Deck Twelve was a chamber inside the Megalox space station that contained the primary security field generator that projected the gravity shield above Megalox prison on the planet Megalox Beta. During the Mission to Megalox Beta, several Resistance astromech droids including BB-8, O-R10N, R2-HA, and R4 breached the chamber in order to deactivate the gravity shield and help Poe Dameron and Black Squadron rescue Grakkus the Hutt.