|From: The Last House on the Left (1972)|
|From: The Texas Chainsaw Massacre (1974)|
The Texas Chainsaw Massacre (1974) is very loosely based on the story of serial killer Ed Gein, but the details of the narrative and the incredible presentation both arise from Tobe Hooper, Kim Henkel and DP Daniel Pearl, among others, not from accurate historical details.
It gives us pause. It creates uncertainty.
It also makes us sympathize, and consider what it might be like to drive to rural Texas and run out of gas, or to accidentally pick up a gang of four criminals, etc.
The horror movies that employ the on-screen "based on a true story" card deliberately play on this fact; the fact that the darkness inside us is very real, and present in reality.
|From: The Blair Witch Project (1999)|
In this way, I suppose, the filmmakers' avoid an outright lie. We just think the films are claiming a truthful basis because that's what we are conditioned to expect.
|From: Picnic at Hanging Rock (1975)|
|From: Return of the Living Dead (1985)|