Tortious interference, also known as intentional interference with contractual relations, in the common law of torts, occurs when one person intentionally damages someone else's contractual or business relationships with a third party, causing economic harm. As an example, someone could use blackmail to induce a contractor into breaking a contract; they could threaten a supplier to prevent them from supplying goods or services to another party; or they could obstruct someone's ability to honor a contract with a client by deliberately refusing to deliver necessary goods.