The tipping point for regime change arrives suddenly and is difficult to predict, even by those leading the revolution, as well as those leading the defense of the ruling regime. For example, at the time of regime collapse in Russia in 1917, Lenin was in Switzerland, Trotsky was in America, and Stalin was in Siberia. Like a dam that suddenly bursts as a result of the addition of a few more small drops of water, the exact moment of regime collapse is difficult to predict - even by leaders in the revolutionary movement and the forces defending the ruling regime. However, the destruction that follows the bursting of the dam is predictable. Three factors are proposed as preparing the ground for regime collapse. First, societal changes, which can be subtle, incremental, and long term. Second, changes in the ruling elite, particularly with respect to cohesion and fragmentation. Third, the emergence of a charismatic leader who takes charge of the revolutionary movement, often opportunistically putting themselves at the front of the movement.