Character shield 

a shield that says the character can't lose a fight that he's in,or if he does,he'll always win in the end.

Watch the Evil Dead movies for the Examples.

Character shield by Unknow Man March 24, 2005

Main Character Shield 

The invincible shield protecting the main character in a formulaic Hollywood flick.

Oh, he jumped off the Empire State Building holding an orphan while being gunned down by helicopter bullets and hellfire missiles? I'm not even scared he's going to die. He definitely has a main character shield.

Main Character Shield by tigeru August 8, 2016