Wrongful termination is a term that generally refers to a person being fired illegally. Many terminations that people think of as "wrongful" aren't illegal. In most states, employment is "at will". This means that the employer can fire the employee for no reason or any reason. However, there are two main reasons why a termination may be illegal- discrimination and contracts.
Employers cannot discriminate against employees are the basis of age, race, sex, national origin, disability, and a variety of other reasons. Employers cannot discriminate against an employee because he or she has "whistle blown", which is reporting illegal activity of the employer. They also cannot discriminate against an employee for engaging in other protected activities, such as filing workers' compensation claims.
If any employee has a contract with the employer, as is common when an employee belongs to a union, the employee probably cannot be fired without just cause. Contracts can be written or implied. However, this type of dispute is characterized as a breach of contract case, rather than a wrongful termination case.
