Ive noticed this too.  I have to defend my cities and units, but the Sov AI can send out pioneers with no fear, and yet mine have to be guarded along with my cities.  I have yet to see a Sov city defend itself from mobs that wander around, and yet I have lost cities to them.  I even saw one Sov city, with mobs surrounding it..and nothing.  I think the AI for mobs, should be tweaked so they go after everyone.  ONe think I love with raging barbs in Civ 5 is that...they attack them as well as me.

I believe that changes based on difficulty settings, i have seen Magnar clean out Morians place and settle it without killing any stacks and without having his cities destroyed on normal/normal but right now playing challenging/challenging and i have seen several ai cities and outposts destroyed by rampaging monsters.

Playing on hard difficulty dense monsters, I've noticed the monsters do occasionally attack the AI, but it is pretty rare. Despite the many posts of the devs that they treat AI and player alike it isn't my observation. I've taken over AI cities that have lived their entire life next to a monster lair, and the turn after I take it over they decide to attack, bc it is my city- I've taken to clearing the monsters around the AI cities before I take the city and move on. 

An interesting note about the Tarth- the monsters never felt like they were specifically targeting me, but did sometimes randomly wander into my cities- which is why I don't like their stealth trait too unreliable- sooner or later you will end up fighting them anyways.

The biggest issue I have with monsters is the randomness of it all. I can build warden but they don't always work, and rarely work on the scary stuff my defenders can't handle. I'd much rather monsters have defined territory they defend. If I enter their land or single square they attack immediately rather than circling my  city for 10 to 20 turns, apparently working up an appetite, and then suddenly deciding to eating my city.

Glad We are talking about this issue. IMO it is one of the most important bug to adress in order to iron up the gameplay experience IG.

I've encountered this bug in every version of FE and LH so far. Sometimes it does not bear major consequences apart from a gamebreaking bug which should cost one or the other stack of monster&ruffians or AI' army. On other times though, it really ruins the gameplay. For instance I had an issue were a friendly AI caravan was following the same path as a stack of an enemy AI's army, making it impossible to attack their the enemy army until they reached one of my city.

Here is an exemple of this bug:

Notice how both army perfectly stacks.

Now onto what feels like the most pressing matter right now: AI intelligence and AI city placement, because when I read this:

I feel really alarmed. NO! The AI still massively benefits from a game breaking immunity from monsters in general. Settling near Dragons, Haunters, drakes and such monsters one or two tiles away from their lair and still DO NOT getting attacked. I'm not saying they NEVER get attacked, which is salvaging the game experience a bit, but you just can't let the AI get away with this any longer!!! In over 50 hours of LH I still have witnessed on countless occasions stacks of monsters wandering away from their lair and NEVER attacking the AI city, sometimes even wandering into my lands. And in maybe a couple of instances have I seen an AI settlement getting attacked and destroyed by monsters (proportion feels like 95% immunity to 5% aggro from monsters, which should be the other way around).

The worst part being when you cap these settlements now these deadly groups turns onto you the turn you take the city, which really adds insult to injury. Now you have to deal with that Fell Dragon or you know... it's gonna burn the last 2 city you have capped and probably cut off your reinforcments.

A monster getting driven away by the creation fo an outpost or the border expansion of a city NEEDS TO automatically turn onto the player, being AI or human that has awaken him. And don't give me this "it's normal if you play at higher difficulty that the AI gets a preferential treatment". NO! Monsters are neutral and should act as such. If you want them to be much more aggressive towards the human player fine, but a same rule must exist when monsters are awaken by the AI and by us.

• This means working on the AI to make it choose better locations for settling cities and taking into consideration its border expansion according to the type of settlements it wants to make ( at least 3 to 4 squares for towns, 2-3 for conclaves and 2 for fortresses).

• If you want to give the AI an advantage, you could make the monsters wander for a few turns to let the AI create some defending troops or bringing troops to garrison, but after 10 turns these outposts needs to burn and these settlements needs to be targetted.

• Maybe associating the AI from clearing a certain area for expansion could be coupled with another bug fix, which is that the AI still rarely picks up the loot from the encampments it clears. Adressing these issues would make the game look much much more solid from a gameplay POV.

