The sound comes from Baldi's Basics in Education and Learning, a 2018 indie horror game built around a parody of 1990s educational software. Players answer maths questions while Baldi, the teacher, stalks the school corridors, and the ruler slap marks his growing anger as mistakes pile up. Clips from playthroughs spread across YouTube and short-form video, where the slap became shorthand for instant punishment in edits outside the game. It remains popular alongside other horror game sounds like the FNAF jumpscare scream because a single sharp crack needs no context to land.