morality play

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A drama in the 1400s and 1500s using allegorical characters to portray the soul's struggle to achieve salvation.
• noun Something viewed as exhibiting a struggle between good and evil and offering a moral lesson.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun a type of allegorical drama towards the end of the Middle Ages that demonstrates a moral theme such as a character's inner struggle to attain moral enlightenment or salvation

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an allegorical play popular in the 15th and 16th centuries; characters personified virtues and vices