Aggressive AI

[Solver]

If you haven't tried playing with the Aggressive AI option on, try it in BtS. It will improve the overall AI performance as the As become more competitive. It's an option for hardcore players. In BtS, Aggressive AI does not mean elimination of leader personalities. It doesn't mean that Gandhi will go berserk and attack everyone. Here's a RB post from Blake on the subject.

Originally posted by Blake
I'm 100% responsible for the AI in BTS.

Making the normal AI wussier was MY decision, granted it was a decision made partially on the basis of impassioned pleas (pfft, whines) for less unit spam, I am by nature every bit as cruel as Sirian when it comes to making life difficult for players, and yet that cruel tendancy ends up getting moderated, probably by compassion.

Basically there was:
Things I had time to do
and
Things I didn't have time to do

I can't think of anything I implemented which was not included.

Have you seen the list of changes in BTS? The number of new systems? To say as little as possible, there was not nearly enough time to perfect things, most time was spent making sure as little as possible was broken.

If I had spent the time to make an impassioned argument for replacing Aggressive AI with Peaceful AI then I'm fairly certain it would have happened - in spite of the obvious backlash about "Pointlessly changing things around" (trust me, however pointful something is, there will always be some who find it pointless...).
But other things got my attention (requiring impassioned arguments ), when there are things which are broken, those things take precedent over things which aren't perfect. Perfection is unattainable anyway, while not broken is attainable.

This is not a criticism of the BTS development, it can be called corporate reality if you want. Was BTS too ambitious? Maybe... probably... but I think it's still better than not being ambitious enough.


To further explain AI military behavior.

A naturally militaristic AI like Alexander or Monty will still make a respectable military effort under normal settings, in AI vs AI wars, it's all relative anyway. Some AI's have to be bad at defense, so others can invade them. In BTS the AI are far less "samey" in their strategy - in short they can pursue goals, but obviously in min-maxing their metagame they sometimes make themselves extra vulnerable to be invaded, it's the price of not being samey/predictable.

Aggressive AI no longer causes the AI to have a relationship penalty with humans. Basically it can be said that the AI expects things to get aggressive. The pacifist AI's aren't actually that much more likely to declare war, they just keep larger armies on hand as to not be easy victims. The naturally militaristic AI's go crazy. In any case if you neglect your army, any AI will notice and with it's larger power will be more likely to declare war and come for you. It is more likely you'll get declared upon, especially if you don't change your playstyle...


The default AI is a bit of a sandbox, you can employ the strategy you want and the AI may interfere with your plans... but on Aggressive AI, the AI can DICTATE your strategy! If Alexander is going to invade you, then you damn well prepare an army or you're going to taken out of the game! Even with the best prepeardedness if you fail to avoid a dogpile you're probably a goner.

On the normal setting, you just play, it's casual.
On aggressive AI, you adapt, it's hardcore.

Note that the vast majority of people who buy the game are not hardcore. Even those that are (proclaim to be) often prefer more of a sandbox style, one of the most common complaints was along the lines of "I don't want the AI forcing me to adopt a play style", in other words the player has to be choose a strategy, and the AI must accommodate them to a degree by not being too aggressive. While Aggressive AI, will be as aggressive as it darn well pleases.

Note that Aggressive AI, due to spending more on units, techs significantly slower than the default AI, if you can somehow stay out of the crosshairs it's actually easier to win peacefully - the default AI can be a speed demon when it comes to research.

What do I mean by difficulty?

