* During the battle royale in RolePlay/YuGiOhEastAcademy, Marcus screws up his entire strategy ''twice'' by misreading his own cards.
* ''Roleplay/DestroyTheGodmodder'' has many such events, the first notable one being the reapers. A massive army of them gets summoned, what happens? The godmodder mind controls them into changing sides. It isn't the worst offender either.
** It turns into this for the godmodder later on, and everyone gets a slice of the action with the Glitch.
** The Virus in game 2. Seems like a great idea, it gives the AGs a fair boost... and then gains self awareness. And decides it wants to kill everything.
** And then there's ninjatwist's Blood Pact charge, also from the second game. It would allow the godmodder a heal of 1 HP for dealing 150,000 damage to his own side and giving the player in question a permanent +1 bonus to his charges. This was done after [[TooDumbToLive the Game Master told him it wouldn't work and during Act Four, where the godmodder was invincible to attacks and capable of summoning and attacking that in one turn]]. It says something when the Game Master not only instantly gave a player a fourth action to kill him, but ''allowed everyone else to do so'', marking the first time in the ''entire series'' a player was directly attackable outside of summoning themself.
* In [[http://www.giantitp.com/forums/showthread.php?183080-Journeys-on-the-TARDIS-3-It-Really-Is-Bigger-on-the-Inside-(Game-Thread) this sadly truncated Doctor Who-themed Mafia game]], the Weeping Angels come off ''very'' badly. How badly? The only player to die was ''their most powerful player''. Their attempt to kill one GenreSavvy player got busted because said player turned out to be ''the Doctor''. Attempts to get in close with said player (who they didn't know was the Doctor) to bust open a potential good guy network killed the aforementioned most powerful player. Ouch.