Hoist by His Own Petard/Tabletop Games


 * Truly sadistic GMs in just about any game have been known, instead of Railroading difficult PCs, to give them just enough leeway to get in over their heads due to their own actions and decisions.
 * Mishra in Magic: The Gathering relied heavily on his machines and weapons, to the point of falling to the manipulations of a cult of machine worshipers.
 * Then there are redirection spells, meaning that the spell your opponent hurled at your face is suddenly pointed at their own nether regions. Ow.
 * Dungeons & Dragons
 * One early 1st Edition AD&D adventure from Role Aids concluded when the hero shows the Big Bad a branch from a tree in which the villain had gotten trapped as a young boy. This triggers a panic attack in which the Big Bad cries aloud: "That tree tried to kill me! Kill me!" Unfortunately for the evil wizard, the obedient flesh golem Mook at his side takes its orders very literally, and compliantly snaps its maker's neck.
 * A medusa is not affected by the gaze of others of her kind, but is affected by her own gaze, should she be tricked it into viewing her reflection in a mirror; this has some justification, as some legends say the race was a formerly-human society whose leaders became so incredibly vain and narcissistic that the gods punished them with a monstrous form that nobody would ever admire. A medusa thus cannot admire herself in a mirror without dying.
 * In Greyhawk, the tyrannical mage Tuerny was eventually tricked into getting trapped inside an artifact of his own invention: the Iron Flask that bears his name.
 * Dragon magazine introduced a spell for the Ravenloft setting that guarantees mind control will Go Horribly Wrong, as if attempting to read the minds of the nightmare creatures found on the Demiplane of Dread is not enough. Florin deLucier tired of other enchanters trying their hands at Dementlieu intrigues and "spoiling his fun", and devised Corrupt Charm to dissuade people from this. It does nothing unless the target is enchanted. But if it is, charm or suggestion spells gradually give the victim obvious, increasingly obsessive, and then jealous devotion to their casters, and any memory suppressed via magic or hypnosis gradually comes back… twisted to vilify whoever suppressed it, for an extra kick.
 * In Warhammer Fantasy Battle and Warhammer 40,000 this is a danger with daemonweapons. Misfire also does this.
 * In 40K the perils of the warp rule does this for psykers - especially if you're a Librarian casting vortex of doom.
 * Large blast weapons with short ranges can fly right back at the thrower or hit nearby troops. It is entirely possible to completely miss whoever you were aiming at, and obliterate your own tank.
 * Several of the Skaven weapons can invoke this when they inevitably go awry. Orks still have some element of this, but is largely toned down in recent editions.
 * One Paranoia mission calls for a volunteer to test an experimental "traitorkiller". When activated, it.