Soap operas are serial dramas that focus on the lives of multiple characters in each episode. Trailers are used to promote soap operas and appeal to both existing and new viewers, showing characters, storylines, and themes. For example, a trailer for the medical soap opera Casualty would include scenes of disasters and crises with characters in medical uniforms. Steven Neale's theory is that soap opera characters should be stereotypical for audiences to relate to, but they also need original ideas and characters to avoid predictability and create uniqueness.