The slasher movie is one of the most successful and prolific subgenres to swamp the horror movie world. There is no strict definition of a slasher but they often share a number of plot devices that allow a movie to fit into this category. The typical slasher involves a number of rebellious teenagers either unintentionally trapped or intentionally trespassing in an isolated setting while being creatively murdered by an unknown psychopath. The psycho will usually have a defined method of murder and gimmick such as a mask or preferred weapon. Often the reason for the killers instability is the result of a traumatic past event and the victims are usually connected to this event in various degrees of vagueness. A final surviving heroine is a common plot device (the final girl). There is often one final scare to remind us that it might not all be over and leave open the possibility of a sequel.
The origins of the slasher will constantly be disputed. Alfred Hitchcock's Psycho was a turning point in horror history and began to define the "rules" of a slasher although these concepts had been used before. The golden age of the slasher was the late seventies to the early eighties spawning a number of anti-heroes resulting in huge franchises; Freddy Krueger from A Nightmare on Elm Street, Michael Myers from Halloween and Jason Voorhees from Friday the 13th are now all household names of murderous villains. The nineties saw a slasher revival resulting in numerous ridiculous, fairly light hearted but still often quite shock filled and extremely gory horror films.
The slasher subgenre has been greatly influenced by other subgenres such as Italian giallo, splatter films and exploitation films and has gone on to influence other areas of horror inspiring filmmakers worldwide.