During the adjustments phase, Powers determine control of supply centers and adjust their unit counts.
Controlling Supply Centers
A Power controls a supply center when one of its units occupies that supply-center province at the end of a Fall turn. Once a country gains control of a supply center, it can leave the center vacant and still keep control of it, as long as that center isn’t occupied by another country at the close of a Fall turn.
Builds and Disbands
After each Fall turn (including retreats, if any), players adjust their units to match the number of supply centers they control. This may result in some units being disbanded (if the player has lost supply centers that year) or in some units being built (if the player has gained supply centers that year).
If a country has fewer supply centers than units, it must disband the excess number of units (owner’s choice of which units).
If a country has more supply centers than units, it can place new units in each unoccupied supply center of its home country that it still controls. It can’t build units in supply centers outside its home country.