Take this as an example: I played a game on emperor level and got a good start, I wiped out my neighbor, then another neighbor. But during that time an AI "tech whore partnership" of Elizabeth and Roosevelt had teched to the end of the tech tree while I was really nowhere near it, the warmongering, despite being successful, had slowed me down. That's part of the new balance of BTS - the AI's can under good circumstances tech very rapidly - in Warlords the AI - even at emperor - was easily capable of not getting to the end of the tech tree before 2050, meaning the player could take all damn game long consolidating a large conquest into an economic powerhouse, in BTS players don't have as much slack, so even if conquering your neighbors isn't harder it can be harder to actually win the game. That's something you get with default AI - you dick around invading people while some AI's refuse to fight and tech off into space. It doesn't happen predictably and I'll put it like this:
If you play at a difficulty which is exactly at your skill level, with 10 players:
10% of the games you should have an easy time, because you got a "top 10%" start point.
10% of the games you should have a very uphill struggle, because you got a "bottom 10%" start point.

Some easy games are to be expected.
(Note: Most players play far below their "equal skill level", in that they expect to win 100% of games, rather than 1/N games where N is the number of players used, this paradoxically is true of multiplayer too - the players just feel like they suck when they only win 1/N games)

Blake, feel like having a conversation about the AI and design goals here? It'd be great if you elaborated further about how AI personality affects AI behaviour on the Aggressive AI setting, you obviously know best.

[Solver]

Aggressive AI in BtS:

Less likely to build culture-focusing buildings.
Willing to pay more for unit supply
More likely to train invader units when massing an army or for counterattack when defending
Decreases the likelihood of going for Wonders by 1/3
When picking an option on how to deal with random events, values relations-boosting choices less (50% of normal).
Considers the Culture Victory less inviting to attempt, in other words, needs more positive culture factors to consider going for it.
Slightly more likely to go for nuclear stockpiling.
Likes the Crush strategy more.
Will mass units when there are juicy targets in the area with more vigor.
Increased probability of declaring war.
More cocky. Evaluates its military power more optimistically than the regular AI.
Settlers may attempt to found cities without escort for more aggressive expansion.
May poach your Settlers or Workers!

[ayronis]

Although I am sure others will follow, let me be the first to compliment you Blake - this was a brilliant (re-)design decision. Both options have clear purposes and uses and, to be honest, I am going to have a very difficult time deciding which setting is more fun.

[Wiglaf]

Aggressive AI should be the default and the normal should be an extra feature. It's just too passive, nothing happens in the standard game.

It's unfortunate to see blake admit BTS' AI doesn't fully grasp the new features in BTS. Corporation and espionage AI does need tweaks. Hopefully he can fix those.

[Solver]

Aggressive AI should be the default and the normal should be an extra feature.

That's your opinion... Blake's too, in fact, if I understand him correctly. The problem is with casual players who wouldn't find it fun. After all, the vast majority of buyers are indeed casual players, they need an AI that is less ruthless and doesn't quite force you to adapt.

The good part about being an experienced Civ player like you or I is that you don't have to care much about what options are default, as you can just set up whatever options you prefer.

[Solver]

An interesting function of the BtS AI is last-ditch defending, or panic defending. If the AI is getting overwhelmed at a certain area, it will do whatever it can to give you trouble conquering it. This can be particularly noticed when you move up to an AI city but don't attack it - the AI will rush extra defenders.

Here's how AI panicking works. If engaged in a land war, it considers the defenses of its city and enemy troops in vicinity (within 2 plots). If the ratio is better than 1:1 in the attacker's favour, the AI will rush its current build project, if it's a combat unit. If it's not a combat unit, the AI will possibly switch production to one immediately, preferring city counter units (that can counter-hit the attacking stack) and city defender units - it will only pick a "regular" attacking unit if it can't pick counter or defense units. The AI will also consider whipping these extra defenders and will always whip if the attacker has a 1.4:1 advantage or better.

[ben04]

I think the Aggressive AI setting should stay.

Casual players will not quickly grasp all the possible settings and it's implications so will most of the time start a default game, meaning don't check anything so they will get the right setting. People that play more often will soon go through the option list and find that switch and activate so they are also happy.

Perhaps a "did you know?" message could point to the option. Moving it to the top in the option list could also help.

