- "It may be difficult to secure your release."
- ―Count Dooku, to Obi-Wan Kenobi
A containment field was a device used to hold prisoners whose origins were on the planet on Geonosis, where its prototype was manufactured long before the Clone Wars. The field would be created and maintained by means of disk-like generators bolted to the floor and to the ceiling directly above in the room.
A detainee would hover over a meter, held inside the blue-colored field, and be required to wear magnetic cuffs that not only anchored the being in place but also monitored life signs, since a too-powerful field could stop one's heart or cause irreversible brain damage. In addition, the cuffs could be used as torture devices, capable of unleashing powerful electrical charges, and rotate the prisoner. Against Jedi, the field served to disrupt the captive's connection to the Force, preventing their escape.
Separatist leader Count Dooku used a Geonosian containment field to hold Obi-Wan Kenobi captive prior to the First Battle of Geonosis. Dooku attempted to sway the incapacitated Jedi over to the dark side of the Force, but Kenobi resisted Dooku's words and was sentenced to execution in the Petranaki arena.
The pirate king Hondo Ohnaka used containment fields to restrain his hostages, mostly notably doing so to Dooku and later Padawan Ahsoka Tano, when holding them for ransom. Tano tried to convince Ohnaka to release her, but Ohnaka responded by taunting her and refusing to give her anything to drink.