hoist with one's own petard or hoist by one's own petard
: victimized or hurt by one's own scheme
Did you know?
The connection between hoise and hoist is a bit confusing. The two words are essentially synonymous variants, but hoist is far more common; hoise and its inflected forms hoised and hoising are infrequently used. But a variant of its past participle shows up fairly frequently as part of a set expression. And now, here's the confusing part: that variant past participle is hoist! The expression is "hoist with (or by) one's own petard," which means "victimized or hurt by one's own scheme." This oft-heard phrase owes its popularity to William Shakespeare's Hamlet in which the titular character says, "For 'tis the sport to have the engineer hoist with his own petar[d]." (A petard is a medieval explosive. The quote implies that the engineer—the person who sets the explosive device—is blown into the air by the explosion of his own device.)