Big Daddies are hulking, genetically altered protectors clad in pressurized diving suits, tasked with guarding Little Sisters—genetically modified children who harvest ADAM from corpses in the crumbling underwater city of Rapture. This symbiotic relationship forms the emotional and tactical core of the BioShock series. While the Little Sisters represent the tragic cost of the city's corruption, their fearsome guardians act as relentless, heavy-hitting machines of war, reacting violently to anyone who threatens their small, vulnerable charges.
