This skill increases your recruitment cap, along with juice.
*You get about 1/20 of a level of Leadership every person you recruit through talking about the issues. It's given when they actually join, so you can't scam this by talking to lots of people then sending them away.
*If your immediate subordinates go above 20 juice, you get half of all future juice gains from them, but it goes to Leadership instead of juice. This is the main way to get it.
Note that Leadership is capped harshly by your juice. You can't even finish getting your first level of it until you have 50 juice. But even one level is quite powerful.
Note that the point at which you can teach them Leadership is the same as the point at which you start getting Leadership from your existing characters. If you want them to have more than one point of Leadership each, you'll have to get them a lot of juice that will cross over into your Leadership skill.
The result of this combination is that it's doubly important to have strong, high juice subordinates if you want to have a lot of people with Leadership skill.
Leadership is the type of skill that if you forget about it and play a strong game with a lot of strong characters in your group that go on a lot of site actions, you'll soon find that most of your recruiters have it. If you sit around and play your hand very Conservatively by not doing much dangerous or criminal, you'll have weak Leadership skill, even if you try to work at it. It rewards being gutsy. Even if you do a lot of recruitment, you won't be able to level Leadership up very far without juice, and that comes from taking risks and going out on site actions.—
Unfortunately, leadership was struck from existence in recent versions.