An employment contract is an agreement between an employer and an employee that explains the employment relationship. Contract terms vary from person to person and employer to employer. With an employment contract, you may have more rights than if you were an at-will employee. Having an employment contract does not automatically mean you are not an at-will employee. Some contracts may specifically state that an employee is at will.
Many contracts are ambiguous.
The more limitations the contract puts on your employer's behavior, the more likely it is that you are not an at-will employee. The one thing a contract cannot do is waive your rights under federal or state law. For example, if your employer is required to pay you overtime, you cannot sign a contract waiving the right to overtime. Even if you have a contract, employers are still subject to most laws regulating wages, prohibiting discrimination and sexual harassment, requiring accommodations of disabilities, imposing safety standards, providing medical and family leave time and benefits to employees who are injured on the job, and requiring payment of unemployment compensation. In addition, having a contract does not mean your employer can never fire or discipline you.