hoist by one's own petard
Definition from Wiktionary, the free dictionary
- For tis the sport to haue the enginer / Hoist with his owne petar.
- (idiomatic) To be hurt, or destroyed by one's own plot or device, of one's own doing which one intended for another; to be "blown up by one's own bomb".
- He has no one to blame but himself; he was hoisted by his own petard.
- In the US, the forms in "hoisted" are about as common as the forms in "hoist", in contrast to other usage of the past and past participle in which "hoisted" is fifteen times more common.
to be hurt or destroyed by one's own plot or device