Hacker News Reader

Comment by LoveMortuus | Hacker News Reader

I long for an RPG where I can have an actual conversation with an NPC. One with persistent memory, you know so that they remember that you murdered everyone in their family and stole everything they own. And not greet you every time like they've never seen you before.

Brutal example, but you get my point. Something that is ever changing.

View on HN

I think you could make really cool games around this too. I think the two main challenges and the reasons that most games don't work this way are:

1. It's often likely not fun. A big part of the joy of games is feeling empowered and free from all of the consequences of our actions in real life. Exerting power is often selfish and if NPCs remembered every single selfish thing you did, it would make playing the game feel as confined as real life. So much of the escapism of games is that freedom from consequences.

2. It's a testing nightmare. Games are essentially a ball of mutable state wrapped in a rendering engine. As any software engineer knows, mutable state is the largest source of bugs. Whenever you increase the amount of state the player can modify, your testing burden goes up significantly, potentially combinatorially. If NPCs remember your interactions, it means they are all carrying some mutable state around that can affect gameplay.

You've opened the door to an absolute testing nightmare where QA will file bugs like, "If you forget to ask Jane about her dog before talking to Fred about Jane, then four levels later you can't get her to tell you about her dog door and it's impossible to sneak in and find the key to finish the game."

I've been reading recently about the Language of Thought Hypothesis and the idea that conscious thought may be a production system. That is, it seems to work like a formal language or rule-based logic where a "sentence" (in the symbolic sense) may be extended or transformed by "rules" to produce new "productions" in theoretically infinite length and variety even if the actual performance thereof is bounded by limits of time and memory.

In contrast it seems almost all game NPC AI's are state-machine based. One could fit this into the framework described above by calling it a degenerate form of production system, where rules can be applied to transform a sentence (or symbol) representing one state into that representing another state, but none of the states are combinatoric and the rules just interact in a directed graph.

I'd like to see a game where, instead of just states in a state-machine, the NPC's could generate thoughts like a production system. Even if it wasn't connected up to complex action or a planner, it would be interesting if the NPC's could have inner lives based on a chain of thinking, like, "Mary loves Joe. Joe loves his dog. Joe's dog eats hot dogs. I wonder from where Joe buys the hot dogs for his dog." Etc. etc.

See: https://plato.stanford.edu/entries/language-thought/#ArguPro...

It's not an RPG and the interface is limited, but may I introduce you to Galatea?

https://ifdb.org/viewgame?id=urxrv27t7qtu52lb (you can play in your browser with the "Play On-line" button.)

Make sure to start with "help".

She gets annoyed at repetition. She'll react to things you do in the room. Responses differ based on prior conversation and some sort of internal mood implementation.

It's a breathtaking amount of work, but it's the very best NPC conversation I've seen.

This is what I loved about Deus Ex, actions had consequences. Too bad it didn't catch on with later games.

Deus Ex only had a few moments with slightly difference based on your actions. The first one is the boss' reaction to your first mission depending on how violent you are in your approach. You get a few lines of praise or a chewing out and the weapons master will issue you some different gear for the next mission. That's about it. Later on, there are smaller difference I think like whether to manage to get the code word to activate a kill switch, whether you save a hostage... but the consequences are fairly minimal and confined each time.

I'm more impressed with the handling of consequences in Mass Effect 1 to 3. If you carry a single save game through all three games, the third game can become drastically different. One member of your party won't survive ME1 (it's your choice who that is) and the other one will substitute for them in ME 2 and 3. You can lose an almost arbitrary set of party members at the end of ME2. ME3 has a set of alternate party members to draw on when the main ones are gone. The fates of multiple NPCs can carry through all three games and end in very different ways (e.g. Karin Chakwas, Conrad Werner, Gianna Parasini). The controversy of the ME3 ending aside, the last entry of the series changes remarkably depending on your earlier decisions. Getting all of this straight must have been an enormous effort.

Mass Effect was still a massive disappointment though. So many choices, but they all converge into the exact same endings instead of diverging into wildly different possibilites. It really only determines how optimized the outcome is, the result is still the same. The only way you can fail is if you literally choose to do so at the very last moment.

Let's be realistic here: there's only so much that you can do on any realistic budget. A more elaborate and variable ending than what the ME series got at the end of ME3 would be a really big undertaking. I believe that the rest of the game would have suffered greatly from reduced resources if ending hadn't been as railroaded as it was. Maybe it's an unpopular opinion, but I got many hours of enjoyable gameplay out the series, so I can forgive an unsatisfying ending.

Deus Ex has a few more examples, like the fates of Paul and Jaime, but each of these things is explicitly scripted based on event flags, which explains why there aren't a whole lot of examples.

Right, I forgot about those! Still, these moments are designed to mostly be self-contained and have little to no interplay with each other. This keeps a nice lid on the complexity of the narrative.

