Podcast Episode 8: In-Game AI

[SevenSpirits]

A lot of things could be precalculated and set up up as priority values. Look at chess opening books as an ultimate sample.

From what I understand, the developers use this trick quite actively. But it has a drawback, since these values may require reconsidering with each balancing patch.

stealth_nsk, you said specifically that you could have the AI beat humans with just better calculation. Now you're contradicting yourself.

But I also doubt that with strong pre-programmed human strategies they AI could beat strong human players. Combat alone is too hard.

 

[stealth_nsk]

stealth_nsk, you said specifically that you could have the AI beat humans with just better calculation. Now you're contradicting yourself.

It could beat in better tactics (both combat and building) calculation and not loose that much with pre-calculated strategic decisions.

But I also doubt that with strong pre-programmed human strategies they AI could beat strong human players. Combat alone is too hard.

Combat is the easiest task for AI. In Panzer General, even with more complex combat, AI often beats human on computers which are less than half as powerful as modern mobile phones.

 

[SevenSpirits]

Great, good luck!

 

[Marshall Thomas]

The lecture explained that the Civ4 AI did NOT have lists of build priorities ("build temple, then barracks"), but the AI thought about which basic items they need (culture, production,...) and built the buildings that provided this, no matter what they were called. That made the AI quite resistant to patches and mods.

Does this mean that if you mod social policies (for example) and change their effects, you won't have to worry about the A.I. adapting to your modifications? If so, that's great news because modding is in vain if the A.I. doesn't recognize and adapt to your rule changes.

 

[Tomice]

Does this mean that if you mod social policies (for example) and change their effects, you won't have to worry about the A.I. adapting to your modifications? If so, that's great news because modding is in vain if the A.I. doesn't recognize and adapt to your rule changes.

I'm not sure about details, but from what I understood from the dev talk, they are trying to consider such problems.

 

[Schuesseled]

Oh My G...oodness "ai increases with difficulty"

But unfortunately they probably haven't seperated the handicap from ai difficulty, so if i ever want to experience good ai, i have to incur a penalty to happiness and science and production or whatever, how lame is that. I'll just keep playing prince and forget i heard about improved ai.

 

[r_rolo1]

^^Given how TheMystic cilindrated the AI in his Prince game ... well, I'll let you take your conclusions

 

[Rebel44]

Based on what Ed said, it sounds like the AI will take longer to take its turns as you go higher up in difficulty.

Very interesting information here (this podcast). My only fear with this new AI design is that the hardest difficulty be too easy to beat. I hope there are still enough handicaps to prevent that happening.

Thats why we have quad core CPUs, 8GB RAM, SSDs etc.

My only complaint regarding system requirements is that 64bit executable wont be available on realease day (I hope that at least it wont take long to add it)

 

[Rebel44]

But unfortunately they probably haven't seperated the handicap from ai difficulty, so if i ever want to experience good ai, i have to incur a penalty to happiness and science and production or whatever, how lame is that. I'll just keep playing prince and forget i heard about improved ai.

Its likely that such bonuses/penalties will be in LUA files which can easily be modded.

 

[Guardian_PL]

But unfortunately they probably haven't seperated the handicap from ai difficulty, so if i ever want to experience good ai, i have to incur a penalty to happiness and science and production or whatever, how lame is that. I'll just keep playing prince and forget i heard about improved ai.

Mwahahaha...
Well, Shuesseled, the only thing I can say is that Azazell keeps playing in his build of Civ5 (the one from which we had this great preview a while ago) and... He keeps losing
Yup, it's been like a month or two so far and he still keeps losing On Prince actually
He might not be a great player, but he's definitely a fan ^^

If that's not a sign of a good, adaptive AI then I don't know what is.

Thank you very much 2kGreg for the podcast transcript, and after reading it my hype about the game has increased even more, had no idea I can still be more hyped, but I am.

O boy, it'll be non-stop orgasm from 24th onwards...

