One of the ways in which Plautus investigates friendship is through his use of the stock characters so central to Roman comedy. Among the twelve stock characters of comedy that Apuleius lists, appears the figure of the sodalis opitulator (the 'helpful mate'), who has not so far drawn much attention. Not only does Plautus use this character frequently, in five of his twenty extant plays he employs not one friend, but two, as a double motif. In these plays, Plautus uses these double stock characters to parody the ideals of friendship which had developed in the literary tradition, and to play with the conventions of drama as part of a metatheatrical approach to comedy. By a doubling of this motif, Plautus highlights friendship, in order to look at other literary or dramatic themes that include the ideal literary friendship, the supremacy of the Plautine slave and drama itself.