One of the other things to consider is that once you blackmail someone into doing something unsavory for you, that becomes more fodder for blackmail.

The only thing to keep in mind is that blackmail is a gun with one bullet. Once you pull the trigger, it's pretty much useless. And if the blackmail-er asks too much of the blackmail-ee all at once, especially if the latter hates the former, it might just appear worth it to take the bullet and let the chips fall.

Persuade and Bargain rolls have been mentioned as the mechanism for how blackmail might work out, but I'd think...