 

[Tylerryan79]

If the AI makes good desicions, they won't need bonuses to win. Great players will always beat the computer, bonuses or not. I don't know squat about programming, so if people think there must be bonuses then I'll agree, we will all know in less than two weeks for sure!!

 

[tom2050]

Just a note of caution, the AI is always made to sound better than it actually is; this is always the case before the release of a game. It likely won't turn out to be the miracle they just made it sound like. Although it sounds like it will be the best so far in the franchise, a definite step forward by any means.

 

[mjs0]

But unfortunately they probably haven't seperated the handicap from ai difficulty, so if i ever want to experience good ai, i have to incur a penalty to happiness and science and production or whatever, how lame is that. I'll just keep playing prince and forget i heard about improved ai.

I'm happy to mod the difficulty levels so I can play against the most intelligent AI with no handicap and see what difference it makes.

Thats why we have quad core CPUs, 8GB RAM, SSDs etc.

My only complaint regarding system requirements is that 64bit executable wont be available on realease day (I hope that at least it wont take long to add it)

Yeah, that is a little disappointing.
It may be that the 64bit exe will arrive at around the same time as the SDK and that this is part of the reason for the delayed release of the SDK. I'm guessing there are some issues to work out especially around how to release the SDK so as mods based on the SDK can be installed for both 32 and 64 bit.

A few off-topic technical notes on 64bit:

Spoiler :

It will be interesting to see how mods that change the SDK will be deployed when the exe could be either 32 or 64 bit, since a 64 bit exe will require the SDK to be compiled as 64bit also.

Delivering a 64bit exe requires that all components of the app be compiled, tested and deployed as 64 bit since, as far as I know, there is no in-process thunking between 64 and 32 bit code as there was between 32 bit and 16 bit; you can 'call' 32-bit dlls from a 64 bit app with a little work but only by using a surrogate process, which carries a heavy performance penalty.
Of course if the interface between the exe and the SDK dll is dirtied by passing pointers around as it was in Civ4 even this would not be possible.

On a different topic:
Whilst I found the podcast very interesting I was disappointed it didn't talk about concurrency. With the AI split into multiple subsystems that communicate by way of requests there should be a lot of opportunity for this to happen in parallel and for the work to be spread across multiple cores.

 

[Ahriman]

So, the AI is deliberately dumbed down on lower difficulty levels?
Ah well.
Hopefully the higher levels will still be a challenge.

 

[Tomice]

I hope they don't only talk about the combat AI. My biggest problem with the AI in BtS is how strangely they improve their land sometimes. Although I have a feeling it improved in later patches.

Maybe it was also my rule change to 3 tile min city distance that made the land I conquered no longer so worthless.

 

[Me,myself,and,I]

Yay! Culture from dead enemies. I'll will build my utopia on the broken bones of those who would dare oppose me.

This also means that the cultural advisor will be in agreement with the military advisor, "Give me more soldiers Noble Leader! So that they may sheath their swords in the beating hearts of our enemies!" "I agree sire. God what am I saying?"

 

[wapamingo]

I hope that when choosing difficulty levels on game start-up, the tooltip properly explains exactly the "smartness" of AI (pick a scale out of 10) and bonuses at each level (+25% production at X, +50% production at Y, whatever...)

 

[RedFury_au]

As someone who used to be a game AI programmer and has an appreciation for how amazingly difficult it is, if the AI can truly keep up with a top-notch human player without cheating then I'd be starting to get nervous about the straight-forwardness of the strategic choices available in the game.

Sounds harsh, but geez if an AI is bonus-free against great human players in a truly complex, nuanced and highly strategic game which has many viable, open options at any one time, then they've got some of the best technical people on the planet IMHO.

 

[Semmel]

Than Civ would be almost as deap as chess.. to be honest, its too good to be true and history has shown us, things that are "too good to be true" are likely the effect of clever marketing rather than clever programming. Lets see how this goes, but I dont beleave it unless I see it. And to be fair, they never said the AI doesnt cheat. They just didnt say it does.

 

[Chiyochan]

My face when fraxis is implying civ4 AI DOESNT cheat.