Edit:

It seems to me that when you get vision of the AI settlements or troops/ then the monsters and ruffians turns more aggressivly on them, but that might just be me.

i.e: had an instance where a neighbour created a settlement 2 square away from a haunter's army. Settlement grew to town, expanding its borders 2-3 times and stayed safe for ~70 turns. When I started to move units to stack up in view of the city (and the wandering haunter's army), the monsters were suddenly driven towards the AI town. In 5 turns their city was in ashes while I still was waiting for a couple more troops.

I have recently had a few games where my own cities are rarely if ever attacked. When they do, only 2 weak defenders and no militia instead of my full roster of units in town are "called to fight".

I was "pinned" in my cities, waiting for monsters to walk away or attack because I overexpanded and had no gold to make more units.

When the enemies attacked me, I didn't even get to protect myself. I had 5 units in the city, and 2 of them (mirror elementals) were allowed to fight while my Wraith Knight and 2 Spiders were left  out of battle.

I don't know what kind of monsters suicide to your militia, but in ridiculous/ridiculous, whenever something attacks my cities, militias don't last too long. Note that I'm extremely careful about city placement.

Pure contradiction. Even with the manipulation in your game files. Depending on your starting location, monsters present a moderate to a serious threat every game, at least from my experience, in expert+ on both settings.

1) If you pay attention to power rating, whenever AI factions undergo a drop they lose military units/cities. You can more or less quantify their loss by comparing the previous and new faction strength. It is a very useful indication, even in areas that you can't totally scout.

2) Heavy scouting let you know where and when AI cities are settled or destroyed, giving you a pretty good idea again of what's going on. Now when you compare the number of cities destroyed by monsters, to the numbers of cities they get away with, settling near monsters they couldn't handly in the first place (or would need to creep first to settle), you just can't deny what's obvious.

Just look at the number of times these problems have been posted on the forums, either for FE or LH. Yet no solution has been reached and the subject has hardly been adressed in the successive patches. Note that the same thing could be said for the Book of mastery tech/SoM victory.

As stated above, everytime the AI or yourself loose troops, it/you drop points in power rating. If this faction is not at war then the loss can only come from monsters.

I only have recently started to take screenshots to exemplify my points. I'm afraid that for the time being I don't have any clearer screenshots for the second and main problem which we discuss right now, although the 1st problem concerning the stacking of monsters with AI units is not to be forgotten. Concerning the 2nd issue, Look at the exemple I give in the Edit of my 1st post (unfortunatly didn't screenshot it) but that was during a V0.51 game of LH...

Another exemple of AI&Monsters stacking from FE in december. Note that before moving on the same tile, this pioneer stationned a turn on the desert tile near to the skath in complete safety. (Yes, yes I know so much for my heavy scouting during this game, but it was my 1st try in Ridiculous/ridiculous, with a custom faction I used for the 1st time. Bull rush was not very effective... )

What I do have is easily over 300 hours of playing in both FE and LH (first 2 games were hard and challenging the rest in expert & ridiculous, using the same difficulty each time for monsters and AI). Always using multiple scouts in every game (double scout is in my BO in the first few turns lately), I can safely affirm what I put forward in my aferomentionned statements.

Have a look around in the forums and look how many posts concerning the behaviour of monsters towards the AI have been made. I think the December patch tackled very few issues concerning this problem, changing the situation to "almost total immunity" to "somewhat/situational immunity" to monsters.

Yes I've witnessed this pop up when a clusmy AI gets wiped out early by settling in a risky location on rare occasions. Strangely enough (or not) this seems to always happen very early game, as in if the AI awaken a deadly threat with its very first settlement.

My point is that the AI, most importantly, needs to make better choice in its settlements location as well as creeping the monsters and taking their loot if it wants a dangerous city location.

I've had one game with 3 such messages.

Also, I did some testing of my own of this matter. In fact I had even provided savegame where a troll army is just about to attack and raze my city. I made the save by spotting trolls approach a town with no troops in it, then passed few turns with me doing nothing about it, and just when they reached it I made a save. I tested the save at least dozen of times by reloading and pressing end turn to see if they will attack the city and they did it 100% of the time. Not even once did they not attack. Then I loaded my normal save and placed my sovereign in that city. He reached it just before the monsters would attack. Instead of attacking the city, they wondered off. In fact they left my territory completely.

