“It’s just coincidence,” Philip Kerr says of the superstitions that swirl around Shakespeare’s “Macbeth.”

“I don’t personally believe that spirits are throwing rocks at us or anything.”

Kerr, professor of theater and drama in the School of Music, Theatre & Dance, will direct the Department of Theatre & Drama’s performance of “Macbeth” this weekend at the Power Center for the Performing Arts.

It’s well known in showbiz that “Macbeth” is cursed. In one 17th-century production, the actor playing King Duncan was allegedly murdered when a real dagger was used instead of a fake one for his stabbing scene. At least 25 people died in the Astor Place Riot of 1849, which was spurred by a rivalry between two well-known actors both playing — who else — Macbeth. And in a 1953 production starring Charlton Heston, a sudden gust of wind blew flames from a realistically staged battle scene onto Heston. He was severely burned — as it turned out, someone had soaked his tights in kerosene.

Kerr has been lucky so far in this production, save a few bouts of swine flu in the cast — still, he insists, “touch wood and please don’t say anything.”

When Kerr played the Scottish lord Ross in the 1988 Broadway revival of “Macbeth,” it was a different story. That show was plagued by changes in directors, sets and actors, and lead Christopher Plummer (known for his leading roles in movies like “The Sound of Music” and “Up”) was injured multiple times in multiple accidents.

There are several theories behind the “Macbeth” curse. Some say Shakespeare lifted some of his lines for the “Macbeth” witches from actual spells, causing real-life witches to jinx the play. Others point to King James, the ruler for whom Shakespeare allegedly wrote “Macbeth,” who believed in witchcraft and even wrote a book on demonology.

Even saying the name “Macbeth” aloud in the theater, some say, can lead to grave misfortune. And so it is often referred to as “The Scottish Play,” and its lead actors as “Mac-ers.”

Depending on the theater company, there are certain cleansing rituals for those who accidentally say “Macbeth” — including one in which the culprit turns around three times, spits over his or her left shoulder and recites a line from another work of Shakespeare. In some circles, one just has to swear. But safe within the walls of the Power Center, Kerr isn’t afraid to let his actors say the name.

“(The character of Macbeth) is intriguing, but not totally sympathetic, and that may contribute to (the superstitions),” Kerr added. Shakespearean tragedies tend to have flawed leads — Hamlet and Romeo come to mind — but Macbeth is different, dark and at times downright unlikeable.

“I believe that Macbeth is essentially a good man whose mind is poisoned by the witches and corrupted further by his wife,” counters Music, Theatre & Dance senior Thomas Wolfson.

Wolfson might be a little biased — he plays Macbeth — but he doesn’t see the character as “a moustache-twisting villain.” Wolfson will indeed sport a moustache for the performance, however.

“Macbeth” is Shakespeare’s shortest and most violent tragedy. It deals with dirty, primal ambition — the power couple at its center consists of a man who considers murdering his king but doesn’t have the guts and the heartless wife who emasculates him so much that he finally commits the crime.

After three witches deliver a prophecy that he will become king, the Scottish general Macbeth — upon his wife’s urging and taunting — murders King Duncan and assumes the throne.