Each country has a prescribed "forcepool", which lists "allowable builds" as well as forces initially on the map (around a quarter of Germany's forces start the game on the map - for other countries the proportion is much higher). Units built each turn appear at once in the home country (except a rebuilt 9-factor fleet - see below). Infantry costs 1 BRP per factor, armour 2 BRPs per factor, and air, naval and paratroop units 3 BRPs per factor (e.g. 15 BRPs for a whole air unit). In Winter 1941 and the early turns of 1942 the USSR may - for a stiffening in her victory conditions - build some units for free (the "Siberian Transfer", only half of which may be armour) representing transfer of troops from the Manchurian garrison after Japan goes to war with the USA. Most countries add a few new units to their force pool in 1942. The USSR's forces are initially feeble, but she adds more powerful infantry and armour units in 1942. Germany adds some new armour and infantry units in 1943 and 1944.