Most counters in the game represent corps, or Soviet armies roughly the size of other countries' corps. In general two counters may stack in a hexagon, or five on a bridgehead (a bridgehead provides unlimited supply for the first post-combat supply phase, and supply may be traced to it in subsequent turns as if it were a port). Only armour units have a Zone of Control, which costs an extra two movement points to pass through (German and US armour have 6 movement points per turn, enabling them to move through two zones of control, other countries' armour units only 5; US armour units, and the two German SS Panzer corps added in 1943, also have 5 strength points rather than the usual 4). British and US infantry have 4 movement points rather than 3, reflecting their higher degree of motorisation. Units remain the same throughout the game, as both sides copied one another's technological advances throughout the war.