Any good attorney would look at the facts of what the employer is requiring and opine on whether that is illegal discrimination or otherwise violates the applicable employment law and then advise what to do from there. The issuance of a right to sue letter is pretty meaningless in terms of determining how strong or weak the employee’s case is for illegal discrimination by the employer. Why? Because the EEOC provides the right to sue letter for any case that it does not choose to handle itself regardless of whether there is a strong case against the employer or not. Thus, all that the right to sue letter tells you is that the EEOC decided it didn’t want to litigate this case for the employee and it’s up to the employee to decide what to do from there. Indeed, an employee has the right to ask the EEOC for an immediate right to sue letter if he or she wants, which the EEOC will then issue without having done any investigation. The importance of the right to sue letter is simply that the employee must first get that letter prior to filing suit against the employer in court. The vast majority of complaints made to the EEOC end in a right to sue letter; the agency takes only a very, very small number of cases to litigate itself.
All that said, the issue of required dress can sometimes lead to illegal sex discrimination if men and women are being treated significantly different and there is no bona fide business purpose served by the differing treatment. If both male and female servers are required to wear flapper era costumes then it will be nearly impossible to make out a good sex discrimination claim. But if men are allowed to wear whatever they want and only women have required costumes that may be more of a problem for the employer. The exact details matter.

