I didn't know that it is legal to force someone to resign from being able to go to the court. I thought that right to use court to defend ones right is a right

I didn't know that it is legal to force someone to resign from being able to go to the court. I thought that right to use court to defend ones right is a right that cannot be revoked by some agreement. For me it looks as if someone would sign an agreement that company might kill employee if sales target is not met or enslave him and his family.