A more thorough explanation:

Definition: Breach of promise is when someone breaks their promise to marry another person. It is also known as a broken engagement. Although it is not actionable in most jurisdictions, it is considered a tort against the person who broke the promise. The idea behind breach of promise is that the promise to marry is like a contract, and the person who broke the promise may have to pay damages to the other person.

For example, in California, a fraudulent promise to marry or cohabit after marriage does not give rise to a cause of action for damages. Similarly, in Pennsylvania and New York, all causes of action for breach of contract to marry are abolished.

Example: Sarah and John have been engaged for a year. They have made plans to get married and have even started looking at houses to buy. However, a few weeks before the wedding, John tells Sarah that he has changed his mind and does not want to get married anymore. This is a breach of promise because John broke his promise to marry Sarah.

Explanation: In this example, John's promise to marry Sarah was like a contract between them. When he broke that promise, he committed a tort against Sarah. However, in most jurisdictions, Sarah would not be able to sue John for damages because breach of promise is not actionable.