Petard

The petard is a small explosive charge, typically packed into a metal or wooden case and set with a fuse, that European military engineers of the sixteenth and seventeenth centuries used to breach fortified gates, walls or other barriers by placing the device directly against the target and detonating it, a specialized siege-engineering role distinct from the larger indirect-fire siege artillery of the period. Because the engineer, known as a petardier, had to approach the target under fire and often light the fuse by hand before withdrawing, the device carried a well documented risk of detonating too soon or before the engineer had retreated to safety, a hazard commemorated in the English phrase to be hoist by one's own petard, popularized by a line in Shakespeare's Hamlet, meaning to be caught or injured by one's own scheme or device. Though later eclipsed by more reliable engineered demolition charges, the petard represents an early and historically influential category of hand-emplaced explosive breaching weapon.