Right to freeload laws work as I describe. Although no employees are forced to "join a union" in the sense of signing a piece of paper joining the union, in all cases they are union employees in practice. That is, the union collectively bargains their working conditions, the union supports them via grievance if the employer doesn't follow the contract, and so on. The right to freeload allows for such a person to get by without paying dues - that is, the cost of providing these collective bargaining and legal representation services.