Happiness is one of the variables of provinces of Age of Civilization 2.
Increases tax income: happy people are more likely to pay taxes.
When happiness is very low or 0, province stability will decrease. Consequently, the rebellion risk will increase.
Possible way of alternation
Organizing a festival in a province will increase the happiness of that province. This can be done by Selecting a Province >> More >> Festival (in the Decrees Panel). This will cost money and movement points, the amount depending on the province. It lasts 7 turns, and happiness gradually increases happiness during that time.
Each government type consist of a “Tax threshold”. Once the tax rate exceed the threshold, the happiness of all province will decrease according to the rate of exceed. Conversely, if the tax rate is below the threshold, the happiness will increase in a same way.
If a province is raided, it happiness will decrease according to the scale of the rate.
Change of capital:
When one change the capital, the happiness of the original capital decreases, while the happiness of the new capital increases.