[Wiglaf]

Originally posted by Solver
An interesting function of the BtS AI is last-ditch defending, or panic defending. If the AI is getting overwhelmed at a certain area, it will do whatever it can to give you trouble conquering it. This can be particularly noticed when you move up to an AI city but don't attack it - the AI will rush extra defenders.

Here's how AI panicking works. If engaged in a land war, it considers the defenses of its city and enemy troops in vicinity (within 2 plots). If the ratio is better than 1:1 in the attacker's favour, the AI will rush its current build project, if it's a combat unit. If it's not a combat unit, the AI will possibly switch production to one immediately, preferring city counter units (that can counter-hit the attacking stack) and city defender units - it will only pick a "regular" attacking unit if it can't pick counter or defense units. The AI will also consider whipping these extra defenders and will always whip if the attacker has a 1.4:1 advantage or better.

I don't know if it was this complicated, but I'm sure the AI would rush to defend threatened cities in Warlords. In fact this could be exploited -- put a stack outside city A, then once all their units go there to defend, hit city X.

[Solver]

The Warlords AI defense rushing code was worse. It didn't have an elaborate panic routine. It wouldn't whip if it was already close to completing the item, for example. The WL AI would move defenders in from other cities, but the real changes in BtS are about rushing (as in whipping) new defenders at the threatened city.

[vilemerchant]

Anyone noticed the brilliant AI invasion strategy of sending a heap of units to one particular plot of your land, who then just fortify there and do absolutely nothing, until the war ends?

[Fidel]

i have already used warlords aggressive ai setting and, after reading blake's comments, will not hesitate to use it in bts. only two more weeks until i get my copy .

solver: so, ai seldom builds wonders or...it is just that there are less races?

[Solver]

Well, aggressive AI will still go for Wonders if they benefit it. You might find it easier to get a Wonder on that setting, but you'll fall behind militarily too much.

It's not that Aggressive AI doesn't build Wonders or culture buildings, it's just less likely to sit peacefully building such things if there is a nearby target that can be conquered.

[Will9]

Originally posted by vilemerchant
Anyone noticed the brilliant AI invasion strategy of sending a heap of units to one particular plot of your land, who then just fortify there and do absolutely nothing, until the war ends?

I've had the unload (we had open borders) all their troops on my continent and then declare war. Their stack of 25+ was sent to a one square island just of my coast ad 10 squares east of their landing site and their fleet just went back to their continent.

I have noticed the normal AI has gotten much weaker. I'll try moving up a level or agressive AI.

[Wiglaf]

The standard AI makes no sense.

When you click Play now, you expect the default civ experience. A competitive AI is a part of that. You are not selecting "Play Sandbox now" where you dictate the course of the game militarily. That is not civ, and never has been. This should be an optional setting, not the default.

And yes, there needs to be an AI patch on numerous levels. AI needs to better understand espionage, stop spamming corporations in its own cities, and quit doing dumb invasion tactics, such as
1) stationary stacks in borders and
2) attacking pointless spots with its whole army. eg, i've had an entire enemy stack wiped out trying to take down a hill with a mine on it fortified by 3 rifleman. why go for that mine and not the relatively undefended city nearby?

These are flaws from the BetterAI mod from January of 2007. The fact that they still exist suggests to me Firaxis just copy/pasted Blake's mod, with additional code for corporations and espionage, into BTS with little testing or modification. The same way they copied in the ethnic diverse units mod, the scenarios from the fans, etc.

[Solver]

Clicking Play Now should provide the experience that most people want. Most buyers, not most people here. I have never played a game through Play Now because I want full control of options. Any hardcore player is well capable of using Custom Game.

And interestingly, most buyers want an AI that can compete, but still allows them to dictate the course of the game. Most buyers want to win all or almost all the time, not have games where they fight tooth and nail to win.

I think that the majority of people who frequent Apolyton or any other Civ site would enjoy Aggressive AI because it's more competitive and tries harder to win. We have the luxury of using that.

