At-will employees are those who work without employment contracts. An employment contract can be a collective bargaining agreement between an employer and a labor union or an agreement between an individual and his employer. Being an at-will employee allows you to leave your job without advance notice, but you must live with the uncertainty of potentially losing your job at any time.
For an employee, the primary advantage of being an at-will employee is that you can walk off your job at any time for any reason. You are not required to give advance notice to your employer. If you receive a more attractive job offer and you want to accept the new position and start work immediately, you can quit your present job without giving notice and without breaching an employment contract.
Uncertainty is the primary disadvantage of being an at-will employee. Just as you can leave your job at any time without notice to your employer, your employer can terminate your employment at any time without notice to you. Your employer is not required to tell you the reason for terminating your employment, so you may not have an opportunity to explain the circumstances of the behavior that led to your termination.
At-will employment can be advantageous for an employer who wishes to terminate a poorly performing employee. The employer need not tell the employee why she is being fired; it is sufficient to merely inform the employee that she is being terminated, effective immediately. If an employer suspects the employee has violated company policies but does not want to incur potential legal liability with accusations, the at-will employment doctrine lets the employer end the employment relationship without a potentially litigious explanation.
Employee backlash over the potential for unfair terminations has led some state legislatures to provide safeguards for at-will employees. For example, Montana's Wrongful Discharge from Employment Act was enacted in 2009 in response to complaints that companies were using the at-will employment doctrine to cheat long-term employees out of pension and vacation benefits. Under the Montana law, a discharged employee can sue for wrongful termination if the employer terminated him because he refused to violate public policy, if the termination was not for good cause, or if the employer's termination violated its own personnel policies.