

One trick that helped me is that psychopaths tend to frame things in an either or, where the either is, you do what they want you to do, and the or is, you are a horrible person.
When you find that yourself in that situation, always pick the horrible person option.
What they think of you doesn’t fucking matter.
Once they realize that they can’t manipulate you, they’ll get bored and move on.
Early on in their first game, my players suffered a T.P.K.
A squadron of horrible die rolls killed all three party members in their first battle.
I’m talking skeletons rolling nat 20s against level 3 characters who kept rolling twos and threes for the entire battle.
But they didn’t die.
Instead, they awoke to find themselves in front of the BBEG who enslaved them with a cursed crest and then sent them out to scour the world for a specific list of objects where they were contractually bound to be released once they delivered them all.
This effectively let me railroad the campaign just enough to get the party started.
(This is what I would be saying if I had realized that I could do this immediately instead of staring slackjawed in disbelief as 30 minutes into a well-planned campaign, every single party member died and then accused me of being too hard of a GM and… yeah.)