* To set the tone or theme of the work. The epigraph might be a quote that directly relates to the main idea or message of the piece.
* To introduce a particular character or idea. The epigraph might be a quote from a character in the work, or it might be a saying that reflects a particular character's philosophy.
* To provide context for the work. The epigraph might be a quote from a historical event, a literary work, or a philosophical treatise that helps to explain the setting or the meaning of the work.
* To add an extra layer of meaning or ambiguity. The epigraph might be a quote that is seemingly unrelated to the work, but that actually offers a hidden commentary or suggestion.
Epigraphs can be used to great effect, adding depth and complexity to a work. However, they are not always necessary, and they can sometimes be distracting. It is up to the writer to decide whether an epigraph would be beneficial to their work.