Archived

This topic is now archived and is closed to further replies.

Diodor

Predictable AI vs. Strong AI

Recommended Posts

Diodor    517
Which of the two allows for better gameplay and under which circumstances? By predictable AI I understand a computer player that has large-scale reactions to the players moves, but these reactions are easy to predict, giving the player a significant advantage. The AI doesn''t need to shoot itself in the head (some would argue this is already strong AI ), but it is obvious it doesn''t perform as good as it could. A Strong AI is carefully tuned for just one purpose : to win. It''s complicated algorithms are in no way predictable, and it is also hard to put the computer player into very disadvantageous situation. I believe the predictable AI is better because it adds a new layer of gameplay: planning a sequence of actions and computer reactions. If it''s not as challenging as the strong AI, I see no reason why the challenge against a predictable AI wouldn''t come from some material advantage the computer player enjoys.

Share this post


Link to post
Share on other sites
Inmate2993    222
This type of thing highly depends on how its implemented. If this were an RPG and the predictable AI were to always use some Effect-Canceling magic on himself if he were poisoned or something, then the player can just make sure to poison the enemy before his turn comes up. If it were a FPS and the enemy made sure to get all grenades and throw them back, that gives the player a window to attack the AI and a clear tactic against those type of enemies.

On the other hand, a strong AI, designed to win, would do just that, always win (conditional to the fact that such an AI can be programmed). And you don''t want that, the player would never make it out of the boat at normandy.

For a well balanced game, you''d want a strong AI with a glaring flaw, and the enemies to be placed in such an order that the player can defeat them and not find a impossibly strong one blocking the path.

Share this post


Link to post
Share on other sites
Sandman    2210
I think Strong AI is nearly always preferable for computer opponents, it's just a lot harder to program.

Example: Starcraft has a fairly predictable AI. It makes up for this by taking advantage of the fact that the computer can micromanage all it's units perfectly, so while it can still be challenging, it gets old pretty fast.

It also means that many tactics which are valid against humans are obsolete against the computer, and vice versa - so rather than playing vs. the computer being a training exercise, it's almost like playing a completely different game.

I'd love to see an RTS with an AI so good it can challenge a human player without having to compensate (or 'cheat') with its godlike micromanagement. Is it possible? I don't know, AI isn't one of my strongest subjects.

I'd also like to see games with more configurable AIs. Anyone remember the original Settlers game? Each computer player had sliders so you could alter their early game advantage, skill level, aggressiveness etc.


[edited by - Sandman on May 29, 2003 2:10:45 PM]

Share this post


Link to post
Share on other sites
Ketchaval    186
The following quote from a very interesting game-design oriented review of Half-Life by Witchboy

http://www.planetdeusex.com/witchboy/halflifereview.shtml


quote:
original article by Witchboy



Some people-developers and gamers alike-are often tempted to think "predictability equals boredom" in games. Nothing could be further from the truth. Think about Tetris-the player, if given time, can always figure out how a particular piece will fit into the blocks below; there are no amorphous shapes or wild, random block behavior. Similarly, one of Half-life''s most brilliant features is the consistency of the behavior exhibited by (almost) all the game''s elements. This allows the player to a) easily learn how to deal with these elements and b) to work out cool combinations of interaction. The things that prevent this predictability from being boring are numerous-the combined interactions of the elements, the fun of dealing with them and learning to master them, the slight variations created by the player''s input and other ''randomizing'' simulation elements. Plus, there are lots of these simple, predictable elements, not just a few. The key is that the game as a whole is not predictable-just the individual pieces.

.....


Facing off against game units that exhibit some interesting, consistent behaviors is much more fun that going toe-to-toe with some giant boss monster. Instead of just shooting at the thing for five minutes, the player suddenly has more freedom in interacting and his problem solving abilities are engaged. Way to go, Half-life. Let''s hope more games catch on to those concepts.




...

As you can see predictability has an important place in gaming.


Personally, I think that it would be very interesting to see a combination of predictabile behaviour and Strong AI.

So that you have (some) enemy creatures that have their own initiative, which goes beyond a simple search pattern... instead, there are several search / stimuli response patterns.
So one will duck behind cover and peek round, whereas another might be braver and start searching.

On the one hand, if you can predict how the enemy characters will behave this allows you to make plans. But if on the other hand they are more realistic and individual, then the suspense and level of unexpected behaviour should dramatically increase. Personally, I would like to see more games that can surprise you.. and that seem to have creatures that use intelligence to deal with their surroundings.

Share this post


Link to post
Share on other sites
OklyDokly    122
I think that one of the advantages that strong AI has over predictable AI is replayability!!! It''s more fun second time round if you don''t know what the opponent is going to do next.

Saying that though, I think that developers can get a lot more first time playability out of predictable AI. Just take the older console games for example. I remember one particular game on the Mega Drive, Rocket Knight Adventures, which I had great fun playing with some friends when I was younger. The whole fun was playing through the predictable AI again and again, until we could finally beating in it, then the ability to tell ourselves we rock . Took a lot of routine button mashing in a way, kinda like learning a piano piece.

Share this post


Link to post
Share on other sites
Diodor    517
quote:

Original post by Inmate2993

This type of thing highly depends on how its implemented. If this were an RPG and the predictable AI were to always use some Effect-Canceling magic on himself if he were poisoned or something, then the player can just make sure to poison the enemy before his turn comes up. If it were a FPS and the enemy made sure to get all grenades and throw them back, that gives the player a window to attack the AI and a clear tactic against those type of enemies.



These are valid examples where predictability is bad because it doesn't enhance but it simplifies gameplay.

quote:

On the other hand, a strong AI, designed to win, would do just that, always win (conditional to the fact that such an AI can be programmed). And you don't want that, the player would never make it out of the boat at normandy.

