Mandatory Rules in the Law of Trusts

The law of trusts consists overwhelmingly of default rules that the settlor who creates the trust may alter or negate. There are, however, some mandatory rules, which the settlor is forbidden to vary. In this Essay, I direct attention to important recent developments in American trust law that have clarified the mandatory rules, and I explore the rationale for these rules. I divide the mandatory rules into two groups: intent-defeating rules that restrict the settlor's autonomy, and intent-serving rules whose purpose is to discern and implement the settlor's true intent.