Rocky Horror writer Richard O'Brien on secrets of horror

As Halloween brings its annual offering of scary costumes, Richard O'Brien reveals the secret ingredients to a good horror story.

The Rocky Horror Picture Show writer told the BBC he prefers his horror with a bit of comedy - with "the tongue firmly in the cheek".

O'Brien also said he prefers his most famous work to be seen on stage rather than on screen because of the audience's interaction.

Video journalist: Rachel Curtis