The most common grounds are: being fired because of a protected characteristic; being fired shortly after you complained about discrimination, harassment, or unpaid wages (retaliation); being fired for taking legally protected leave; being fired in breach of an employment contract or a clear public-policy violation (such as refusing to commit fraud, or for filing a workers’ comp claim). A bad or unfair reason is not automatically illegal – the key is whether the real reason was one the law prohibits.