A practical joke is when you do or say something funny or silly to trick someone into laughing. It might be as simple as making a funny face or as creative as planning a big surprise. The point of a practical joke is to make someone laugh and have fun. Practical jokes usually involve tricking someone into thinking one thing is true, when it is actually not. For example, you might tell someone that a place you were going to visit is closed, when really it is open.