Newly trained Builders gain 2 extra build actions.

Although forms of land bondage had been present in civilization before (such as the Roman colonate system), medieval serfdom really began with the collapse of the Carolingian Empire in the 10th century AD. In the period following, local lords needed a ready supply of agricultural labor for their manors, and the peasants needed protection against just about everybody … so the practice of serfdom spontaneously arose in various places across Europe. By the 12th and 13th centuries, serfdom had acquired a strict legal status, for serfs were not slaves and did have rights (however minimal). With the rise of powerful monarchs and central governments, serfdom became less useful, and by 1400 true serfdom was rare … except in Russia.