Alternatively, units can have access to a new order: FORTIFY. A unit ordered to fortify spends the entire season building fortifications (insert gratuitous list of fortifications here). While fortifying, that unit's strength is effectively reduced to zero; the unit can be easily dislodged by a single unsupported attacking unit. Therefore, when ordering a unit to fortify its own territory, it is suggested to order neighboring units to support-hold the fortifying unit in order to prevent dislodgement. Fortunately, the fortification order cannot be interrupted by an unsuccessful attack, unlike support orders. After a unit has successfully fortified its territory, a small castle icon appears in the territory; a unit holding a fortified territory effectively has its strength doubled in regards to defense, as if it were the recipient of a support-hold order from the fortifications themselves. Fortifications can be considered stationary units which always support-hold any unit occupying the same territory, yet do not count towards your supply-center/unit count and are an exception to the one-unit-per-territory rule. Moving a unit out of a fortified territory due to movement or dislodgement abandons the fortifications, which the abandoning unit judiciously destroyed in order to prevent capture by the enemy; the only way to prevent the loss of an abandoned fortification is to move another unit you control into the fortified territory on the same turn that the previously-occupying unit leaves.