Mob rule is sometimes called "ochlocracy" or "mobocracy". There is sometimes no legal government, and mobs of people decide whatever they want. It is government by a mob (crowd of people). In this system, the mob becomes the ruler or dominant force in society. Actually, it is rare for a whole country to be under mob rule. More frequent is for part of the country to overthrow its leaders and be for a time without a government. Parts of a country may try to secede (break off) from the country. That has been quite common in certain parts of the world.