In almost half of the states courts allow a lawsuit for breach of the promise to marry. This claim is based on the idea that an engagement creates an enforceable promise to marry, with the necessary elements of a contract present—the offer (proposal), acceptance (of the proposal), and consideration (mutual promises exchanged). These laws are sometimes referred to as heart balm laws—presumably a reference to the jilted party looking for something to soothe their broken heart.

In most states that allow a party to a broken engagement to pursue a claim for breach of contract against the party who called off the engagement or refuses to get married, the contract to marry does not have to be in writing (some contracts, such as for the sale of real estate, have to be in writing to comply with the statute of frauds).

In states that do recognize a claim or cause of action for breach of the promise to marry, the plaintiff (party filing the lawsuit) may be able to recover money it spent in reliance on the promise to marry, such as the cost of an engagement ring, wedding dress, or rental of the wedding or reception venues. These damages are generally known as compensatory damages, as they are designed to compensate the plaintiff for their out-of-pocket losses.

But the plaintiff in a lawsuit for breach of the promise to marry cannot get the court to order the other party to go through with the marriage or perform the contract—a remedy known as specific performance that is available in some breach of contract lawsuits.

Perhaps because of the emotional nature of engagements to marry; the difficulty for courts in determining who was at fault in terminating the engagement; and the risk of such a claim or lawsuit being used to extort the party who terminated the engagement, some states have enacted statutes that prohibit lawsuits based on a claimed breach of the promise to marry. These laws are usually located in a state’s statutes—often in the family code or domestic relations code.

In states that prohibit or do not recognize breach of contract claims for breach of the promise to marry, some parties to broken engagements have instead attempted to file a lawsuit claiming fraud. Fraud usually requires the plaintiff to prove the defendant knew the statement (“I promise to marry you”) was false when it was made, or that the defendant acted with reckless disregard for the truth of the statement (the defendant didn’t know whether the defendant would marry the plaintiff or not, but proceeded recklessly in promising to marry the plaintiff, and the plaintiff relied on the representation that the defendant would marry).

Laws regarding the availability of a claim for breach of the promise to marry vary from state to state and may be located in a state’s statutes, or in its court opinions (common law or case law).

In South Dakota, breach of promise to marry is not a recognized cause of action. South Dakota has abolished 'heart balm' actions, which means that individuals cannot sue for damages based on a broken engagement or a promise to marry that was not fulfilled. This change reflects a modern view that personal relationships should not be subject to contractual enforcement in this manner, and it aims to prevent the misuse of the legal system for emotional grievances. While some states may allow for such lawsuits, South Dakota does not, and individuals cannot seek compensatory damages for expenses related to a broken engagement. However, if there is an element of fraud involved, a person might explore other legal avenues, such as a fraud claim, but this would require proving that the defendant knowingly made a false promise with the intent to deceive.