A metadrama can either refer to a piece within a piece, or to a self-aware production or piece. For example, A Midsummer Night's Dream can be considered metadramatic both in the sense that another play (Pyramus and Thisbe) is acted out within it, and because it can be said that it comments on the nature of drama/emotion in and of itself. Viz., Shakespeare was not just writing a play about people experiencing things, but was in fact commenting on the nature of experience. Because, technically, an individual experiencing the piece cannot avoid the nature of his/her experience anything can be considered metadramatic in this way. Despite, and partly due to, this ambiguity metadrama most typically will mean that the illusion of the production is broken. In other words, (keeping with theatrical examples) at least one character is aware of the audience and/or production(something that does not happen in A Midsummer Night's Dream). This is most common in prologues, think Romeo & Juliet, as well as with narrators. But, do not ignore that it can refer to self-awareness within a production, which includes, but is not necessarily included in, a character/s acknowledging the fiction of the play. An example of this more abstract understanding would be Theseus' (from A Midsummer Night's Dream)opinions about theatre and art mirroring Shakespeare's own (which is commonly thought). Think of this as self-reflexive, also.
