Horror films can receive age ratings of 15 or 18 in the UK. Films rated 15 can contain strong violence, language, sexual content and themes but should avoid encouraging dangerous or illegal behavior. Films rated 18 can contain very strong violence, language, sex, gore and themes without limitation. Examples are given of successful horror films at both ratings, with 18-rated films like A Nightmare on Elm Street and Seven tending to have higher worldwide box office grosses, possibly because their content is not as restricted.

1. Audience research in horror
In a movie that is classified as a 15 there is no theme prohibited so horror
movies can be made for 15 year olds as long as the treatment is appropriate for
15 year olds.
15 classified films can involve the following:
Strong violence, Strong language for example frequent use of the word f**k,
portrayals of sexual activity, strong verbal references to sex, sexual nudity, brief
scenes of sexual violence or verbal references to sexual violence, discriminatory
language and behaviour towards race and sexuality and drug taking is also
allowed in a 15 classified movie.
In many horror films are rated at 15 there can strong threat and menace (s long
as it is not sadistic or sexualized), although the strongest gory images are likely
to be unacceptable.
At age rating fifteen drug taking may be shown, but not to encourage the misuse
of drugs and the misuse of easily accessible and highly dangerous substances.
Such as the misuse of aerosols or solvents, is unlikely to be acceptable at 15.
Dangerous behavior that is self inflicted should not be dwelled upon so that
teenagers are not influenced to mimic the same behavior for example self harm
and suicide should not be dwelled upon.
In a film that is age rated 18 there is no theme prohibited just like movies age
rated 15 although adults are allowed to pick their own entertainment within the
law so it is possible some themes may be offensive to even adult viewers.
18 works are for adults and may contain strong issues such as:
Very strong violence, frequent strong language for example f**k and/or very
strong language for example c**t, strong portrayals of sexual activity, scenes of
sexual violence, strong horror, strong blood and gore, real sex (in some
circumstances) and discriminatory language and behavior towards race and
sexuality.
There is no limit on the number of uses of strong language or very strong
language which can be passed at 18. Uses can be aggressive, directed, and
frequent or accompanied by strong violence. There may also be homophobic or
racist or other discriminatory language used in an 18 film the work could also
explore themes related to this.
At 18 strong violence is allowed and can be portrayed in a lot of detail. There
may even be dwelling on the infliction of pain or injury. Or scenes of strong
sadistic or sexual violence. The strongest gory images are also permitted in this
category.

2. Self harm is still a consideration at this age rating as well as very dangerous or
criminal behavior such as behavior that would pose credible harm or risk to the
viewers may be cut as to make sure it does not influence the audience.
The Skeleton Key (2005)
This film that is age rated at 15 earned a worldwide gross of $91,974,818.
(£58,211,874.04). It raised $16,057,955 (£10,163,256.36) in its first weekend. It
also reached number 2 at the box office and took a total domestic gross of
$47,907,715 (£30,321,319.81)
The Eye (2008)
This is another film age rated at 15. The Eye opened in second place at the U.S
box office with $12.4million (£7,848,096.40). On august the 10th, 2011 the film
had a domestic gross of $31,418,697 (£19,885,238.94) with a foreign gross of
$25,545,945 (£16,168,309.60) which totaled an international gross of
$56,964,642 (£36,053,548.53) in the united kingdom, it grossed $1,398,958
(£885,415.91) in its opening weekend at number 2.
A nightmare on Elm Street (2010)
This movie is age rated as an 18 and on its midnight opening took the record for
most money earned on a midnight opening which was previously owned by the
Friday the 13th remake in (2009) that grossed $1 million (£632,911) whereas a
nightmare on Elm Street finished its midnight opening with a total of
$32,902,299 (£20,824,226.96). As of July 6th 2010, A nightmare on Elm Street
had earned $63,071,122 (£39,918,406.90) in domestic box office making it the
second highest grossing film among the recent slasher remakes although it was
behind Friday The 13th which earned $65million (£4,113,921.50) the movie A
Nightmare On Elm Street since its opening has earned approximately
$52,332,285 (£33,121,678.83) in the overseas box office, leaving it with a
worldwide total of $115,407,296 (£73,042,547.12).
Seven(1995)
This is another 18 rated movie on its opening on September 22nd 1995 it was
released in 2,411 theatres where it grossed $13.9 million (£879,746.29) and it
then went on to gross $100.1million (£633,543.91), in north America and earned
$227.1million (£143,734,088.10) in the rest of the world making seven the
seventh highest grossing film in 1995.
Judging from these values both ratings appear to have large audiences that are
willing to pay to see these movies overall it seems that movies with a rating of
18 appear to earn the most money this could be because the older generations
may feel that films that are rated 15 are to childish and might have a lot of stuff
missed from the movie such as extreme gore etc. this could result in them
watching more movies that are rated 18 because gore isn’t censored in those
films.