The class conflict and tension that exist in society due to competing socioeconomic interests between people who have and people who have not, as well as different ideologies. Class warfare can take on many different forms including direct violence such as wars fought for natural resources and cheap labor, and indirect violence such as high unemployment, unfair taxation, unsafe working conditions. The conflict can be overt, as with a lockout aimed at destroying a labour union, or covert, as with an informal production slowdown protesting low wages or unfair labour practices.

Marxists argue that class conflict plays a pivotal role in the development of class-based hierarchical societies such as capitalism and feudalism. Marxists refer to its overt manifestations as class war, a struggle whose resolution in favour of the working class is viewed by them as inevitable under capitalism.