Specifies the main weapon of the TechnoType for which this flag is set.
The Primary weapon is always used when:
Force-firing at the ground
Attacking overlays (such as walls). Note that a unit whose Secondary weapon can attack walls, but Primary weapon can't, will not, in fact, be able to attack walls.
The unit's Secondary weapon's warhead's Verses value for the Armor type of the target matches that for the unit's Primary weapon.
This needs testing
The following section contains information that has not been personally confirmed by the revision's author; readers are encouraged to test it themselves and update the section accordingly.
Scanning the area for targets.
Red Alert 2 and Yuri's Revenge introduced units with special-case methods for specifying weapons - the IFV, Prism Tank and Gattling Cannon use WeaponX in place of Primary.
Current Primary Weapon
The weapon that a unit considers to be its actual primary weapon is not always determined simply by Primary. If the unit has both TurretCount and WeaponCount flags set then it will use WeaponX instead. If the unit is elite then it will use ElitePrimary or EliteWeaponX respectively instead.
If a unit has a current primary weapon then it is used as the unit's default DeathWeapon.