What are those three weird legal words that sound similar and describe a persons obligations?

The three legal terms you're referring to are "duty," "obligation," and "liability." These Words describe a person's responsibilities or commitments under the law. "Duty" often refers to a moral or legal responsibility, "obligation" denotes a binding commitment to act or refrain from acting, and "liability" implies legal responsibility for one's actions, particularly in the context of potential legal consequences.