Surprising AI actions ?

[Innocentius]

I have a couple of battles that I remember where the AI surprised me, though in the opposite way.

First was a pretty basic example of AI stupidity: As the Burgundians (XL, late) I took Ile de France with a force much larger than the French one protecting it. They duly retreated, but sallied just the next year. As happens in Ile de France, I had a defensive bridge battle, the ideal setting. I won't go into details, but in short, the AI head on charge with most of their peak cavalry units except their king, got smashed by my Swiss halbardiers, Swiss pikemen and arbalesters. Then they just sent a force of some 600 (I counted ten units at least) of handgunners up the bridge, while their Chivalric Sergeants waited in the background (as they had came as reinfrocements). Well, handgunners ain't much of a problem. I took the opportunity, and started moving my Chiv Knights across the other bridge some distance away. Almost as soon as my knights have crossed, the French king rides onto the bridge were the battle is. I now have all the time in the world to manouver my knights, kill off the CSs from behind, trap the king on the bridge and annihalate the 600 handgunners. Result: about 150 dead for me, and some 1100 killed or captured on the French side, including the king.

Another two occured during my Bohemian campaign (XL Early, now scrapped). The Germans invaded Friesland, which was my weakest province as I had focused on producing ships rather than troops. Anyway, they out numbered me, and as Friesland goes into the plainsinland-maps, I though I was in for a tough defensive battle (I had mainly UMs).
Anyway, so the Germans move up their force, my army is standing close to the map edge with a forest protecting the rear. I move up my two units of Mounter Crossbowmen to flank the enemy. The enemy MCs, two units for them as well, ride up and a short archery duel take place. When three of their MCs are dead, and none of mine, the ride off. I can then move my MCs up to the enemy rear and start pepper their army from behind. To my surprise, they don't move. At all. They just stood there, with their army looking at mine and their MCs off somewhere else while my MCs peppered their best units (two units of FMAAs with armour +1). I thought this was boring and as it was exploiting the AI, I decided that I'd attack them once I had made maximum use of my MCs, ie. firing up all the bolts. Just when I start to move up my army to attack the attacker (which is really stupid, but it was really boring) the time runs out, and I win. 89 casualties on the enemy side, 0 on mine.

The other one took place in Friesland as well. This time I was technically the attacker, as an overwhelming German force had forced me to retreat to the castle.
Anyway, again, the setting is wooded plains. My entire army starts in a forest. I try to get my men up in position, then before I even leave the forest the entire AI cavalry, general and all, charges head on. I get my own cavalry out of the forest, while I move the rest of troops back inside. The cavalry gets into a fight with my Feudal Sergeants and FMAA, while my own cavalry rout the archers, UMs and single unit of spearmen that the AI has left unprotected.

[marcusbrutus]

In my game last week I attacked one of the pope's provinces, there was also a smallish Sicillian crusader army sitting in the province as they didn't have enough troops to attack me.

Anyway, it was a bridge battle and as I lined my troops up ready to cross the bridge I wondered why the AI was waiting so long to defend the other side.

What was happening was the Pope was marching across to the crusaders who he slaughtered! By this time all my troops were accross the bridge and ready to kill off the remaing papal army.

The worst thing is that the pope had called for the crusade in the first place.

[caravel]

They weren't allied, probably neutral, so when you made a battle there, it became a free for all for the province. As a result you've now put the Pope and the Sicilians at war with each other. Crusades just sitting in a neutral province are very vulnerable to this. I very nearly did the same in my current campaign (Almoravid/Early/Hard PoM), but the Spaniards and HRE struck an alliance the year before. I had waited for the defeated HRE crusade (to cordoba) in Castile to wear down to about 200 men, and then I had moved against the Spaniards there, expecting a free for all situation. I was surprised to see them allied, but ploughed through the HRE crusade and routed the Spaniards anyway. Next stop Leon, followed by Aragon. The Byzantine have bribed Navarra though.

[naut]

For me the AI surprises me with it's ability to never fall for my ambushes, ever! And it's persistence at being unreliable at bridge battles, one game it swarms me entirely another it is entirely incompetent (eg my English campaign were 2 Long-b, 2 Bill, 2 Chiv-K (dis), 2 Hob held a 1700 French army on a bridge and managed to win with not to painful a loss of men).

[caravel]

In the case of bridge battles, the AI, as you know, never attacks the second bridge, if it exists, allowing you an easy victory most of the time anyway, by sending a decoy holding force at the first bridge, backed up by the general (as the AI follows his position), and a faster cavalry/flanking force around to the second bridge. The answer to this exploit, not the best answer but probably the only one available, is to remove the double bridge maps. It's not as if you'd often find two bridges in that form in the real world anyway. Besides, the defender would have destroyed one, if not both, bridges in preparation.

[naut]

In the aforementioned battle of mine there was a second bridge, however to my damned bad luck I only noticed it after the battle was finished!

[Odin]

When I find the AI defending against a predomantely horse archer invasion force it often gives up superior ground. On more then one occassion i have used my mobile archer units to ride toward a defended hill whittle down some troops and hope to draw them into a pursuit.

The Ai will do this, but moves back eventually, yet if you continue to do this long enough the AI will eventually move its entire army from the hill to a less desirable position. On more then one occasion this has allowed me to get infantry up on one side of thier position and usually ends up with me gaining the higher ground.

Of note is, I dont play timed battles I have the timer off and I certainly dont rush. So maybe the Ai has a mechanism that caluclates the amount of time its in a position in correlation to the number of men you have vs thiers?

Dont know, but I have witnesses this enough that its noteworthy.

[Vladimir]

It's good to be the attacker. If you're defending the AI can pull off some nice flanking maneuvers and force you to respond to their actions. When attacking you still need to be careful. The game tends to use terrain wisely and it's a real pain to start off at a lower elevation.

I also like how when composing mostly "offensive" units (cavalry, good attack lightly armored troops) they go into offensive mode when defending. Cav and light infantry are horrible on the defense and can really disrupt your offense when they attack.

[marcusbrutus]

They weren't allied, probably neutral, so when you made a battle there, it became a free for all for the province. As a result you've now put the Pope and the Sicilians at war with each other.

I've never knew that, thanks Caravel.

The answer to this exploit, not the best answer but probably the only one available, is to remove the double bridge maps.

How do I remove maps?

Back to topic. On the harder difficulty settings in XL the AI can be quite difficult to beat unless I have a better army all round. Especially if the AI has a lot of cavalry - I have to keep my eyes on my army's flanks and rear all the time.