Thriller film, also known as suspense film or suspense thriller, is a broad film genre that evokes excitement and suspense in the audience. The suspense element found in most films' plots is particularly exploited by the filmmaker in this genre. Tension is created by delaying what the audience sees as inevitable, and is built through situations that are menacing or where escape seems impossible. The cover-up of important information from the viewer, and fight and chase scenes are common methods. Life is typically threatened in a thriller film, such as when the protagonist does not realize that they are entering a dangerous situation. Thriller films' characters conflict with each other or with an outside force, which can sometimes be abstract. The protagonist is usually set against a problem, such as an escape, a mission, or a mystery. Thriller films are typically hybridized with other genres; hybrids commonly including: action thrillers, adventure thrillers, fantasy and science fiction thrillers. Thriller films also share a close relationship with horror films, both eliciting tension. In plots about crime, thriller films focus less on the criminal or the detective and more on generating suspense. Common themes include, terrorism, political conspiracy, pursuit and romantic triangles leading to murder. In 2001, the American Film Institute made its selection of the top 100 greatest American "heart-pounding" and "adrenaline-inducing" films of all time. The 400 nominated films had to be American-made films whose thrills have "enlivened and enriched America's film heritage". AFI also asked jurors to consider "the total adrenaline-inducing impact of a film's artistry and craft".