A Force Wave, which can also be called a Force pulse, was an occurrence tied to the Force. The Fermata Cage's destruction between 3 ABY and 4 ABY resulted in the emanation of a Force wave that then propagated throughout the galaxy. As it expanded, Darth Sidious observed a weakening of his command over the Force. Upon the wave's return later on, it generated a significant disturbance in the Force, leading to both Sly Moore and Darth Vader experiencing a loss of control over their Force abilities, with Vader causing widespread destruction in his vicinity. Nevertheless, Sidious, leveraging his substantial power within the Force, successfully reasserted his dominance. Vader eventually regained his mastery of the Force during a skirmish with the Scourge, concentrating his efforts by channeling his hatred, specifically his self-loathing, to sharpen his skills.