Red herrings

Red herrings

A red herring is a diversion used to distract the audience from the original idea. Red herrings are often seen in films, adventure games, and puzzles.  In films, a red herring can often be found in Alfred Hitchcock stories, where characters  turn out to be anything but what the viewer expects them to be. Red herring don't just occur with characters is could be the plot too.

Here is an example of a red herring;
 but no one assumes that there will be a twist and the character is ill because of previously unknown food allergy, or an innocuous food poisoning mishap. At that point it would be shocking twist to discover that the person is actually being poisoned by a illness.

 Say you have a character who is mysteriously ill. Everything presented in the movie leads the audience to believe that the character is being poisoned by a certain Character.