For a well balanced game, you'd want a strong AI with a glaring flaw, and the enemies to be placed in such an order that the player can defeat them and not find a impossibly strong one blocking the path.



There are more ways to balance a game than AI. I think fighting with throngs of units against a small but very elusive AI player can be good fun (as can be fighting with very few units against a dumb but large enemy).


[edited by - Diodor on May 29, 2003 4:02:50 PM]

Share this post


Link to post
Share on other sites
Diodor    517
quote:

Original post by Sandman

I think Strong AI is nearly always preferable for computer opponents, it''s just a lot harder to program.



Yeah.. Well, a good excuse for laziness is always handy

quote:

Example: Starcraft has a fairly predictable AI. It makes up for this by taking advantage of the fact that the computer can micromanage all it''s units perfectly, so while it can still be challenging, it gets old pretty fast.



But is the AI reactive? In other words, can you lure it to attack where you want it to, or can you control it''s choices in an useful way?

quote:

It also means that many tactics which are valid against humans are obsolete against the computer, and vice versa - so rather than playing vs. the computer being a training exercise, it''s almost like playing a completely different game.



Yes, the predictable gameplay pretty much goes out the window in multiplayer games. It doesn''t need to: computer players can be added in multiplayer games. Even if they don''t challenge the human players, they can be a source of gameplay as human players compete to control the choices of the AI ones.

quote:

I''d love to see an RTS with an AI so good it can challenge a human player without having to compensate (or ''cheat'') with its godlike micromanagement. Is it possible? I don''t know, AI isn''t one of my strongest subjects.



This _may_ be more of a matter of game design than of AI programming...

Share this post


Link to post
Share on other sites
Diodor    517
Ketchaval, that was a good read. Reminded me of Thief. IMO, Thief is the classic example where predictable AI leads to amazing gameplay that would be impossible with strong AI.

quote:

Personally, I think that it would be very interesting to see a combination of predictabile behaviour and Strong AI.



Yes, but the stronger and more complex the AI the harder it is to keep it predictable. In Thief for example, the AI is carefully and deliberately kept predictable by the vocal messages that tell the player the state of the AI characters.

I agree that strength and predictability do not necessarily rule each other out.

quote:

On the one hand, if you can predict how the enemy characters will behave this allows you to make plans. But if on the other hand they are more realistic and individual, then the suspense and level of unexpected behaviour should dramatically increase. Personally, I would like to see more games that can surprise you.. and that seem to have creatures that use intelligence to deal with their surroundings.



Incidentally, the game that surprised me most (to the point of screaming actually ) was Thief. If you teach the player to expect some game behaviour, it''s easy to surprise him by breaking in some way those expectations.

Share this post


Link to post
Share on other sites
CheeseMonger    198
Someone above mentioned StarCraft...

...if predictable AI that can micromanage like a god is a challenge, would a strong AI that can only move one unit at a time, like the player, be the same amount of challenge?

- CheeseMonger

Share this post


Link to post
Share on other sites
eglasius    122
yes it can be the same amount of challenge, but we are limited ... (processing power and implementing them in a really good way).

about replayability ...

well, it depends in how you draw the lines between predictability and strong AI ... "predictable AI" can act depending on many factors (a concept called faction is one of them, which on my understanding means your reputation with a certain species/race, lets say World Of Warcraft, your reputation with the trolls ...thus, before the event you wont know what will happen, but you know that if someone interacts with that npc and its on the same reputation as you it would get the same results), thus while you get more and more factors in with "simple" AI you can get different behaviors (you would get similar behaviors with your same char, but if you start all over you would get different behaviors, of course if you take a different path on the game ...).

Well, of course that means you take different actions to get a different experience (even small ones), which might not be the case for certain types of players, here is where real Strong AI comes in for replayability ...

you might want to put Strong AI in your game for this replayability aspect, my advice is go ahead, just dont put it in unnceserarily (since it is more performance costly than "predictable" AI ...)

Share this post


Link to post
Share on other sites
irbrian    130
Generally speaking, I''m of the opinion that Predictable AI is a necessity only of programming/processing capability, NOT of solid gameplay. More often than not, a predictable AI simply makes a game less challenging (unless the AI cheats). To me this is not the definition of quality gameplay.

I''m looking forward to AI that performs (as near as possible) like a human player, while experiencing similar limitations to those that humans experience. It may still make games more challenging, but frankly I feel much more satisfication when I defeat an intelligent, strategizing opponent than a dumb, predictable one.

There is an exception though: In any game where the player is facing off alone against a multitude of allied enemies (such as Thief, or most other single player FPS games) the enemies have a distinctly overwhelming advantage if they are all nearly as capable as the player. I couldn''t imagine playing Return to Castle Wolfenstein if all the nazis were as good at hunting me as I was at hunting them. Predictability in these games is vital, because lets face it: Most of us just aren''t smart enough to outsmart an army single-handedly.

Fortunately there''s a middle ground. RtCW is a good example in fact. Each enemy has a number of pre-defined possible actions they might take depending on the situation -- if they''re being shot at, they take cover; if they see that you are unarmed, or that they have greater firepower, they advance. They duck/dodge/etc. They also work in small teams, taking turns firing and then taking cover. They might just sound an alarm and get their friends to attack you.

Enemies are still predictable, because they have a limited amount of actions they can take, and they don''t actually strategize -- they just take the action that is determined to be the most appropriate based on the given situation. But they feel a lot more threatening because they seem more intelligent, even though they really aren''t.

****************************************

Brian Lacy
ForeverDream Studios

Comments? Questions? Curious?
brian@foreverdreamstudios.com

"I create. Therefore I am."

Share this post


Link to post
Share on other sites