It may seem unfair, but an employer can fire an “at-will” employee at any time, without good cause – or even without any cause at all. It is a bitter pill, and one that many American workers must swallow. Under the law, you are generally deemed to be employed at-will, unless you can prove otherwise.

Workers who are employed at-will can be fired for no reason, but they cannot be fired for a bad reason. Some reasons are illegal under federal or state law, exceptions to the general doctrine of at-will employment. For example, you cannot be fired for complaining about discrimination, harassment, or safety violations in the workplace, or for complaining about illegal activity. The majority of employers are subject to anti-discrimination laws and cannot fire you based on certain characteristics, such as gender, race or religion. Similarly, you cannot be fired because you have exercised a legal right, such as taking time off for family and medical leave, military service, jury duty, or voting in an election.

Many employers take steps to ensure that the at-will nature of the employment is clearly established and agreed-to by all parties. This is typically spelled out in employment applications and contracts, employee policy and procedure manuals, and may be described as “at-will employment” or simply contain statements that you can be terminated at any time “without cause” or “for any reason.”

Still others have implemented written policies that protect their employees against being fired without good cause, and specify the reasons for which an employee can be terminated. If your employer has adopted such a policy, you are entitled to those protections.  Likewise, if you have signed an employment contract guaranteeing you job security, your employment is not at-will and you are entitled to the protections contained in the written agreement.

Should you sign an at-will employment agreement? Courts have generally held that an employee can be terminated, or not hired, for refusing or failing to sign an at-will employment agreement.While you are not technically required to sign the agreement, if you want to get hired or keep your job, it may be in your best interest to sign the agreement.

Nevertheless, if the at-will agreement contradicts what your employer previously promised you, you may want to think twice about signing on the dotted line. If you relied on the employer’s promises of job security when you accepted the position, you should consult an attorney before signing an at-will agreement. Courts will presume the signed at-will agreement controls your employment, regardless of any prior statements to the contrary.

Just because you sign the at-will agreement does not mean your employer will use it to fire you without cause. There is little to be gained in terminating a productive employee, and most employers will attempt to work with you to resolve any issues. Ultimately, the best way to avoid the perils of at-will employment is to be an outstanding employee. Delivering exceptional job performance is good for the company’s bottom line – and your own.