Doctor Faustus is typically considered an early modern tragedy, given its dark subject matter and the fate of its central character. However, it takes its structure and many of its dramatic elements from another genre of drama called a morality play. Morality plays are a genre of drama from the Medieval and early Tudor period of English history (roughly the twelfth through sixteenth centuries). Of the five surviving English morality plays, four were composed during the fifteenth century.
Morality plays are generally identified by their use of personification to portray abstract concepts. Another name for this device is allegory. Frequently, English morality plays would create "characters" out of abstract notions like the virtues and the vices, presenting them as real entities that could walk, speak, and share their own opinions. Additionally, morality plays also featured angels and devils who were most often fighting over the fate of a particular human protagonist.
Doctor Faustus is considered by many to be a late morality play, as it was originally performed in the late sixteenth century, around 1592, just before the height of early modern English drama. Marlowe's play features both a parade of personified sins – the seven deadly sins in costume – and a number of devilish figures who serve Satan and attempt to influence Faustus's behavior. The original play was also written in a series of twelve scenes rather than the traditional early modern structure of a play in five acts. This twelve-scene framework is more reflective of Medieval drama and the morality play genre.
Notably, the term "morality play" is a critical invention; morality plays do not refer to themselves as such in the way that comedies, tragedies, and history plays often do. As such, referring to Doctor Faustus as a morality play is merely a way of identifying its major theatrical characteristics and connecting it to a larger dramatic tradition.