Branching storylines are narrative structures that allow a story to diverge into multiple paths based on choices made by the reader or player. This technique is commonly used in video games, interactive fiction, and some novels, where decisions can lead to different outcomes, characters, and endings. These storylines enhance engagement by giving the audience a sense of agency, as they can influence the direction of the plot. Popular examples include choose-your-own-adventure books and video games like The Witcher series, where players' choices significantly impact the story's progression and conclusion.