How did Half-Life and BioShock add story lines to first-person shooter games?

Half-Life and BioShock were pivotal in evolving the first-person shooter genre by moving beyond simple "shoot-'em-up" mechanics to incorporate complex narratives and immersive storytelling techniques.12

Half-Life

Released in 1998, Half-Life departed from the standard cinematic plot devices common in the genre at the time. Instead, it pioneered the use of live scripted interactions to tell its story, allowing players to experience the narrative directly within the game world as they navigated a research facility. By organizing the experience into chapters rather than traditional levels and integrating puzzles into the gameplay, Half-Life created a more cohesive and immersive narrative flow.1

BioShock

BioShock (2007) further advanced the genre by blending first-person shooter mechanics with elements of stealth and role-playing games. Its narrative is deeply influenced by player choice; specifically, the decision to either kill or rescue "Little Sisters" introduces a significant element of morality that directly impacts the story line. This integration of ethical decision-making and character development helped set a new standard for storytelling in the genre.32