me wrong though, I love DS3, but I didn't care for that particular change

Anyway, handling NPC progression in this way where the player needs to reload the area is more about navigating a technical limitation than anything else. But like many constraints it conspires with others to produce a certain gamefeel that I enjoy. It would feel a bit less impactful if Hyetta just moved on the instant I exhausted her dialogue -- it's more interesting for me to return and see that she has moved on

Another example of this sort of thing is FromSoft supposedly historically being bad at animating eyes, hence many critical NPCs being blindfolded or with faces hidden by helmets or otherwise obscured. This imagery plays nicely with their other sensibilities around character design and is thematically pretty rich

bee_rider 1 hour ago | |

This post seems to be mostly (although not entirely) concerned with the combat AI. The plot based NPC interactions don’t seem to be very dynamic at all, mostly just a graph with a lot of dead-ends, haha.

tancop 1 hour ago | |

thats game design not something engine related. its been like this since before demons souls, i think it started out way back with the first kings field. its just the way fromsoft do things. everyone knows what to expect from them.

mostlysimilar 1 hour ago | | |

Just to underline your point, Sekiro's NPCs behave in a much more obvious and linear way relative to From's other games, so it's clearly a game design decision and not a technical one.

cgh 22 minutes ago | | |

Yeah, I’ve been playing these games since DS1 (currently on my umpteenth DS3 run as I recover from surgery). The quests never fail to make me laugh.

bigyabai 48 minutes ago | | |

Especially in Elden Ring, it also contributes to the ludonarrative cohesion. Hyetta's quest (no spoilers!) isn't meant to be completed by everyone, her story is a foil to Melina's "default" questline that is mandatory for beating the game. Other characters (eg. Boc, Sellen, Selivus, Thops) also have quests that are easy to start but deliberately obfuscated towards the end.

The JRPG logic is annoying, but From uses it to beg important questions about the game world and the player. Fromsoft characters like Lautrec live in infamy for being so slippery and deliberately misleading.

badsectoracula 48 minutes ago |

The article keeps on mentioning about the performance issues of the decision tree that somehow this approach avoids, but it doesn't seem to actually put any real detais about the why here. Especially considering that:

1. Many scripting languages you'd find in games are implemented by evaluating the syntax tree directly (IIRC WitcherScript in Witcher 2 and 3 is implemented like that)

2. A behavior tree can be "compiled" down to a bytecode VM similar to what some scripting languages use

Though if any of these two approaches makes any difference in performance i'm not sure and i'd expect it'd depend heavily on how exactly they're implemented (my kneejerk reaction would be to expect the VM approach to be faster because parsing a bytecode sequence might be more cache friendly than jumping through pointers, but i also suspect that since game AI scripts/behaviors wont do any real computation themselves and instead 99% of the code would be engine/native calls, any potential benefit would be diminished -- but as i haven't tried to implement the same stuff with a realistic setup using both approaches to compare, i cannot say one or the other for certain).

raincole 1 hour ago |

As a game dev, the fact "AI" as a keyword became totally unusable is quite annoying.

rambojohnson 1 hour ago |

What do you mean by "low-tech AI"? This isn't AI...It's a behavior tree. Calling every decision-making system "AI" is like calling a flowchart a neural network.

What you're describing is a behavior tree: predefined logic, predefined responses, no learning, no inference, no model.

Stop calling everything AI, guys.

tokai 2 hours ago |

Low tech AI? Its sounds like standard game AI. I would really like to hear what the author would deem high tech game AI.

evanjrowley 2 hours ago | |

I know very little about AI and game mechanics, but knowing how early Fromsoft games were (e.g., Kingsfield), a basic AI in Elden Ring is very unsurprising. That's not necessarily a bad thing!

My vote for "high tech game AI" would probably be this old mod for Fallout 4:

>PANPC (Pack Attack NPC Edition) is a unique scripted AI management system for Fallout 4. Rather than treating each enemy as an individual proximity-based reaction agent (basically, a mine with a gun), this system generates social feedback between NPCs belonging to the same or allied factions.

>Enemies factor the overhaul health and success of their “team” into their tactical decisions, adjusting their strategies based on their social and threat awareness. As a result, they will switch between ranged, melee, defensive, and offensive tactics based on their perceptions of team advantage and individual risk.

https://fallout.wiki/wiki/Mod:PANPC_(Pack_Attack:_NPC_Editio...

gchamonlive 1 hour ago | |

F.E.A.R. 2 has the best AI that I can think of. Wonder if it counts as high tech or they just squeezed a lot of juice out of basic techniques