I have been pondering the role of AI in MMORPG games. From simple reactive-based enemies to complex dungeon generators, Artificial intellingence plays a lead role in all mmorpgs. However it is all very simple and predictable and could use a good upgrade imo. The most powerful enemies should learn over time, forcing people to adjust their tactics instead of reading about their weaknesses on thottbot. In some games, agent embodied behaviour could be embedded into npcs to make them more beliveble. Emergent behaviour could be seeded with planning algorithms and more advanced model based agents. I´d love to hear ideas, opinions and perhaps any plans you might have to increase AI in MMORPGs, where you would like to see more advanced behaviour and where not.

MMOs face the basic problem that NPCs, once they encounter players, don't typically live very long. This leads to several problems when you want to have your NPCs learning intelligent behaviours. Furthermore, the next player they meet probably wont be that same as the last player they met and hence the strategy they try to employ will probably be inappropriate.

Personally, I think that MMOs do just find with having 90-95% of mobs being 'chaff' and the remainder being involved in encounters that last longer and require tactics. Take WoWarcraft as a good example. Most if not all mobs in the normal zones could be chaff. There to die quickly for the amusement and advancement of players. Mobs in instances could be made not tougher, but smarter; learning how to use the instance to their advantage and learning how to better adapt to the strategies that players come up with.

Most of this learning though should be conducted during offline analysis after a battle and a new strategy added to a 'book' of strategies that could be used depending on either the composition of the player forces or the rough strategy they employ.

Personally I think the fault doesn't lie with the AI developers for MMOs nor with the encounter designers, but rather that the designers simply don't have the tools to create 'intelligent' encounters and must rely on their experience, which necessarily limits the sorts of encounters that the player will face. Give the designers better tools and they'll do better work (usually).

Well, MMORPGs pose a very interesting challenge in itself. It is pretty much one consistent world all players play in. Having npcs that learn from player encounter over time poses many challenges in game balance in the long run.

Let's just assume that all low level npcs that are killed spawn from some sort of boot camp, which teaches them strategies. So, everytime you kill something, this "boot camp" learns something new to teach to the next generation. So, technically, as the game "ages" the NPCs will become more and more experienced. So, here comes the game balance issue. The purpose of low level NPCs is to help new players level up and get over the initial learning curve of the game, but now you have a generation of low level NPCs out there with some rather good tactics and harder to kill than they should be. This will completely throw off some of the game balance in the long run, as it becomes harder for people joining later to play the game or even learn it.

Even if we limit this learning to higher level or special event NPCs, this still throws things off somewhat as people who "came first" have the distinct advantage of going up against something "relatively easier" than say the 10,000 person to meet this monster.

So, in improving AI in an MMORPG, you may in fact be cutting out your target audience to just the people who started playing when the game was released or those who "have no life" and sit and play for long periods.

So, personally, I think more advanced AI hasn't been used in MMORPGs is just because they may cause game balance in the long run and may in some case discourage new people from joining.

The problem in this case should rather be, how do you create a predictable AI that is still hard to beat. You know all its moves, but talking about how to beat it is easier than the execution.

Personally, I feel the AI in MMORPGs should be there to make things hard enough to do on your own, but easy enough if you have a group of people who can work together in the right way, utilizing specific tactics. From my experience with FFXI, I've learned that everything sounds good and easy on paper until you really have to execute, that's when the difference between the player and noob is drawn.

The other huge constraint on MM ai is computation. There are likely a huge number of entities actively interacting with players at any given time. By increasing the complexity of any significant portion or entities you add a significant burden to the server's workload.

It seems to me its by necessity that the vast majority of entities can't become more complicated that simply reaction based and rail-driven.

Quote: Original post by WeirdoFu
Well, MMORPGs pose a very interesting challenge in itself. It is pretty much one consistent world all players play in. Having npcs that learn from player encounter over time poses many challenges in game balance in the long run.

Let's just assume that all low level npcs that are killed spawn from some sort of boot camp, which teaches them strategies. So, everytime you kill something, this "boot camp" learns something new to teach to the next generation. So, technically, as the game "ages" the NPCs will become more and more experienced. So, here comes the game balance issue. The purpose of low level NPCs is to help new players level up and get over the initial learning curve of the game, but now you have a generation of low level NPCs out there with some rather good tactics and harder to kill than they should be. This will completely throw off some of the game balance in the long run, as it becomes harder for people joining later to play the game or even learn it.

Even if we limit this learning to higher level or special event NPCs, this still throws things off somewhat as people who "came first" have the distinct advantage of going up against something "relatively easier" than say the 10,000 person to meet this monster.

So, in improving AI in an MMORPG, you may in fact be cutting out your target audience to just the people who started playing when the game was released or those who "have no life" and sit and play for long periods.

So, personally, I think more advanced AI hasn't been used in MMORPGs is just because they may cause game balance in the long run and may in some case discourage new people from joining.

The problem in this case should rather be, how do you create a predictable AI that is still hard to beat. You know all its moves, but talking about how to beat it is easier than the execution.

Personally, I feel the AI in MMORPGs should be there to make things hard enough to do on your own, but easy enough if you have a group of people who can work together in the right way, utilizing specific tactics. From my experience with FFXI, I've learned that everything sounds good and easy on paper until you really have to execute, that's when the difference between the player and noob is drawn.

Possibly changing the way that experience is generated would shift that problem
(noobs facing oversmart AI).

