Rationing is a technique used to distribute food and goods for survival needs when normal distribution chains are broken; rationing cards are a classic of urban survival scenarios, as well as authoritarian and inept regimes.
In times of war or catastrophe, when normal commercial channels are
often disrupted significantly or it is required to reassign production
resources toward very focused efforts like maintaining troops in the
battlefield, local governments and authorities usually use rationing to
limit the amount of food and other essential goods so that every person
among the population gets what is needed, not more, and if possible, not
less. Under such - often understandable circumstances - authorities try
to fight speculation using different control systems from which
rationing cards stands as the most common.