Greek and Roman curses were somewhat formal and official. Called katadesmoi by the Greeks and tabulae defixiones by the Romans, they were written on lead tablets or other materials, generally invoked the aid of a spirit (a deity, a demon, or one of the dead) to accomplish their aim, and were placed in some place considered effective for their activation, such as in a tomb, cemetery, or sacred spring or well.

In the text of katadesmoi and defixiones, the petitioner uttered a prayer or formula that the enemy would suffer injury in some specific way, along with the reason therefor, such as theft or loss of respect.

The Romans, Etruscans, and Greeks in Italy all practiced this custom. Fortunately for us, they buried the curses so well that today we have a body of curse inscriptions to tell us how they practiced their harmful magical works.

Certain objects or places are said to be cursed. Sometimes, the curse was allegedly laid with a purpose; the "Curse of the Pharaohs" is supposed to have haunted the archaeologists who excavated the tomb of Pharaoh Tutankhamen, whereby an imprecation was supposedly pronounced on anyone who violated its precincts by the ancient Egyptian priests.

Tecumseh's curse was reputed to cause the deaths in office of Presidents of the United States elected in years divisible by 20, beginning in 1840 (this alleged curse appears to have fallen dormant in 1980, as President Ronald Reagan, elected that year, failed to die in office).

A number of curses are used to explain the failures or misfortunes of specific sports teams or players. For example, the Curse of the Billy Goat is used to explain the failures of the Chicago Cubs baseball team, who have not won a championship since 1908. Players who appear on the covers of either the Sports Illustrated magazine or the Madden NFL video game have tended to coincidently suffer setbacks or injuries.

Cursed objects are generally supposed to have been stolen from their rightful owners or looted from a sanctuary. The Hope Diamond is supposed to bear such a curse, and bring misfortune to its owner.