In 2012, the California Appellate court recognized a new lawsuit for those who lose an inheritance due to wrongful interference by someone else. For example, you were going to receive a large gift from a friend and then that plan was either changed or stopped due to another person’s bad acts—such as lying about you or coercing/forcing the decedent from naming you as a beneficiary.
This sounds like a promising legal right, but it can only be used in narrow circumstances. The big road block to bringing an interference lawsuit is that you must not have an adequate probate remedy. An adequate probate remedy is where you have the right to sue in probate court to overturn a bad Trust amendment. Most family members have the right to challenge a Trust in probate court. As a result, they do NOT have a right to bring an intentional interference lawsuit.
It may seem odd, but you cannot bring an intentional interference lawsuit unless that is the only legal right you have. If you have any other rights under the law, then you must pursue those other rights instead. This explains why the intentional interference lawsuit is not used all that often.
Intentional interference applies most often to non-relatives of the decedent. People who are friends, non-married couples, including same-sex couples that are not married or in a registered domestic partnership. In other words, anyone who is not an heir-at-law of the decedent. These people have no other way to bring their legal claims forward other than an intentional interference claim. Of course, they also need evidence that someone intentional interfered with their gift. If a decedent simply changed their mind and decided not to leave a gift to their friend or partner, then there may not be a legal right to sue for that.
Keep in mind, this is just a generalization. Your situation may differ so be sure to talk to a lawyer if you want to know for certain what your legal rights are. You may or may not be able to sue for intentional interference, but it never hurts to ask.