Usually it is referred to as The Scottish Play
The play is called "Macbeth" by William Shakespeare. It is considered unlucky to say the name of the play inside a theater, so actors often refer to it as "The Scottish Play" instead. This superstition dates back to historical accidents and mishaps that occurred during performances of the play.
Technically you can say Macbeth; there is nothing stopping you, except a lot of theatre people who will get angry with you. The word Macbeth is seen to be very bad luck to actors and actresses. Legend has it that an actor once said Macbeth before he took part in a play and then he dropped dead. The superstition is that if you say the word "Macbeth" in a theatre, except when you are actually performing or rehearsing the play, it's bad luck. You're supposed to call it "the scottish play" instead.
Shakespeare's 1606 play "Macbeth" is widely held by actors to be cursed. There are various reasons why this view is held. To ward off bad luck, the name "Macbeth" must never be uttered by an actor inside a theatre. Instead the euphemism "The Scottish Play" is used.
The cast of Superstition - 2012 includes: Nick Healy
The cast of Macbeth - 1913 includes: Arthur Bourchier as Macbeth Violet Vanbrugh as Lady Macbeth
The cast of Macbeth - 1978 includes: Violeta Gindeva as Lady Macbeth Lyubomir Kiselichki as Macbeth
The cast of Macbeth - 1915 includes: Georgette Leblanc as Lady Macbeth
Macbeth Lady Macbeth Banquo Fleance Malcolm Donalbain Macduff Lady Macduff
Because of a long-standing superstition surrounding the play, Shakespeare's Macbeth is often referred to as "The Scottish Play."The name itself comes from the fact that the play is set in Scotland. It is referred to this way because, according to legend, saying the actual name of the play (Macbeth) inside the theatre will bring tragedy to the production. Some believe simply quoting the play inside the theater but outside an actual rehearsal may also cause the same bad luck.
The cast of Macbeth 2.1 - 2007 includes: Valentina Boriani as Lady Macbeth Rodolfo Mantovani as Macbeth
The cast of Superstition - 1997 includes: Jon Corfino Cassandra Peterson as Elvira
The cast of Superstition - 1922 includes: Jack Devereaux Veta Searl Stafford Windsor