The romantic suspense and romantic thriller genres have much in common. In both cases, a romance develops against a backdrop of mystery, danger, and intrigue -- and the two terms are often used interchangeably. However, when contrasted, the difference between the genres is one of scope: The plot of a romantic suspense novel is directly related to the characters involved, while in romantic thrillers, the characters are caught up in larger-scale intrigue.
Romantic Suspense Plots
In a romantic suspense novel, the suspense comes from danger or intrigue that is directly related to the protagonist or the other central characters. The protagonist may have to confront a conflict from her past, or a dangerous force may specifically seek her out.
For example, "Fatal Attraction" is a romantic suspense movie -- the suspense emerges when the protagonist's mistress begins stalking him. One romantic suspense novel is "Snapped," by Laura Griffin. The hero and heroine meet in the aftermath of a sniper attack in a small town, and the plot consists of tracking down the killer.
Romantic Thriller Plots
The romantic thriller differs from romantic suspense in terms of scale. The danger against which the romance develops is larger than the characters involved. They may be caught up in global intrigue -- many romantic thrillers are spy novels -- or meet during a disaster.
"Titanic" is an example of a romantic thriller movie. The romance between the two main characters develops, and is challenged by the larger event of the Titanic sinking. Sandra Brown's novel "Lethal" also shows the form of the romantic thriller. The heroine meets her love interest, an accused murderer, when he breaks into her house, looking for evidence to clear his name after being framed by a conspiracy of human traffickers.