When it comes to genres that deliver a rush of adrenaline, the two best known contenders are horror and thriller. Both seek to provide a rush of excitement. Both can be either prescriptive or cautionary tales. So what’s the difference?
A great deal, actually. When examined closely, horror and thrillers each have very key elements. Perhaps the easiest way to understand these differences is by contrasting each:
Theme
The theme of a genre is the key idea driving the plot. Both horror and thrillers tend to have either prescriptive or cautionary themes.
In prescriptive themes, the protagonist must overcome an extreme antagonistic force in order to subvert either death or a fate worse than death (hell/damnation, mass genocide, extreme torture).
In cautionary themes, the protagonist is unable to overcome the antagonistic force and becomes victim to death or a fate worse than death. Usually in a cautionary theme, the protagonist makes some critical error or fails to achieve their goal because of their failure to use a skill or instinct.
The key difference in the theme of a horror and thriller comes down to this, though:
Horror: The antagonistic force is speculative, paranormal, supernatural, or unexplained by the natural world.
Thriller: The antagonistic force is a person or organization explainable by the “real” world.
Core Emotion
The core emotion is the emotional response the genre seeks to elicit from the reader.
Horror: The horror genre seeks to terrify or create dread. In other words, to horrify.
Thiller: The thriller genre seeks to create excitement, suspense, anxiety. Or, put more simply, to thrill.
Tropes/Genre Conventions
Horror: The severity of the actions committed by the antagonist tends to escalate. Protagonists tend to be unable to escape from a tightly controlled setting where the antagonist is in a position of superior strength. Key elements of fear are revealed through teasing readers with known threats.
Thriller: The antagonist may not escalate a threat/crime in a thriller, as often the crime is what the protagonist is seeking to subvert. Protagonists tend to be able to escape their setting and antagonist as they seek to solve a puzzle or prevent a crime. Key elements of thrills are offered in ways unsuspected by the readers that rely on suspense and plot twists. Unpredictability is key to a thriller.
Despite the differences, horror and thrillers have a lot of cross-over. Some would argue that the best of each genre borrows from the other, in fact. Both also include a wide variety of subgenres under each (psychological horror, slasher horror, medical thriller, military thriller, etc.). Most importantly, both genres lend themselves to being unconventional. The more predictable, the less likely each is to elicit the required effect on the reader. So think outside the box. Thriller and horror readers are counting on your ability to come up with something they could never imagine.
