Yes. Illinois is an "employment at-will" state, meaning that an employer or employee may terminate the relationship at any time, without any reason or cause. Before filing a lawsuit in court for wrongful termination, you need to file a complaint with the Illinois Department of Human Rights and the EEOC.When an employee is wrongfully terminated, they have the right to file a wrongful termination lawsuit with the help of an employment lawyer. This article covers some of the common legal grounds you might have for suing your employer in Illinois for wrongful termination. The first step in filing a wrongful dismissal lawsuit is evidence gathering. The cause for such termination can vary. The first step in filing a wrongful dismissal lawsuit is evidence gathering. The cause for such termination can vary. Illinois Court Rules. •••. If a court finds that a resignation was actually a constructive discharge, then legally it's the same as if the employee was outandout fired.