The system and method of mixing pitch and roll commands from a flight control computer to produce fin deflections applied to as few as two fins to simultaneously produce both a rolling moment and a pitching moment. The system may be mechanical or digital where actuators can be linear or rotary, digital or analog. Deflections of the fins are generated which produce pitch and roll moments where addition of pitch and roll commands determines deflection commands to be sent to a first fin and subtraction of pitch and roll commands determines deflection commands to be sent to a second fin.