The skill as described in Classic Traveller:
“The individual has led troops in battle or on adventures and is possessed of a knowledge and self assurance which will make for a capable emergent or appointed leader.”
Like this guy here:
Leadership is a specifically military skill, then. I had long assumed that Leadership was good for any instance of a PC directing NPCs. There's nothing wrong with playing it that way, but that's not what the skill description indicates.
“Leadership is a required ability to control a group of more than six no player hirelings or soldiers. Such a group will tend to obey the general orders of the character with the highest leader expertise. Reaction throws are necessary when the leader and the group first meet. DMs may be applied: +1 per level of leader expertise when consulting the reaction table.
Leader-3 or better is sufficient to allow soldiers to obey orders without hesitation. Leader-4 or better will allow a positive DM when recruiting soldiers or hirelings for adventures. The throws and DMs for such hirelings depend on the situation imposed by the referee.” This is the only direct reference to hirelings I could find in CT.




