hoist with your own petard
hoist by/with (one's) own petard
To be injured, ruined, or defeated by one's own action, device, or plot that was intended to harm another; to have fallen victim to one's own trap or schemes. ("Hoist" in this instance is the past participle of the archaic form of the verb "hoise.") I tried to get my boss fired by planting drugs on him, but I was hoist by my own petard when the police caught me with them beforehand.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
hoist with (or by) your own petardhave your plans to cause trouble for others backfire on you.
The phrase is from Shakespeare's Hamlet: ‘For 'tis the sport to have the enginer Hoist with his own petard’. In former times, a petard was a small bomb made of a metal or wooden box filled with explosive powder, while hoist here is the past participle of the dialect verb hoise , meaning ‘lift or remove’.
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