An Automated Defense System was a defense computer program, using any combination of laser cannons, turbolasers, or other weapons to defend a ship, space station or planetary fortress from attack without the need of a manual controller. They could be routed through to exterior weapons to defend against enemy vessels or vehicles, or interior automatic turrets to defend against infiltrating soldiers.
Exterior Automated Defense Systems were in use before the New Sith Wars, but the programming was basic and could only follow predictable attack patterns. Most pilots could predict after one or two runs and overcome with minimal difficulty. As a result, manually operated lasers were preferred and became the norm, as an operator could match a pilot's unpredictability whereas these early systems could not.
One such system was that defending the fortress of Belia Darzu on the legendary dark side planet of Tython. When Darth Bane traveled to the world seeking Darzu's knowledge of constructing Sith holocrons, he was attacked by a pair of laser turrets working on one such system. Evading the initial attacks, Bane noticed the turrets followed an identical attack pattern as the first attempt to shoot him down on his second pass. Avoiding the turrets predictable fire, he decimated the two towers.
Due to the restricted space inside a fortress or ship, Interior defense systems were used to a much wider extent, including inside capital starships as used during the Clone Wars and the Galactic Civil War.