A game's narrative complexity can easily get out of control when impactful player choices are allowed to become combinatorial. Implementing that many different outcomes quickly becomes infeasible.

In the interactive fiction world, where a great deal of effort has been put into complex, responsive storylines, a common structure is the "branch-and-bottleneck" -- allowing a variety of paths through a particular area, but all of the paths bunch back together into a single path at the end, with possibly a few major flags enduring for the rest of the narrative. As this article mentions, enforcing some structure on the narrative like this not only makes implementation easier but also tends to make the story more coherent for the player:

https://heterogenoustasks.wordpress.com/2015/01/26/standard-...

I think this is the case in Gothic IIRC. As soon as you misbehave on some NPC, he will stop to cooperate with you (no more quests, no more trade, no more friendly smalltalk).

Which character do you have to kill to make him cooperative again?

Half joke, since too many RPGs have killing (or something equivalent) as their primary interaction. Geralt of Rivia must have extinguished the wolf population of entire countries, a band of Pokémon trainers would devoid an entire forest of animals to level up their pikachus, etc.

There were games exploring in this direction in the 80s, but they were never sufficiently commercially successful, with the Ultima series being the most successful (and even with that, when Origin released Wing Commander they saw how much more profitable an actually popular game could be).

Perhaps give Trust and Betrayal: The Legacy of Siboot a try. Arguably NLP has reached the point where that game could be remade without the reverse-parser?

Which Ultima games are you thinking about? The series definitely was pioneering in simulation elements (day/night cycles and NPC routines in V, movable objects in VI, stacking and layering in VII), but the dialog system was always pretty simple keyword-based stuff, and NPCs mostly do not have any kind of memory. Are you thinking about how companions in VII will abandon or attack you if you do too many crimes with them around?

You are right that the dialog was simple and the NPCs basically got mind wiped every time you left a region. However, going back at least as far as Ultima IV, for the time within a region if you stole or killed, that actually had some repercussions. AFAICT the lack of persistence was due to technical limitations rather than a design choice.

IV is an interesting case because the entire game was built around repercussions for your specific actions, although the only long-term repercussion of doing comically evil things was that you had to spend a bit more time throwing money at beggars and overpaying at the reagent store.

V switched to a simpler karma system that mostly affected how badly you were penalized by dying and whether you were able to complete the game.

Reputation systems were pretty common in CRPGs starting in the '90s. In practice, though, a lot of those systems just boiled down to "does everyone in town want to kill you the moment they see you or not".

I think my original point that I made poorly was that in, say 1987 one would see that games were exploring the possibilities of the sorts of thing that the original commenter was hoping to see, but were held back by limitations of the hardware.

What we ended up with was 2-9 factions with up to 3 levels of response (hostile, neutral, friendly) which would be a disappoint to an optimistic CRPG player from the late 80s.

or a pokemon that you actually "train" like you would a real animal, following all the principles of animal reinforcement (which you sort of get for free with neural nets)

I think black and white had that.

did not know, nintendo should take inspiration here

Black & White, a video game from Peter Molyneux in the early 2000s, had this. Unfortunately, the sequel simplified it to a set of slider bars, the company went under, and now Molyneux is focusing on NFTs and other scams.

The Creatures trilogy also had some pretty advanced AI, based on neural nets. They're pretty small by today's standards, but the paper below does a fantastic job of explaining how they are trained while minimizing the computational time.

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.18...

that is absolutely fascinating. curious to read the paper, and see what the major obstacles were, or whether some newer techniques (like federated learning) could make the process more computationally efficient

I remember training your creature quite well. Teaching it to play "catch" with a boulder led to some interesting results, including:

- You were supposed to pet a creature if he did something correctly. Unfortunately, that same behavior also encouraged him to eat whatever he was holding. So I pet him after he caught a boulder, which then made him eat the boulder.

now that is seriously amazing gameplay mechanics

Fun(?) fact: Demis Hassabis (CEO of DeepMind) was the lead AI programmer for Black & White.

More than Black & White and Fable, it was the Creatures series that was designed around this ide:

Gameplay focuses on raising alien creatures known as Norns, teaching them to survive, helping them explore their world, defending them against other species, and breeding them. Words can be taught to creatures by a learning computer (for verbs) or by repeating the name of the object while the creature is looking at it. After a creature understands language, the player can instruct their creature by typing in instructions, which the creature may choose to obey.

A complete life cycle is modelled for the creatures – childhood, adolescence, adulthood, and senescence, each with their own particular needs. The gameplay is designed to foster an emotional bond between the player and their creatures. Rather than taking a scripted approach, Creatures series games were driven by detailed biological and neurological simulation and their unexpected results.

https://en.wikipedia.org/wiki/Creatures_(video_game_series)

I bought it on [well-known website that sells old, DRM-free games) but it was a bit... too old? So I never quite played it. So I have no clue how well the whole idea worked out.

The closest I've got to that is Disco Elysium.