I just started playing Civ IV again since they released BtS, and I decided to start at Prince. Almost instantly it became apparant that I could simply screw around, not manage my cities well, build whatever I felt like, and still maintain a score double that of the second-best civ. For a while (until the Middle Ages) I even had my capitol defended by a lone warrior. I thought the AI was supposed to be a little smarter, but I'm dominating this game even though I've been playing so carelessly.

Does the AI get any smarter at monarch or something? I'll move on to monarch once I get the chance to play around with corporations and the other new features on my current game.

Play with aggressive AIs on.

The AI is smarter and more diverse, but still stupid in quite a few ways. The biggest problems with the AI seems to be they often spend way too much on espionage and they tend to spam naval units. Once it gets to the modern age, it seems they do not know the difference between naval units and land units. They for some reason build even more destroyers and transports than they have land units.

A lot of peopel think it's gotten smarter, and some think dumber. There have been odd examples of both.

You're probably able to dominate so easily because the (paranoid) AI devotes money/to much money to espionage. Allowing you to steam ahead in tech (am i right?).

If you want a challenge click Agressive AI and flinch at the power of the AI and there mad armies and attacks.

The personality your facing also has a BIG effect, if you're the only neighbour of Shaka you will be in for a tough time, (he's now a uber-mad warmonger, but is fairly compotent at it which is worse.)

What's your play-style? Are you invading a lot, or are you building and teching? Also, what speed are you playing?

http://forums.civfanatics.com/showthread.php?t=235067
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It helps.

Does the AI get any smarter at monarch or something? I'll move on to monarch once I get the chance to play around with corporations and the other new features on my current game.

The AI is equally smart at all levels. The change in difficulty comes from varying AI bonuses/penalties, not change in intellignce.

Is it smarter than in vanilla Civ 4? That's arguable. It is certainly different, at in some aspects (such as warfare) it is definitely better. In areas such as tech pace though it actually seems somewhat worse (especially in Aggressive mode).

The AI is equally smart at all levels. The change in difficulty comes from varying AI bonuses/penalties, not change in intellignce.

Is it smarter than in vanilla Civ 4? That's arguable. It is certainly different, at in some aspects (such as warfare) it is definitely better. In areas such as tech pace though it actually seems somewhat worse (especially in Aggressive mode).

Honestly it's not debatable ho much AI has improved since Civ4.I have used Better AI since the first versions and the improvements are extraordinary and touches nearly any aspect of the game.
Vanilla civ4 AI was absymal in warfare, i remember that often you saw only stalemate wars where no city was captured.The city growth and the so called "industrial breakdown" has been fixed in BtS.There are also a lot other fields where AI has improved and i'm not mentioning.
Whether in Aggressive AI it techs slower, it's due to higher unit mainteinance, but you also often have a slower tech rate with this setting enabled.....if you set aggressive AI on you want to play a game more about survival than nation building so it's fair.

Hmmm, maybe I'll apply one of those patches. Thanks for your insight.

What's your play-style? Are you invading a lot, or are you building and teching? Also, what speed are you playing?

I fought an ancient war to conquer France, and now I'm just building and teching. I'm playing on epic.

I definately dont think all of the AI is more intelligent. In fact some of it is pretty amazingly stupid. I conquered bismark at 1200 AD with rifles emporer/marathon. He had only 8-10 cities, and yet still no alphabet/col until I gifted them to him as my vassal of 3 cities.
With a mediocre buddhist holy city (31gpt) he still was making no significant research progress, and also possesed a military roughly 1/3 the size of mine in unit count.

Also Ai doesn't prioritize rifling. Rifle men are what calvalry used to be in warlords, the end all kill all weapon against renaisance units.
In this same game I lost the liberalism race(didn't even attempt due to wartime spendings). After researching democracy,corporation, and all that fancy stuff the race winner(hammarabi) decided that longbows were still sufficient. Needless to say one look at the power chart and babylon, was a new province of the maya empire,within 10 turns of the war with bismark.

The AI also expands poorly (even with solver's patch). I frequently see the AI's not building their SECOND city until 2000 - 1500 BC, which is around the time I have my third or am planning a fourth. This is with aggressive AI, so the AI is booming chariots/archers/other trivial ancient stuff and refusing to expand. I don't know what the deal is.

AI is different, that doesn't mean it has become more ''inteligent''.I never show AI doing something ''smart'' during war time, it doesn't have a plan and very often it sucrifises it's units with no reason, it doesn't benefit from terrain bonuses and it makes suicide attacks versus cities with units that do not have a chance.It stacks large amount of units that remain immobilized or exposed to enemy units, so my conclusion is that strategicaly speaking it is not a ''smart'' AI.

It now knows how to collect its units into a stack, and attacks with said stacks. Therefore it "appears" to be smarter. It doesn't really seem to care whether the whole stack gets annihilated though, and will basically do the same thing again.

Harsh, but true Im afraid.

Huge staks of units doesn't help, i never(i immagine most players)stack all of my units in one great army,i always try to attack with more stacks, i mean if i have a large amount of units i don't send them all together but i try to make a combined attack,one stack attack a city and the other attack the enemy units or attack two cities at the same time,at my current game i attacked AI with for different stacks from three different locations.
Also i never show AI using marines to take over a coastal city or an island, so i agree that AI is improoved but not in the way it sould be,because the game offers a great variety of units that cannot simply get stacked in an army and march.
AI depends on it's quantity of units not on it's qualities and certainly not on a more sofisticated combat system.