Your company's handbook should:
Include a precise definition of the terms of the at-will nature of the employment relationship; and Clearly explain that employment can be terminated: At any time; With or without cause; and With or without notice, either by your company or the employee.
Regardless of your handbook's at-will language, your company may remain vulnerable to an allegation that:
An employee's termination violated public policy. For example, an employee is fired because of "whistle blowing" to a government agency; or An employee's termination violated a specific statute. For example, the federal Age Discrimination in Employment Act.
At will language:
At-will language can be extremely threatening to employees, raising doubts about job security. From a legal standpoint, precisely written at-will language is valuable; from a human resources standpoint, at-will language can be problematic. On balance, your company may choose to include at-will language and resolve fears among personnel through employee education.
Update Employment Manuals annually:
California labor laws are constantly changing and the new administration has implemented numerous changes for this year. It is recommended that at the beginning of each year, your employment manual be updated by competent labor law counsel.
Warning: One Size Does NOT Fit All:
Be cautious of using a pre-canned or boilerplate employment manual, as one size does not fit all. Your employment manual should be custom tailored to fit your labor pool size, industry and specific needs.