The first thing any St Andrews student learns is to not step on the "PH" set in stone outside the busy entrance to St. Salvator's Quadrangle. A misstep could result in failing exams or, if a final year student, the loss of your entire degree.
Who would bring such bad luck to hardworking university students? Patrick Hamilton was an influential abbot at St Andrews who brought the reformist teachings of Martin Luther to Scotland. Because these teachings were heretical at the time, the archbishop sentenced him to death in 1528. Hamilton was burnt at the stake outside St Salvator's chapel and the University quadrangle.
The fire burned for an agonizing six hours. During this time, Patrick Hamilton is said to have unleashed a curse on the future students of St Andrews who set foot in the place where he burned. His initials were set in stone in honor of his martyrdom (and perhaps as a warning not to step there). If you look up at the wall over the entrance to the Quadrangle, you can see Patrick Hamilton's face glaring out from a stone above the arch.