How To Prove Retaliatory Discharge In Illinois. I've been wrongfully terminated what are my options?Or, were you a victim of retaliatory discharge? You may be able to file a state or federal wrongful termination claim. Reporting of illegal or improper conduct. 4. Can an employer terminate me without advance notice or without giving a reason or an unfair reason for the termination? In Illinois, wrongful termination occurs when an employee is fired for reasons that are illegal under state or federal law. Why Do Managers Retaliate? It also must be reasonably clear that you are complaining about illegal job discrimination. When filing an Illinois wrongful termination claim in Illinois, you will need to show that your firing was illegal.