Final answer:
A realistic setting is not a required characteristic of a fairy tale; fairy tales are known for their magical elements, a moral lesson, and often a happy ending, but they are not set in a realistic world.
Step-by-step explanation:
The characteristic that is not a required element of a fairy tale among the options provided is a realistic setting. Fairy tales are a subgenre of folk tales and typically feature fantastical elements and creatures such as dragons, fairies, and magic. They are often set in a whimsical, made-up world that is quite different from reality, which is a stark contrast to realistic fiction that mimics real-life settings and situations. What does define fairy tales, though, is their inclusion of a moral lesson or message, magical elements, and more often than not, a happy ending. While the other characteristics play a significant role in the structure of a fairy tale, the realistic setting is generally not one of them.