A recording medium, which is provided by a content provider and allows the content provider to control messages, has recorded thereon content and a program executed at a time of playback of the content by a playback apparatus. The program causing the playback apparatus to interact with a different program prestored in the playback apparatus and executed at the time of the playback of the content and to transmit, to the different program, a message determined according to the result of the interaction. The playback apparatus includes a reading unit reading the program from the recording medium at the time of the playback of the content, a startup unit starting up the read program, an interaction unit interacting with the program, and a processing unit receiving a message corresponding to a result of the interaction from the recording medium and performing a process corresponding to the received message.