Plasmids are found, obtained, or bought with ADAM throughout the course of BioShock. Jack has a limited number of Plasmid Slots for actively equipped Plasmids, and his currently equipped Plasmids can be changed at a Gene Bank. The player may purchase additional slots and select Plasmids at a Gatherer's Garden. The player can purchase the third level versions of Plasmids without having the first two levels as a prerequisite.