I had an event where spider queen unleashed her armies to the world it that same game, not long after the save. It spawned queen herself close to my main research city, one huge group (9) of corpse spiders right next to my capitol (1 tile away) and another such group not far from my main fort city close to my outposts I had there. I had no chance to killing those corpse spider groups with anything I had in that moment. However, I did place army and heroes in my capitol and the spiders did not attack. They were wondering around the city for more then 50 seasons, razed one of my outposts, but never attacked or moved away far from the city. I was literally under siege from that corpse spider army for almost 50 seasons. Fortunately, I had developed better weapons and groups for my armies and when they finally attacked I managed to kill them. Apparently, just having defense was enough for make spiders not attack my capitol. Btw, I managed to kill second group of spiders by using that army and UPGRADING my outpost to give me attack and defense bonus. Shows how these upgrades can be very useful once in a while.

I have seen some games where AI would be completely RAVAGED by monsters. For example, Magnar who was my neighbor made second city, then lost it to monsters, then made another city, then he lost his capitol to monsters and only had that one small city he founded for the most of the game.

Saying that monsters don't attack AI is simply not true. Why do they seem to attack players more then AI? You can see a clue to that if you inspect AI cities (you do scout right?). AI will rarely if ever have no troops in the city. Monster apparently check if the city is defended (and probably how well it is defended) and if it has good defense, they almost never attack. Try making some combat units, and garrison your cities there and you will see that monsters won't attack you very often. They do, in fact sometimes attack even then, but it's very very rare. It may be a reason why some people see monsters attack only them, and no AI's. AI's have troops in those cities, you don't.

Tavra- I've seen similar dances around my undefended cities. Obsidian golems are in my territory, then not, then 5 turns later they are back. Nontheless, Daynarr could still have a point. In my experience, undefended cities seem more likely to be attacked. 

If we want to take our experiences in the game and consider them THE MOST ACCURATE PERSPECTIVE PERIOD, there will be no constructive discussion on this topic. I have between 300 and 400 in the game. Sometimes it REALLY seems like the monsters prefer me as a target over everything else. But if you understand the failings of the availability heuristic...

http://en.wikipedia.org/wiki/Availability_bias

...then you can't be SURE how the AI works. To be sure, you'll need to play for 400 hours with 100 scouts, and keep an extensive log of game data.

Frogboy has stated that it is random (I'll see if I can dig up the forum post). There is likely some weighting to this randomness (MORE chance to attack players, perhaps, or more chance to attack undefended cities).

My opinion is that the system, as far as monsters are concerned, is fine as is (well the swarm mechanic might completely change my mind there, but jury is still out). You don't have to agree, but let's avoid getting nasty over it.  

I think it it is tied to difficulty settings and garrison strength along with random but, in my experience on lower difficulties you are more likely to see monsters not attacking ai settlements and units.

Basically on easy monster difficulty the monsters don't attack your cities, perhaps there is a modifier to the random chance that makes the monsters less likely to attack the ai thus on normal the ai might still have the easy ruleset while challenging would cause the monsters to start attacking the ai.  Just speculating though.

You are aware that the AI gets a massive advantage on ridiculous right? The more you ramp up their difficulty the less they have to worry about monsters. This is obviously intentional. I usually play on challenging AI with normal-hard monsters, my militia can handle the vast majority of monster attacks on my city that happen (usually just a random bear cub or some mites). What I modded in my example was only the number of lairs, not their strength, so it took the normal tendency for monsters to attack and doubled it, meaning the AI was being attacked so often it couldn't recover or expand and just crumbled beneath the monsters. Clearly they are not at all safe from monster attacks, even in areas of the map you haven't scouted.
 

That tells you what exactly? I have over 40 hours played in this LH beta and I have not lost a single city to a monster attack. Not one. I have not had to reload or anything. I have seen many AI cities razed by monsters, even on non-modded game settings (with challenging AI). So by that logic there's a heavy bias for monsters to attack AI cities instead of player cities, right?

Also the AIs are pretty much always at war with each other, their power levels fluctuate every turn, they lose battles and cities to each other very often, trying to gain any information about monster attacks from that is futile.