Characteristics

Thrillers often take place wholly or partly in exotic settings such as foreign cities, deserts, polar regions, or high seas. The heroes in most thrillers are frequently "hard men" accustomed to danger: law enforcement officers, spies, soldiers, seamen or aviators. However, they may also be ordinary citizens drawn into danger by accident. While such heroes have traditionally been men, women lead characters have become increasingly common; for an early example see Sigourney Weaver's character Ripley, in the movie Alien, 1979.
Thrillers often overlap with mystery stories, but are distinguished by the structure of their plots. In a thriller, the hero must thwart the plans of an enemy, rather than uncover a crime that has already happened; while a murder mystery would be spoiled by a premature disclosure of the murderer's identity, in a thriller the identity of a murderer or other villain is typically known all along. Thrillers also occur on a much grander scale: the crimes that must be prevented are serial or mass murder, terrorism, assassination, or the overthrow of governments. Jeopardy and violent confrontations are standard plot elements. While a mystery climaxes when the mystery is solved, a thriller climaxes when the hero finally defeats the villain, saving his own life and often the lives of others. In thrillers influenced by film noir and tragedy, the compromised hero is often killed in the process.
In recent years, when thrillers have been increasingly influenced by horror or psychological-horror exposure in pop culture, an ominous or monstrous element has become common to heighten tension. The monster could be anything, even an inferior physical force made superior only by their intellect, a supernatural entity, aliens, serial killers, or even microbes or chemical agents. Some authors have made their mark by incorporating all of these elements (Richard Laymon, F. Paul Wilson) throughout their bodies of work.
Similar distinctions separate the thriller from other overlapping genres: adventure, spy, legal, war, maritime fiction, and so on. Thrillers are defined not by their subject matter but by their approach to it. Many thrillers involve spies and espionage, but not all spy stories are thrillers. The spy novels of John le Carré, for example, explicitly and intentionally reject the conventions of the thriller. Conversely, many thrillers cross over to genres that traditionally have had few or no thriller elements. Alistair MacLean, Hammond Innes, and Brian Callison are best known for their thrillers, but are also accomplished writers of man-against-nature sea stories.