What are the requisites of self-defense in the Philippines?
"Self-defense, as a justifying circumstance that exonerates criminal liability, requires the following essential elements: (1) unlawful aggression on the part of the victim; (2) reasonable necessity of the means employed to prevent or repel such aggression; and (3) lack of sufficient provocation on the part of the ...
In order to invoke self-defense, certain conditions must be met such as unlawful aggression, reasonable necessity of the means employed to prevent or repel it, and lack of sufficient provocation on the part of the person defending himself.
First, with exceptions, the defendant must prove that he or she was confronted with an unprovoked attack. Second, the defendant must prove that the threat of injury or death was imminent. Third, the defendant must prove that the degree of force used in self-defense was objectively reasonable under the circumstances.
To invoke self-defense, in order to escape criminal liability, it is incumbent upon the accused to prove by clear and convincing evidence the concurrence of the following requisites under the second paragraph of Article 11 of the RPC, viz: (1) unlawful aggression; (2) reasonable necessity of the means employed to ...
Self-defense under Article 11, paragraph 1 of the Revised Penal Code necessarily implies a deliberate and positive overt act of the accused to prevent or repel an unlawful aggression of another with the use of reasonable means. The accused has freedom of action. He is aware of the consequences of his deliberate acts.
Ruling of the Court
The indispensable requisite for either of these justifying circumstances is that the victim must have mounted an unlawful aggression against the accused or the stranger. Without such unlawful aggression, the accused is not entitled to the justifying circumstance.
Upon motion, the accused may be allowed to defend himself in person when it sufficiently appears to the court that he can properly protect his rights without the assistance of counsel. Philippines, Revised Rules of Criminal Procedure, 2000, Rule 115, Section 1(c).
In the 2008 case District of Columbia v. Heller, the Supreme Court held that the "Second Amendment protects an individual right to possess a firearm unconnected with service in a militia, and to use that arm for traditionally lawful purposes, such as self-defense within the home."
"the use of force to protect oneself, one's family or one's property from a real or threatened attack. Generally. a person is justified in using a reasonable amount of force in self-defence he or she reasonably believes that the danger of bodily harm is imminent and that force is necessary to avoid the danger."
- Unlawful aggression.
- Reasonable means employed to prevent or repel it.
- Lack of sufficient provocation on the part of the person defending himself.
What is Article 11 of the Revised Penal Code?
11. That the crime be committed in consideration of a price, reward, or promise. 12. That the crime be committed by means of inundation, fire, poison, explosion, stranding of a vessel or intentional damage thereto, derailment of a locomotive, or by the use of any other artifice involving great waste and ruin.
Article 51 of the Charter states the following: “Nothing in the present Charter shall impair the inherent... The doctrines of self-defense are qualified by the requirements of retreat.

Thus, the elements of defense of stranger are: (1) unlawful aggression; (2) reasonable necessity of the means employed to prevent or repel it; and (3) the person defending be not induced by revenge, resentment, or other evil motive.
The doctrine of imperfect self-defense has been defined as "an intentional killing committed with an unreasonable but honest belief that circumstances justified deadly force".
The justifying circumstances are self-defense, defense of relatives, defense of stranger, state of necessity, fulfillment of duty or exercise of a right and obedience to superior order.
Actual or material unlawful aggression means an attack with physical force or with a weapon, an offensive act that positively determines the intent of the aggressor to cause the injury.