I remember playing UO and NWN and being very happy to just get out of a very nasty situation (ie- instant spawns around the players is such a dumb thing)
by skillful tactics. Too bad I didnt get any experience points for doing it.

Rewarding experience for a wider range of actions (not just Hack/Slash/Loot)
counld help break out of the lame patterns that MMORPGs usually use.

Making a shallower character development path and much greater emphasis on doing the right tactic and using discovered game knowledge (thinking your way out of a situation) might also be a big improvement. And with an extensive quest generator to prevent repetative/repeatable situations, the problem of a noobs pre-learning all the shortcuts would be greatly lessened.

AIs could also be made to scale the difficulty of the assigned quest tasks or at least give outclassed noobs adaquate opportunities to runaway/make a partial success.

Quote: Original post by WeirdoFu
Let's just assume that all low level npcs that are killed spawn from some sort of boot camp, which teaches them strategies. So, everytime you kill something, this "boot camp" learns something new to teach to the next generation. So, technically, as the game "ages" the NPCs will become more and more experienced. So, here comes the game balance issue.

This is something I've considered. Do you think it's conceivable that training the agents based on their observations/experiences may be counterproductive? Initially many MMO*s suffer from a particularly steep learning curve. Having agents that learn from what are essentially "dumb" players that are muddling through their first experiences of a game may result in less than optimal training.

Using one of my early MMO experiences as an example, the space-sim Jumpgate, the learning curve was incredibly steep and people often died to the very basic AI (not to mention splashed themselves against asteroids and stations thanks to the pseudo-Newtonian physics engine). Would training the agents based on this sort of behaviour result in them learning bad strategies, especially as the player's own skill improves quickly?

Andy

Quote: Original post by Atavist
The other huge constraint on MM ai is computation. There are likely a huge number of entities actively interacting with players at any given time. By increasing the complexity of any significant portion or entities you add a significant burden to the server's workload.

It seems to me its by necessity that the vast majority of entities can't become more complicated that simply reaction based and rail-driven.

You said it before I could. AI is expensive and there are THOUSANDS of mobs running around that implement some sort of AI. It becomes a tradeoff between gameplay and cost.

Quote: Original post by WeirdoFu
So, everytime you kill something, this "boot camp" learns something new to teach to the next generation. So, technically, as the game "ages" the NPCs will become more and more experienced. So, here comes the game balance issue. The purpose of low level NPCs is to help new players level up and get over the initial learning curve of the game, but now you have a generation of low level NPCs out there with some rather good tactics and harder to kill than they should be. This will completely throw off some of the game balance in the long run, as it becomes harder for people joining later to play the game or even learn it.

If the AI is properly trained before the game is published, more experiance does not neccessarily mean that they actually get better. It just means that the same tactics will not work on them every time. As players change tactics, the NPCs will be forced to adapt as well but they would never be given more power and should never be able to find an optimal strategy.

Surely improved AI would call for vastly more computation power but in turn more clever enemies mean longer encounter and that we need less of them. Of course this may not compensate completely but should make it less of a sacrifice at least.

In addition, AI does not have to be restricted to enemies. Advanced dialogue systems and gestures could make neutral NPCs and players alike become more alive and beliveable; The interface could learn how you like to do things and make it easier for you to use the features you commonly use and cut out those you don´t; Running between places (corpseruns anyone?) could be automated with ligthweight but large-scale pathfinding algorithms etc etc.

That's why I'm actually fond of the idea of a dedicated bootcamp server for AI in MMORPGs and anything else. A server dedicated to evolving NPC behavior. When an NPC dies, they go back to bootcamp and gets evaluated as to whether they get retrained, sent back out again as is, or just deleted. This could work for MMORPGs and FPS bots alike, which could improve single player game replayability too if implemented correctly. The key is to have the proper performance metrics such that the bootcamp can actually learn "useful" things.

The hardest thing about designing MMORPGs, for me, is content. You are creating a virtual for thousands of players. This has to be a coherent world that obeys fixed physical rules, but yet be rich in content. Random content generation is nice and dandy until you hit coherency barriers. You don't want to have to go to an NPC and have them ask you to retrieve their dead son's corpse, and next day come back and have them ask you to save the same son from some dungeon. Just being able to have things make sense is very hard. You need to be able to believe that an NPC actually "lives" in that world, and that is the hard part.

Technically, everyone can make an MMORPG, just look at the situation in asia where there's like a constant 10 - 20 MMORPGs on the market at the same time. The problem is the content. Do you have a deep enough world that goes beyond the gloss of pretty graphics to keep players interested. I think just the focus itself on deep rich content over-rules the need for any form of complex AI.

In the end, I feel that to make a successful MMORPG, its not just pretty graphics or good AI even. Its the richness of this virtual world you created and how much content you actually have to lure players back again time after time. Is the experience immersive? Do I really feel that I am in a different world? Do things make sense? Is the story attractive? Finally, is it fun?

To ease the learning curve problem you could perhaps allow npcs access to some of the opponent data and change their attack tactics based on this. For example, in most rpgs you get the 'fodder' npcs that take a few blows to kill when you first start off but when you become harder they simply get annoying and pose little if any threat. If these npcs realsied you were a tougher opponent perhaps they could adopt group tactics joining into gangs before attacking so that the player is constantly challenged. Noobs can still improve their stats and get into the game and experiencd users don't grow tired of the creatures.