Civ III AI - This explains everything (at least to me)

[BillChin]

1) For the right script to be used, the AI has to be able to convert the player’s game position into something the AI can use, possibly like a set of (weighted) values.
- Ideally yes, but a decent AI may be feasible without this. Basic information such as the power graph, the number of cities in each empire, the population, the industrial output, may give a crude approximation. Add a randomizing factor and the AI may be okay without a lot of work on evaluating details. The easy way out is to make the person writing the script responsible for making sure that it is appropiate to the game situation.

2) Second, the current situation. This relates to the first point. In order to choose a script, you have to understand the position you’re in.
- Again, the time line, the number of cities, and other factors are useful guideposts. This may be a crude approximation, but may be sufficient. For example, it is inappropiate to use Swordsmen Conquest past 200 B. C., or after 10 cities, or after Republic or Monarchy is discovered.

3) Third, the changing situation. Over the course of the game, some things become less important, while others become more important. Once the AI player has developed a defensible core of cities, survival becomes less imperative, and the AI can turn its attention to expansion
- This may be a big stumbling block. In the example I outline the war is launched, but then what? Is it better to bypass outlying cities and head for the capital? Or better to attack straight off. What to do if half the attacking force is lost taking the first city? This may be a tough nut. As of now, I do not see an easy way around the boulder and it could become a nest of micromanaging code for little benefit.

4) Fourth, the value of each script. In order to work well, it seems like you’d want to have multiple scripts available all the time, and then choose the best one.
- The value may be best determined by having the AI play other AIs. With all graphics and autosave turned off, an AI only game might only take a few minutes on a fast computer. Multiple computers can be used (hardware is cheap compared to programmer time). If the program is really clever, it might try and build some kind of database so it knows what sub-scripts work well in certain situations. This is a lot to ask. A simple Darwinist model is easier to envision.

I see the real power coming from fans writing scripts and competing against each other. Bad scripts will get tossed in an hour. Good ones studied and built upon. The AI is not really doing the evaluating, the fans are. The process is dynamic as better tactics come with each generation of fan scripts. I see this process leading to a superior AI. Remember my premise, that the problem (a better AI) is mainly one of time and resources, not technical or programming issues. By harnessing the virtually unlimited time and talent of the fan base, a better AI will come.

I define "good" as an AI that can defeat 80% of players on a level playing field. Even if everything I wish for is put in, the top human players will be able to beat the best scripts most of the time. However, I believe the vast middle class of gamers will be able to enjoy a challenging game without resorting to the AI bonus system. I see this as a major step forward.

I estimate the current AI can defeat 20% of players on a level playing field. Considering the eight month, single programmer time line, Soren Johnson deserves a big thumbs up for the Civ III AI. I shudder to think about the time line and resources required for a good script engine project.

There are simpler approaches. One good one suggested here, is a series of sliders for a lot of different AI controls. This would involve minimal overhead, testing, and support. If done with some creativity, this has the potential to add a lot of variety to the AIs. Add in a small chance to change some of the settings every dozen turns or so and the AI becomes less predictable and more interesting to play against.

[Mark_Everson]

Originally posted by BillChin
What to do if half the attacking force is lost taking the first city? This may be a tough nut. As of now, I do not see an easy way around the boulder and it could become a nest of micromanaging code for little benefit.

Hey Bill:

I expect there must be scripts that describe under what circumstances one should abandon an attack or try to extract oneself from an offensive. These could be phrased in terms of overall power of the combattants. Even better if available would be forces available at a "front" level. When things look bad as defined in the script the script should describe escape avenues from digging in where you are and aborting the attack, strategic withdrawl, trying to make peace while keeping limited gains, removing allies that contribute to the forces it is fighting, attempting to add new allies to change the balance of power.

But it does get pretty complicated quite quickly. I don't think there is any way around this. Scripts are basically a fairly rigid solution, and if you go that way, you need to cover a lot of bases or the AI will have big holes in it that can be exploited by the players. It'll be interesting to see how the Galactic Civ AI does when it comes out. The earlier version of the game apparently had pretty good scripted AI taking into account lots of fan input to add new strategies and plug exploits.

[Spaced Cowboy]

Wow, excellent thread. Please continue, I have much learning to do....I might be working on a game AI myself so any insight would be useful.

R:PM

[Nym]

Originally posted by Trip
Before another whine-fest, ala "civ 3 sucks" starts up again, I point you all to this, originally posted in the very top thread...

#151 HOW AND WHY DO BAD GAMES GET MADE AND PUBLISHED
http://apolyton.net/misc/column/151_bad.shtml
by Ex-Activisioner David "Pyaray" Ray

Very good idea to pinpoint this article.

Whatever, IMO, Soren really did a good work in a so short time.

[MBD]

Originally posted by BillChin
I see the real power coming from fans writing scripts and competing against each other. Bad scripts will get tossed in an hour. Good ones studied and built upon. The AI is not really doing the evaluating, the fans are. The process is dynamic as better tactics come with each generation of fan scripts. I see this process leading to a superior AI. Remember my premise, that the problem (a better AI) is mainly one of time and resources, not technical or programming issues. By harnessing the virtually unlimited time and talent of the fan base, a better AI will come.

I guess I don't understand this part. When you talk about AI scripts, is it one big script for the whole game, or some kind of super-script that pulls in sub-scripts as the situation requires? It seems like testing one game-sized script against another game-sized script would be almost impossible.

Also when you say "time and resources" what resources are you talking about?

[BillChin]

Originally posted by MBD

I guess I don't understand this part. When you talk about AI scripts, is it one big script for the whole game, or some kind of super-script that pulls in sub-scripts as the situation requires? It seems like testing one game-sized script against another game-sized script would be almost impossible.

Also when you say "time and resources" what resources are you talking about?

Resources in publisher terms means money, which translates into programmers and/or computer hardware and back office support. Allowing fans to work on the AI harnesses all their computers and their time.

The way I see it, each computer civ will have the ability to have a separate game-size script. Just as a player may choose different civs to play against, there would be an option to select different scripts for each of them. Also a random function to choose from the pool of all available scripts. Perhaps these game-size scripts can pull ready made modules off the shelf so each big script is a big picture overview. Fans would also have the option of optimizing the smaller modules.

All of this is "blue sky" talk, meaning it may not be feasible at all if push comes to shove and work has to commence.

[Grumbold]

Scripts like most programs are normally modular. So if the game company has written awesome city management code and brilliant routefinding but somehow managed to let ships prefer to coastal bombard empty squares than blockade ports, a user could (after a lot of examination of the code, replace part of the ship AI while hopefully leaving everything else unchanged.

If you look at CtP2 download section you can see this in action. There are many mods that improve one or two features or add one or two units. There are a few huge mods that pull together the best changes made by a whole team of players.

[monkeyman]

Hi,

I have one more topic to broach, and that's the usefulness of editable AI when one is making a major mod. Questions you always have to ask when modding the game for single player use:
Will the changes I make be used effectively by the AI?
Can I adjust the AI to effectively use these changes?

For scenerios of course this is even more critical.

What would the best (ease of use vs. adaptibility) strategy to implement these concepts be?

--mm