What is fee simple defeasible and when can ownership be lost?

Fee simple defeasible is a form of ownership that can be terminated if a specific condition is violated. There are two main types: fee simple determinable, which automatically ends when a stated condition occurs, and fee simple subject to condition subsequent, which requires the grantor to take legal action to reclaim the property after a violation. For example, a deed granting land on the condition that it be used only for educational purposes creates a defeasible fee. If the condition is broken, ownership may revert to the grantor or the grantor's heirs.