Imperialism II: Age of Exploration  Imperialism II: Age of Exploration is a turn-based strategy computer game developed by Frog City Software and published by Strategic Simulations, Inc. (SSI) in 1999. It is the successor to the 1997 game "Imperialism". In "Imperialism II", the player starts as ruler of a 16th-century European country, and must build an empire. Since 2001 Ubisoft owns the rights to the "Imperialism" trademark. Imperialism II is a turn based 4X game, where you have to ""eXplore, eXpand, eXploit, and eXterminate"" in order to achieve victory. The game however focus on the economic aspect by introducing the concepts of variable worker productivity, variable terrain productivity, labor allocation, resource allocation and logistics. The game presents the player with an economic problem that is composed of three allocative dilemmas plus the necessity to supply food for workers and military units plus the necessity to finance scientific research. Raw materials which depend terrain improvements to be extracted and on logistics to be transported have to be processed by workers into semi-finished materials. Those semi-finished materials can then be turned into units or workers, used to increase terrain productivity or used to sustain workers of higher productivity. Logistics also depends on semi-finished materials for expansion through additions to the merchant marine and improvements to the road network. On Imperialism II raw materials have to be transported first and then processed, access is not enough. In order to build a unit or an improvement a specific quantity of specific raw materials needs to be transported and processed into semi-finished materials before it becomes possible to build a unit. An example, to build 1 Ship-of-the-line unit the following quantities of semi-finished materials are required:  This requirement represents in raw-material terms the following:  But in order to build another unit, such as a "Carbine Cavalry" a different mix is needed:  In raw material terms this necessity would mean:   Every worker, ship and military unit requires one unit of food (wheat, meat or fish) every turn. Because of this necessity, enlarging the labor force depends on the increase of the food supply. Increasing the food supply demands semi-finished materials in order to improve farms or expand the merchant marine which can transport fish. Labor has 4 different levels of productivity. Each higher level of productivity requires a unique type of luxury. This element of the game allows the player to increase total production without enlarging the labor force which would require raising the food supply.