Units are mobile and can be used for operations. Some are useful for carrying resource shipments, others are needed to spy and counter-spy enemies, others can be used to destroy infrastructure, and all can be used to attack or defend a field. Unlike the other elements (citizens, infrastructures, researches, defences), units can be redeployed at will from one city to another belonging to the same player using a deployment operation: they are not permanently binded to the field on which they have been trained.

Like citizens and defences, units use a number system.