If you’ve ever had a career in the arts, or know someone who has, you are likely aware that saying the word “Macbeth” inside a theatre is strictly taboo unless one is rehearsing or in the midst of performing Shakespeare’s dark tragedy. Doing so is almost universally believed to bring about bad luck or even disaster. To avoid the portentous curse, actors refer to the play by a variety of euphemisms such as “The Bard’s Play” or “The Scottish Play.”

According to folklore, the play’s history of bad luck began with its first performance (circa 1606) when the actor scheduled to portray Lady Macbeth died suddenly and Shakespeare was forced to replace him. In another 17th-century production, held in Amsterdam, the actor playing King Duncan was allegedly killed in front of a live audience when a real dagger was used in place of the stage prop during the stabbing scene. Likewise, actor Harold Norman, who reportedly did not believe in superstition, died after his stage battle became a little too realistic while playing Macbeth in 1947. Productions of the play have also been the center of raucous audience riots, including one in 1721 at Lincoln’s Inn Fields Theatre and another in 1772 at Covent Garden. In 1849, a long-standing rivalry between fans of British actor William Charles Macready and American Edwin Forrest turned violent during a production at New York’s Astor Place Opera House, leaving 22 dead and more than 100 injured.

Some believe Shakespeare brought the curse upon his own play by using authentic spells in the three witches’ dialogue, while others believe that a production that has been staged for more than 400 years is bound to have its fair share of accidents. Either way, most thespians don’t want to take any chances. So what’s the antidote for accidentally uttering the forbidden word? Simple. Exit the theatre, spin around three times, spit over your left shoulder and either recite a line from Shakespeare or unleash a profanity.