A cessation of work or a refusal to work or to continue work by employees in combination or in accordance with a common understanding for the purpose of compelling an employer to agree to terms or conditions of employment. Usually the last stage of collective bargaining when all other means have failed. Except in special cases, strikes are legal when a collective agreement is not in force. A rotating strike is a strike organized in such a way that only part of the employees stop work at any given time, each group taking its turn. A sympathy strike is a strike by workers not directly involved in a labour dispute – an attempt to bring pressure on a employer in a labour dispute. A wildcat strike is an illegal strike violating the collective agreement and not authorized by the union.