Typical characters in psychological thriller films include stalkers, convicts, criminals, and psychotic individuals who present a threat. Innocent victims and vulnerable characters are also often featured to generate sympathy from audiences and a sense of fear. Authority figures are sometimes included but tend to be unable to provide help due to the nature of the genre. These characters frequently have dark pasts or obsessions that motivate their present dangerous behaviors, and exploring the cause of this through the film's plot is common. Combining character traits can make for more exciting storylines that surprise audiences.