Hmm in my opinion, You need a figurehead who can publicly speak and gain support of the people. Then you need to have a cause to rally behind to gain massive support. But a revolution can occur if a government isn't meeting the need of the people and they want to overthrow the government or a Coup d'état. But a revolution does not occur unless people want to set up a better life for themselves if the current system isn't working.
revolutions happen when two or more groups cannot come to terms within a normal decision making process traditional for a given political system, and simultaneously have enough resources to employ force in pursuing their goals.
