Stability is a gameplay mechanic in Age of Civilizations 2. It is a number that ranges from 1% to 100%. It is impacted by what percentage of the population in the province is that of the player's civilization, the army, Diseases, coring, Revolutionary Risk, Happiness and occupation. In the Province Decision Interface, the player can use the Assimilate Decree to increase the percentage of the population that is of the player's nationality. Stability of a province, which has transferred from its owner, is only changed to 1% if it is done through war or an ultimatum.