But since you invited other suggestions for improving the game, I thought I'd take advantage of it

This is something I wrote quite some time ago but never bothered to post because I figured no-one would ever read or care about it. It's basically an idea for making happiness levels more volatile, and then tying rebel appearance and some other game mechanics to happiness levels. These ideas, BTW, are also based on the system in LOTRII, but in a more simplified form. Here they are:

Seasonal Random Events.

I suggest a random event for every province every turn, affecting the province's happiness. Some random events would be positive, some negative. And you could have both major and minor random events. A major random event would add + or - 20% happiness to a province, depending on whether it was a good or bad event. Minor events would likewise add + or - 10%. Minor random events would occur more frequently than major ones. The effects of random events on a city's happiness are cumulative, except that happiness can never fall below, say, 30%, or go above 170%.

Types of Random Events.

Minor positive random events might include good harvest, good weather, good omens, good trading - whatever. Minor bad random events might be bad harvest, bad weather, domestic animal disease etc.

Major positive random events could be excellent harvest, excellent trading and so on. Major negatives might be plague, failed harvest etc.

A battlefield victory or defeat in a nearby province might be a good or bad minor event. Retraining units in a province would also be a minor bad event, as would recruiting, results applied cumulatively. Maybe recruiting in a smaller town would be a major bad event.

Contested Provinces.

In addition, I think contested provinces - that is provinces containing units from two or more warring factions - should get a flat -10% population growth plus 0 gold for the duration they are contested. (To that, incidentally, I think there should also be an initial -10% happiness adjustment when an uncontested province first becomes contested).

Provinces contested by rebels rather than an enemy faction only get -5% population growth instead of -10%.

Happiness and Rebellions.

Which brings me to the subject in mind - rebels. Right now, their appearance is totally random. How about linking their appearance with some other factor in the game - like a province's happiness for example? Here's one way it could be done.
The idea is to make a province's happiness levels more volatile due to the effects of random events described above, and then to spawn rebels based on the happiness level. (BTW this mechanic would replace not only the mechanic that currently randomly spawns rebel armies, but also the one that spawns rebellions *inside* cities when happiness falls too low).

So I suggest that the probability of a rebel army spawning is simply equal to the percentage that a city's happiness is below 100%. So 90% happiness = 10% probability of a rebel army spawn, 70% happiness = 30% chance and so on. Once a rebel army spawns, no further rebel armies can be spawned in that province regardless of happiness level until all rebels in the province are eliminated. But the spawning of a rebel army is itself considered a negative random event, subtracting 10% happiness from the province. However, the elimination of all rebels in the province is regarded as a major positive random event, immediately adding 20% happiness.

Here's an example. You have a province that has dropped to 60% happiness and spawned a rebel army, so it drops a further 10% to 50%. You don't get any cash in the province and have a -5% population growth factor cumulative with the other pop. growth factors until the rebels are eliminated.

So you immediately send out an army to eliminate the rebels. You eliminate them, which counts as a major positive event, so the province happiness goes from 50% to 70%. Unfortunately it is still 30% below 100% so there is a 30% chance of another rebel spawn next turn. This happens, so you still aren't getting any money from the province. You manage to beat that army too and get another +20% happiness for the elimination to take the total to 90%. Fortunately you don't spawn another rebel army next turn and have a minor happiness event, which takes you back to 100% happiness.

It sounds complicated, but really it isn't, and instead of the AI just spawning armies randomly, you now have a mechanism for it, you can see which provinces are most likely to spawn rebels, and perhaps be able to do something to prevent it (like lowering taxes or increasing the garrison). On the other side of the coin, positive random events also give you the chance to increase your taxation level from turn to turn. So on the whole these changes should add some more interest to the management of your provinces, without necessiting more micromanagement (since you have to check tax levels and happiness practically every turn in the game as it is anyhow).

Size of Rebel Armies.

One further point. I haven't described a mechanism for determining the *size* of spawned rebel armies yet. Here's one suggestion - a random number between 1-3 units, multiplied by the magnitude of the province's current unhappiness level divided by 10. So 10% unhappiness (ie 90% happiness) will spawn between 1 and 3 units. 20% unhappiness (80% happiness) will spawn between 2 and 6, right down to 70% unhappiness (the maximum) which will spawn between 7 and 21 units.

Also for every turn the rebels are not eliminated and the province's happiness remains below 100%, anywhere from 1 to 3 additional rebel units are spawned in that province. In effect, the longer you leave it to tackle the rebels, the more of them you will ultimately have to deal with. If you leave it until they have a substantial army, they may even besiege your city and end up taking the province. And to make it more interesting still, perhaps that province should then revert to the faction that originally held it!

Anyhow, here's a quick summary of how the system would work on a turn by turn basis:

Turn 1.

City A ended last turn with 100% happiness. Gets a "poor harvest" minor negative event at start of this turn. Happiness immediately reduced -10% to 90%.

Test for rebel spawn at 10% probability (100 minus happiness level ie 100-90=10). Spawn fails. Continue game.



Turn 2.

City A now has 90% happiness. Gets a "cattle disease" minor negative event. Happiness down 10% to 80%.

Test for rebel spawn at 20% probability (100 minus 80 happiness = 20% prob). Spawn fails. Continue game.

Turn 3.

City A has 80% happiness. Gets "failed harvest" MAJOR negative event. Happiness down 20% to 60%.

Test for rebel spawn at 40% (100 - 60). Spawn succeeds!

Successful spawn means -10% happiness event generated. Province happiness now 50%.

Test for size of spawned army. A random number between 1 and 3, multiplied by province unhappiness/10. The random number is 2 and it's multiplied by the unhappiness level/10, in this case 50/10=5, so 2*5=10 rebel units are spawned.

Contested province means no gold from this province this turn. -5% population growth.

Turn 4.

City A has 50% happiness. Gets a "baby boom" positive minor event. +10% happiness, happiness goes to 60%.

Province still returns 0 gold and -5% population growth for presence of rebels.

Rebel army still exists so test for 1-3 unit increase. Gets an additional two rebel units, rebels now have 12 units.

Friendly units attack rebel army and eliminate it. MAJOR positive event immediately generated, province happiness up 20% to 70%.

Turn 5.

Province A has 70% happiness. Gets a "positive prophecy" minor positive event. +10% happiness so province has 80% happiness.

Test for rebel spawn at 20% probability. Unfortunately, spawn succeeds again. Size of rebel army again is INT((RND*3)*unhappiness/10), RND returns a 2.5 so it's 2.5*20/10, or 5 units spawned. -10 unhappiness event generated, happiness level to 70%.

And so on. The basic idea is to make it critical to keep happiness at or above 100%, and to deal with rebellions quickly and effectively lest they blow out of control and ruin your province over a number of turns. It should also make the management of provinces an important part of the game, instead of the unexciting chore it is now. It also makes the number of rebels you face partly dependent on your own management skills instead of just being a totally random occurrence as it is now. IMO, games should always be about mastering a set of skills, not merely throwing random events your way for you to deal with.