Protective actions are those strategic actions taken to help detect potential attacks and to shield oneself from attack while attacking. While protective actions may be in reaction to some action, they are more preemptive than reactionary. Protective actions may be preparatory, such as avoiding a suspicious group of people, or they may be actions that occur as part of your attack. For example, while armor may be used as a defensive measure, it was designed for protection while attacking.
On the battlefield, armor is not something to defensively hide behind, it is a protection used while attacking. Thus amour is designed for both protection and mobility. Sometimes the armor itself, such as a shield, may be used as a weapon in an attack. Armor, such as sparring safety equipment, is best used as a part of a active offense, not as a passive defense.
Although one punch may kill, it is usually a series of punches that kills. Thus, instead of defending against an attack, such as a punch, you should "attack the weapon" by attacking the punching arm in way that prevents it from being used again as a weapon. This is a protective action rather than an defensive action. Protective actions permit you to seize and keep the initiative in self-defense situation.