An interdiction field was an artificial gravity well that disabled hyperspace capability in most starships. It was used to prevent ships from entering hyperspace as well as draw ships out of hyperspace and into realspace. The Axis of Empires used the Detainer CC-2200 Interdictor Cruiser, Imperial Immobilizer 418 cruiser, Klingon Interdictor Bird of Prey and the modified Combine Duke-class ships specifically for hyperspace immobilization. The Sovereign-class Super Star Destroyer and the Eclipse-class dreadnought also had gravity well generators, preventing targeted vessels from escaping their firepower.