I originally included this category in my scary movies section, but I eventually moved it out on its own. Like horror, thrillers have numerous subgenres. There should be a certain amount of suspense in any genre of thriller, so any subgenre could be at least a bit scary. But some subgenres of thriller seem to me a bit more like "scary movies" than others. Like, I probably won't include political, conspiracy, legal, or spy thrillers here (though there could be exceptions). Mostly I'd include certain crime thrillers, or psychological thrillers (though some of those I might include instead under psychological horror). So... I dunno, I'll just make my decisions on a case by case basis. I will say that my main criterion for listing films in the "thriller" category will be that the fear isn't created by monsters or anything supernatural. (Then again, I might have rare exceptions of movies with a supernatural element... just as I might include some thrillers under other scary movie categories even if they don't have anything supernatural about them.) And if that means there's a murderer, chances are they won't be the over-the-top kinds of killers you'd see in slasher movies (though they may or may not have psychological issues). I'll probably also include some natural horror films in this category, as long as the danger really does seem natural; i.e., reasonably realistic animals, viruses, other natural disasters. (Sharks, yes; mutant sharks, no.) I also want to say this category will have some crossover with film noir, mystery, or crime films.