In literature, a paradox is a situation or idea that contradicts itself yet is nonetheless true. In Half Magic, when the children discover the charm, the possibilities seem limitless. However, they soon realizes its inherent paradox: The more frequently they use the coin’s magic power, the more apparent its limitations become.

When Jane first understands the fake coin is magical, she plans to meet with her siblings to determine “how they were going to use this wonderful gift” and to plan their “Enchanted Summer” (28). Viewing the token as a “wonderful gift,” Jane recognizes the power that it holds. It could turn their dreary summer into something enchanted, a power underscored by the capitalization of Enchanted Summer. However potent the charm may seem, it does have limitations, specifically in that it only grants half of a wish. Although this seems easily overcome by doubling one’s wishes, sometimes determining just how to achieve this in a short amount of time can cause complications. All four children, Alison, and Mr. Smith, fall victim to the charm’s limitations.

The theme is developed in each adventure, as the children delight in some wishes but discover that their requests have consequences, especially if not well thought out.