hoist with one's own petard
Meaning
To be harmed or defeated by one's own plan, device, or trap, especially one intended to harm others.
Origin
Imagine the perilous world of 16th-century siege warfare. Among the arsenal was the 'petard,' a formidable, bell-shaped explosive device designed to blast open fortified gates. Yet, deploying a petard was a terrifying gamble. The 'enginer,' or sapper, responsible for setting it risked premature detonation, sending them literally "hoist"—thrown skyward—by their very own bomb. This vivid, deadly imagery was immortalized by Shakespeare in Hamlet, where he quips about the 'enginer hoist with his own petard,' capturing the bitter irony of a creator destroyed by their own destructive invention. The phrase thus exploded into the English language, forever denoting the misfortune of being undone by one's own machinations.
Examples
- The politician tried to expose his rival's past, but old scandals of his own resurfaced, leaving him hoist with his own petard.
- She set a trap to discredit her colleague, only to find the evidence she fabricated pointed back at her, and she was hoist with her own petard.