Screenwriter Richard Matheson died last month leaving an impressive collection of work including the novel and later screenplay for The Legend of Hell House. The story was filmed by John Hough and released in 1973 and is a solid addition to the canon of British horror movies. Matheson's novel is a knowing re-imagining of the 1959 story The Haunting of Hill House by author Shirley Jackson. This was filmed by Robert Wise and released as The Haunting in 1963 to an excellent reception. The two works are very similar in plot, but quite different in the execution of their celluloid adaptions.
Broadly, both tales feature small groups of psychic investigators who stay in a notorious mansion reputidly haunted by the ghost of a tyrannical aristocrat. The drama is played out through the in-fighting and paranoia amongst the group, and their battle against the house as it tries to breed discord and frighten them away. The more vulnerable psychics are battered, while the cooler scientists are baffled then antagonised (particularly through the ill-treatment of their spouses). Things don't end well and audiences are left with a muted sense of uneasiness.
The earlier Haunting is a tightly-woven supernatural thriller relying on clever lighting, camera effects and sound design. It is, I think, the better of the two by quite a distance. It is also noteworthy for featuring an early an relatively sensitive cinema portrayal of a lesbian character. The psychic Theodora's homosexuality is implicit in the script (although earlier drafts were not so subtle) and serve to add believable tension to the film. Legend is not without merit. Matheson's tale is more gratuitous and scares through graphic violence and sexuality.
Both tales are good exercises in the "Ten Little Indians" horror trope. This is the term for those tight tales set in single locations where the protagonists are lined-up to die. Their demise is assured, but exactly how it happens is what keeps the audience's attention. Legend and Haunting provide ingenious solutions to this and make great additions to the canon.