The Battle of Slag's Pit occurred circa 19 BBY at the location known as Slag's Pit during the period of the Clone Wars. The Galactic Republic troops were under the command of a general who planned to utilize demolitions to collapse a Separatist stronghold. Despite warnings from Skelly, a soldier and explosives expert, who argued that the ground's instability and the unsuitability of the explosives made the plan dangerous, the general ignored these concerns and gave the order to attack. Motivated by a desire to protect his comrades with his natural skills, Skelly chose to personally enter the breach himself. Tragically, Skelly fell into a coma, and all of his fellow soldiers died during the assault.
Upon awakening from his coma after the ended Clone Wars, Skelly discovered he had lost his right arm as a result of the failed operation. Because the medical droids had exhausted their supply of human-compatible cybernetic components, Skelly was fitted with a prosthetic limb intended for Klatooinians, which was incompatible with his physiology. The flawed surgery left Skelly permanently burdened with the malfunctioning prosthetic, with no possibility of replacement.
John Jackson Miller's 2014 novel, A New Dawn, includes a reference to the Battle of Slag's Pit. Miller has commented that the Battle of Slag's Pit serves as the Clone Wars parallel to the Battle of the Crater from the American Civil War's.