Rapture's defenses include automated turrets armed with one of three different weapons - a machine gun, a grenade launcher, or a flamethrower. Machine gun turrets are the most common, but luckily they will inflict the least amount of damage of the three. RPG turrets are less common than machine gun versions, but they pack a bigger punch and cause a significant amount of splash damage with their rocket-propelled grenades. Flame turrets let loose a stream of fire when approached, inflicting a considerable amount of damage and igniting any combustibles in their path. There are only a few flame turrets in the whole game, making them the rarest of the three.

All three turret versions can be hacked (thereby turning them against your enemies) and researched. There are five research levels that can be attained:

• Research Level 1: Increased Damage (+)
• Research Level 2: Twice as much Machine Gun ammo on destroyed Turrets.
• Research Level 3: Increased Damage (++)
• Research Level 4: Hacking Turrets is instant and automatic.
• Research Level 5: Increased Damage (+++)