One of the five elements of a role-playing game in my book. The plot is built on two other elements RPG's - the game world (which includes non-player characters) and the player characters. A plot can be simple, like "the queen wants to hire your party to go retrieve a family heirloom that was stolen by a rival nation," or they can be hideously complex, and nothing is as it seems; each new piece of information leads to yet another plot line (see Tom Clancy and Robert Jordan). Each player has his or her own preferences for plot complexity, which may vary with time. As a general rule, the more complicated the plot, the better - most players like it when the plot thickens. The plot is the responsibility of the game master, in who's hands, plot devices are putty to be sculpted.