I like that^

It's savescuming but not strictly cheating.

Save scumming is when you make a backup of a save in a game that deletes saves after you die, then restoring the save from your backup when you do die. Using the normal save and load mechanics of a game is not save scumming.

I think the best (easy) solution would be similar to what many people are saying.  Most creatures would kill population and destroy some buildings while only the really large ones, like dragons, would destroy the entire city outright.  Basically, the stronger the creature, the more damage done.

However, what I'd really like to see is a little more variety.

Animals and other less intelligent creatures would act more instinctively and, basically, leave the player alone in most cases.  There's really no reason a bear should be going in to attack a city.

More aggressive creatures, though, should be more aggressive and attack the player / AI more often.  This is especially true if, say, the player builds near their lair.  These types of creatures would then be much more likely to come attack.

Finally, more intelligent creatures may come attack and attempt to capture cities.  They would then build up forces and try to capture other nearby cities.

I think something like this would change the dynamic a bit and make for a more interesting game.

I rather like the idea that the level of the city should determine the outcome vs basically unintelligent monsters excluding dragons and high level creatures.

lvl 1 destroyed 

lvl 2 random # of buildings destroyed no loss of city, random chance city destroyed

lvl 3 2 buildings destroyed no loss of city

lvl 4 1 building destroyed and x # of population no loss of city

lvl 5 loss of population no  loss of city.

Now of course if an army from another faction captures the city then there are no restrictions. An army would be able to destroy a level 1-5 city poof 1 turn.

I think a simple system where monsters reduce the population of a city is best, with higher level monsters doing more damage and maybe even destroying a random improvement. The monster would then wander off and not attack that city for x turns. Also monsters could haunt resources, ie  instead of wandering around forever they could attach themselves to a mine or something and deny players the resources from it.

This would lead to more interesting situations where dragons could wander around and terrorize kingdoms without it being a complete 100% game over.  It would give you time to build up an army to drive them out. Other factions could even ask you to kill monsters terrorizing them. There would be so much more depth and immersion to a system like this.

For those of you who like tough monsters this would still be a good thing because it would allow them to re-add stronger more aggressive monsters. Since the days of early FE monsters have actually been neutered quite a bit. There are very few wanderers before mid-late game. Also right now tough monsters ignore cities most the time early game because they would be unstoppable early game. You would actually be dealing with monsters all the time instead of ignoring them.

I am in favor of just about anything that's been suggested here, or in the many other threads requesting a change.  It's bad enough that you can't see a single tile beyond your ZoC, so early game you can have monsters just show up one turn shouting "Surprise!" and razing your city the next.  But it's also bad that fairly early game you can, through no fault of your own, have deadly monster armies wandering your territory.  Even if you stationed all your units in the one town they attacked, you don't have a chance against them.  You basically lose the game on a die roll. 

So, yeah, monsters shouldn't be insta-razing cities.

I like the idea that monsters don't raze the city, but rather 'raid' it.  Bandits would get food, supplies, better weapons, armor, entertainments(morale, levels), and new recruits.  Settlement looses some pop and maybe some infrastructure.  Beasts, etc., go to town for some shopping and dinner (pop).  They leave with higher level, maybe a few new 'youngins.'  After a successful raid - thay go back to surrounding area and roam...   City owner has a damaged city, and (perhaps) time to restore order...

Everyone is throwing out great ideas, I really like the event-based ones, those could be very promising. I still don't see the problem people have been talking about. I've only lost one city to monsters in 98 hours. The only monsters that seem to actually attack my cities are Bone Ogre armies. The one city that I did lose was hit by Bone Ogres early game and they just steamrolled my hero and defenders right into a game over screen. Rock spiders don't seem to leave their lairs, neither do bears. And if they did with the exception of Cave Bears I think the militia could handle bears or rock spiders. So I dunno, I guess if it happened a lot more often in my games I would agree. But as it is it's rare and it always seems to be Bone Ogres that try it and I can usually kill them in the siege. One thing monsters do often tho is destroy my improvements. I love it and I hate it when they do that. But it does keep me on my toes because if a monster can get at an improvement a full-blown enemy army could just as likely do the same. So I try to keep a few defensive armies On Call

Maybe I am just too good at going around the country side slaying monsters and clearing their lairs? I can easily imagine how the world would get out of hand if I didn't clear them out every chance I got.

Edit: I am going to try a game where I am less zealous about clearing out monster lairs, and I bet I will be back on the boards in a few hours agreeing with everyone whole-heartedly

Everytime people kept talking about Dragons destroying cities all I kept thinking about was the Hobbit! You read my mind parrotmath, now we just need 13 Dwarves.

This I suspect is to counter the spell of making... I wouldn't want to lose that spell, because I might not be able to reach that city in time with my army, but the spell I can cast to stop the progress

So, read some of the posts, all thoughts about cheating aside..... monsters destroying cities is silly most of the time, and annoying almost all the time.  Sometimes there will be strong monsters near all (or at least most) of your expansion locations, and they will go to town on your cities.  It would be much less frustrating if A-  the cite could still function, in a  reduced capacity, for a while, or at least B-  If every square that was part of the citie wasn't salted.....

Maybe pay a gold fee for repairs, and lose population?  The bigger the city, the bigger the gold fee would be?  (If someone already suggested that, sorry for redundancy).

I don't see why it is a game braking problem?

If you don't want city's burned to the ground then defend them, it is exactly the same as colonising during a war.