Mistake, as in cases of mistaken payments or mistaken improvements. Another's discharge of a joint obligation. Emergency services performed for the defendant's benefit, Compliance with a judicial order later modified. Defendant may enrich himself by means that we condemn as unjust but for which we would not impose tort liability in the absence of enrichment. Duress is the leading example, although some jurisdictions now consider duress a tort.
Sometime restitution is an alternative to tort.
Generally, the more culpable defendant's behavior, and the more direct the connection between the profits and the wrongdoing, the more likely that plaintiff can recover all defendant's profits. Equitable lien is a hybrid, granting a money judgment and securing its collection with a lien on the specific thing. The restitutionary remedy gives plaintiff a property right in the thing wrongfully taken or withheld from him and in its identifiable proceeds. This property right prevails over the claims of other creditors. It prevails, to some extent, even in bankruptcy.