You are not initializing
protected String name;
protected int lifePoints;
of your Magician class
public Magician(String name, int lifePoints) {
super(name, lifePoints); // initializing fields of parent(Entity) not of child(Magician)
// TODO Auto-generated constructor stub
}
Also, protected should be used in Parent class, not in the child. Please revisit the basics of Java.