Hoist By His Own Petard: Radio
Irony is a staple of Radio, including finishing off villains with their own plans.
- Adventures in Odyssey: Dr. Blackgaard's death is doubly ironic. Not only does he become infected with the same lethal virus he was developing, but he commits suicide first, right before his professor-assistant reveals he found a way to create an antidote for the virus.
- In the radioplay Elvenquest on BBC Radio 4, the Genre-savvy villain Lord Darkness played by Alistar McGowen creates, in a series full of lampshading and parody, a machine called "The Petard of Irony"- which takes the worst fate you have ever wished on an enemy and turns it on yourself. The only problem is, the person he uses it on, the so called 'Chosen One', is a dog from our world that's been transformed into a person upon arriving in the world the story is set.
- In one episode of The Navy Lark Povey receives a memo from Admiralty which allows him to get rid of officers that have been at sea for "twiddly-upmty" years and plans to use this as an excuse to drum the crew of HMS Troutbridge out of the navy. Upon appeal it seems the memo can also be interpreted to get rid of officers who were at sea "twiddly-umpty" years ago and the episode concludes with the Admiralty board resolving to throw Povey out (but only after lunch).
- In the crime thriller Paul Temple and the Vandyke Affair, Temple's wife Steve gets a visit from a woman sent to kidnap her on behalf of the titular Mr. Vandyke. While Steve is away, answering a phone call intended to distract her, the kidnapper drugs Steve's coffee. Temple himself then happens to phone - Steve tells the kidnapper that he'd like to speak to her, and while she's away Steve switches the cups. As they both drink their coffee, Steve plays along by mentioning that her coffee tastes bitter. The kidnapper drinks the drugged coffee, starts feeling faint, and as she succumbs to her own trap, Steve tells her that she was on to her all along.