define plot device
â LittleshyFiM on the usage of this trope on My Little Pony: Equestria Girls  Rainbow Rocksnote For added humour, the TV Tropes logo appears as he says this. A plot device is an object or character in the story whose purpose is purely to drive the Plot, maintain its flow, or resolve situations within it. It could be something everybody wants to obtain, a device that must be destroyed, or an annoying teenager who must be protected at all costs.