[Wiglaf]

Try playing the standard AI. There are almost no wars. You almost have to beg the AI to declare on you. That is not civ. Civ games have been popular since Civ1. At what point do you think people buy these games because there are no wars? Wars have been in every civ game ever made.

If people want to win, they can set the difficulty lower. That way they can easily repel AI attacks.

[Solver]

I've played on standard AI most of the time, in fact. The amount of wars increases somewhat in BtS, but is still overall low. I rather prefer that to the Civ2 or Civ3 method, though. Civ4 AIs declare war when there are possible gains, not just for the sake of it. And if you ignore your military, civs that hate you still declare war.

But yeah, Aggressive AI is better. The best part of the difference, IMO, is that Aggressive AI has much stronger warmongering civs, ones that fight a lot and just attain a mammoth size eventually.

[Wiglaf]

Do you know if, after playing a custom game, those settings become the default for future Play Now games?

[Solver]

That's actually a good question. I know that they are remembered for your next Custom Game. Hmm.... I would guess yes, but that's just a guess. Please report here if you care to try it out.

[vilemerchant]

I don't believe it's ever been the case that custom settings of previous games effect the play now games. You can easily check by starting a game and clicking the fist symbol which will show any variations from standard in the settings.

[Wiglaf]

Well I just started a play now and it seems to have had the same settings as my last custom game. How do I verify that aggressive AI is on, though?

[Wiglaf]

Yeah, just confirmed -- changing custom game settings alters the default play now settings (map, speed, etc).

It does not, however, alter options like aggressive AI, tech brokering, etc.

Bummer

[Jaybe]

Originally posted by Wiglaf
How do I verify that aggressive AI is on, though?

F8: Game Settings tab

[Fidel]

does aggressive ai in bts result in slower ai teching? people report that even wussy ai in bts results in considerably slower teching (presumably due to even more rapid ai expansion and lower bonuses)?

[Nugog]

Originally posted by Solver
Most buyers want to win all or almost all the time, not have games where they fight tooth and nail to win.

I can sort of relate to this.

When I first got civ 4 (I used to play Civ 2 at a mates house while on all weekend benders.........) I wanted to win all the time.

Then I got bored - moved up a few levels and just got spanked. Kept trying, mastered those levels, moved up another one etc.

While I am still no where near the best (or even average) civ player here - some of my most enjoyable games have been the ones where I have been swearing away at the screen while some AI civ has torn through my carefully laid plans.

Losing can be fun, in a twisted sort of way.

I am not a "hard core" player - but this new aggressive AI sounds interesting - will give it a go - then retreat back to normal...........

[Solver]

I think you're a fine example of a casual player turning hardcore. As far as I remember your early posts, you were having problems with some of the simpler game aspects and were, generally, a casual player in every sense. In this time spent on Apolyton, you've really been turning into a hardcore guy, heck, you probably are one now, with all the time you spend here (see what Apolyton does to people? )

[ghen]

Most of my games I don't plan to win in any certain strategy, this leads to me basically either losing or winning by space race.. Alot of times I just turn space race off and just lose by score I prefer to not win the world but win my continent.

[marvinkosh]

I've noticed that the non-aggressive AIs will stay out of war if they can avoid it. This is a useful tactic to keep up in technology but doesn't do any good if the human player adopts an aggressive stance. That's not to say that they can't fight, but they don't have a deep enough reserve of units when they are invaded.

I guess it can't hurt to try the Aggressive setting, especially since I've been playing for conquest only.

[=DrJambo=]

I also don't start with a specific strategy in mind since invariably the map, starting position, or which random civ I'm selected to play, doesn't lend itself to accomplishing a set goal.

Culture victories are a fine example in that sometimes they just sort of fall into place. Either you get a lot of religions spread in your cities or you might get the required GP for the culture generating corp...

[Crossfire]

Is the standard AI on BTS less aggressive than Blake's AI mod for Warlords? Heck, I have been gang attacked on more than one occasion playing Warlords and am pretty much guaranteed to be attacked by at least one civ without selecting the Aggressive AI.