It blocks the threat if you get a threat while you have 0 points. This is to make sure no shields are wasted. If there is a threat but you have 0 points, it wont take away from your shields.
If I ever own a pet Llama, he is going to be named Brock. He will eat only organically grown alfalfa casserole, and I will teach him the ways of life.
lol
 "Qoosh"){kind=icon}
 "Monster Legions"){kind=icon}
 "Relive Your Life"){kind=icon}
 "JumpingLine"){kind=icon}
 "Raze"){kind=icon}
 "The Visitor: Massacre at Camp Happy"){kind=icon}
 "Don't Shit Your Pants"){kind=icon}
 "Lucky Shapes!"){kind=icon}
 "Where is bridge"){kind=icon}
 "Flight"){kind=icon}
 "Racing Comrade!"){kind=icon}
 "Robot Dinosaurs That Shoot Beams When They Roar"){kind=icon}
 "Fade"){kind=icon}
It blocks the threat if you get a threat while you have 0 points. This is to make sure no shields are wasted. If there is a threat but you have 0 points, it wont take away from your shields.