A disturbance in the Force, referred to as echoes in the Force by exiled Jedi and former Sith Kreia, was an unusual fluctuation or anomaly in the Force that could be sensed by Force-sensitives. These disturbances could range in intensity from mild fluctuations to full-blown psychic trauma that would cause the individual to experience literal, physical pain and perhaps even mental shock.
Types of disturbances
Wounds in the Force were the most easily recognizable form of disturbance. Such massive disturbances were created from the most catastrophic events of death and destruction. Force adepts could often feel such disturbances from across the galaxy. Darth Sidious had managed to trace Darth Maul and Savage Opress' location on Mandalore via a disturbance in the Force, resulting in him traveling to Mandalore to personally confront the two Sith Nightbrothers.
While death caused the greatest ripples in the Force, many other developments in the Force caused disturbances such as alignment shifts. One such disturbance was sensed by Master Luke Skywalker when he no longer felt the dark side aura around the Massassi Temple and, years earlier, when he felt great power coming from a cave during his training on Dagobah. In 9 ABY, Leia Organa Solo sensed this when she passed through the place in orbit around Endor where Emperor Palpatine had died. Luke and Mara Jade also sensed this in his former palace. In the aftermath of the Battle of Hoth, Palpatine sensed a disturbance in the Force from Luke Skywalker's Jedi potential, and demanded that Darth Vader, who had also felt it, make contact with him on the matter.
The dark side of the Force often created disturbances—during the final years of the Mandalorian Wars, the Jedi Malak felt great amounts of power coming from the inside of the Rakatan ruins on Dantooine, stating that "he could feel its power". Almost a decade later, Kreia felt the dark side aura emanating from Korriban and she refused to even set foot on the planet's surface when Meetra Surik traveled there.
Disturbances in the Force caused by the dark side often had powerful effects on surrounding flora and fauna. When the Jedi Padawan Juhani briefly turned to the dark side, she drove the Kath hounds on Dantooine mad—causing them to become extremely aggressive and violent. The fractured planet Malachor V was so corrupted with the dark side that it affected the life on its surface—namely, the Storm beasts. Another creature corrupted by the dark side was the Terentatek. The power and presence of the dark side gradually distorted their shapes and corrupted their minds. As a side effect, terentatek became virtually immune to the effects of the Force.
Other disturbances may occur during unnatural events in the Force. One such event occurred when Kyle Katarn first felt the power of the Reborn warriors. After his first duel with one of the Reborn, he remarked that his encounter with the warrior felt strange. He stated that the Reborn looked like a Jedi and fought like a Jedi, but that his power felt warped. The Reborn and the Shadowtroopers were Dark Jedi that had been artificially infused with the Force. As such, when a Force adept came near them, they could feel the abnormality of their power.
- Star Wars: The Roleplaying Game
- Star Wars: The Roleplaying Game, Second Edition
- Star Wars Galaxies Trading Card Game – The Price of Victory (Card: Disturbance) (backup link)
- Star Wars: The Card Game – Core Set (Card: A Disturbance in the Force)
- Star Wars: Edge of the Empire Core Rulebook
- Star Wars: Age of Rebellion Core Rulebook