Deciding whether a 12-year-old is ready for horror movies depends more on their individual emotional maturity and temperament than their chronological age. At 12, most children are in a transitional phase where they are beginning to understand the difference between cinematic fiction and reality, but their brains are still highly sensitive to "jump scares" and disturbing imagery. Experts suggest starting with "PG-13" horror or "gateway" films that focus on suspense rather than graphic gore or psychological trauma. It is often helpful to watch the film together so you can gauge their reaction and discuss the "behind-the-scenes" mechanics of how the scary effects were made, which can demystify the fear. If your child is prone to nightmares, anxiety, or has a history of being easily overwhelmed by intense media, it may be better to wait another year or two before introducing more intense genre classics.