10 Horror Movie Tropes That Prove "If It Ain't Broke, Don't Fix It"
3. Demonic Possession, Followed By A Hollywood Exorcism
Often used as the main plot of a horror film, this trope signifies when an evil spirit or demon inhabits a human body. It is not uncommon for the spirit and the body to be total opposites. For example, a Demon thousands of years old inhabiting the body of a child.
Demonic Possessions usually take place after one of the following events in a film: someone dies and/or has sold their soul to the devil, a character uses evil as a toy (a really popular version of this is a character summoning a spirit via a ouija board), or an evil spirit is released after a sealed tomb is opened.
Characters who are suffering from possession will show the following symptoms: Being burned by religious imagery, enhanced strength, foaming at the mouth, speaking in tongues, and having knowledge of things that the victim couldn't possibly know.
The exorcism that follows is often an overly dramatic, violent battle of wills between a priest and the possessed individual involving the splashing of holy water and Latin chanting, with some amazing looking special effects such as levitation, bleeding walls and the physical appearance of the demon in question.
Trope Examples: The Exorcist (1973), The Conjuring (2012), The Exorcism of Emily Rose (2005)