Any change an employer makes without the union's consent. The subject of unilateral change is ever changing due to NLRB and court rulings. However, unilateral change falls into 3 categories; unilateral change before a first time contract, during bargaining, and during the contract's terms. The NLRB recognizes that an employer must bargain all changes in regards to hours of work, rate of pay, and other conditions of employment with the employee's bargaining representatives. Generally, these changes must be bargained to impasse before a change is implemented.