BioShock is set in 1960. The player guides the protagonist, Jack, after his airplane crashes in the ocean near the bathysphere terminus that leads to the underwater city of Rapture. Built by the business magnateAndrew Ryan, the city was intended to be an isolated utopia, but the discovery of ADAM, a genetic material which can be used to grant superhuman powers, initiated the city's turbulent decline. Jack tries to find a way to escape, fighting through hordes of ADAM-obsessed enemies, and the iconic, deadly Big Daddies, while engaging with the few sane humans that remain and eventually learning of Rapture's past. The player, as Jack, can defeat foes in several ways by using weapons, utilizing plasmids that give unique powers, and by turning Rapture's defenses against them.