Their weapon is humor and used to disguise the venom of their intent. In the wilderness they use their humor to disarm you when you have lost focus and begin to become comfortable. The minute you let your guard down they slowly start to let their true poisonous nature rise to the surface.
The humour starts of lightheartedly but over time slowly progresses to subtle insults and insinuations of how your kingdom should be ruled. By allowing them into your court they pose a threat because if they were able to disarm you, your advisers will be no match for their cunning ways. They will slowly start to sway the people in your inner circle to their way of thinking and before you know it you have coup that could have been avoided on your hands.
Everyone likes a good laugh but if someone is goin out their way to constantly have people in tears their is a motive behind that. It’s like people that are too too nice. Deep down you know something just aint right with them but you can’t put your finger on it. The jester wants a kingdom but is too lazy to build one on his own and doesn’t have the discipline or the vision to see it to completion.
To the jester it is easier to infiltrate an existing kingdom and wreak havoc through horseplay. The jester wants what you have built from determination for himself. A kingdom in the hands of a jester is doomed for failure in the long run because no matter ruthless he is no one takes him seriously. His subjects will love it at first but grow tired of his antics and plan to overthrow him from the throne. Do not let your kingdom end up in the hands of the jester unless you are comfortable letting everything you bled for go up in smoke.