In fiction, a false protagonist is a literary technique, often used to make the plot more jarring or more memorable by fooling the audience's preconceptions and constructing a character who they assume is the protagonist but is later revealed not to be.
A false protagonist is presented at the start of the fictional work as the main character, but then is eradicated, often by killing them, usually for shock value or as a plot twist, or changed in terms of their role in the story, such as by making them a lesser character, a character who leaves the story, or revealing them to actually be the antagonist.