The doctrine of unjust enrichment applies the principles of restitution to disputes that are not governed by a contract between the parties. It characterizes the result of a failure to make restitution under circumstances that give rise to an implied or quasi-contractual obligation to return those benefits.

The courts describe this claim in general principles. For example, courts have stated that a claim for unjust enrichment seeks to restore money where equity and good conscience require restitution; it is not premised on wrongdoing, but seeks to determine to which party, in equity, justice, and law, the money belongs; and it seeks to prevent unconscionable loss to the payor and unjust enrichment to the payee.

Because recovery based on unjust enrichment of another party relies on the court's sense of fairness or equity rather than the law, it is often referred to as the equitable doctrine of unjust enrichment.

In Delaware, the doctrine of unjust enrichment is recognized and applied by the courts when one party has been unjustly enriched at the expense of another, and there is no valid contract governing the transaction between them. This doctrine is rooted in principles of equity, aiming to prevent one party from retaining benefits or money that, in fairness and good conscience, should not be kept. To establish a claim for unjust enrichment in Delaware, a plaintiff must demonstrate that they conferred a benefit upon the defendant, the defendant appreciated or knew of the benefit, and it would be inequitable for the defendant to retain the benefit without payment for its value. Delaware courts will look at the specifics of each case to determine whether an implied or quasi-contractual obligation exists, and whether restitution is warranted to address the unjust enrichment. This equitable remedy is separate from legal remedies that might be available under a formal contract and does not depend on the presence of wrongful conduct, but rather on the justice of the situation.