The Profession of Heroes: Due to the rise of supervillains, "Pro Heroes" became a legitimate, regulated profession. heroes operate worldwide, and there are international regulatory agencies like the Hero Safety Commission. public Quirk usage without a license is strictly illegal. The law is summarized by the rule: "Using one's Quirk to hurt others is fundamentally forbidden." While civilians are granted exceptions for genuine self-defense, they cannot legally strike back with their powers. The Public Ban: Casual use of a Quirk in public spaces is illegal. This includes boosting your speed, jumping long distances, or using a quirk for minor convenience if it disrupts traffic or poses a threat Self-Defense Exception: You are legally permitted to use your Quirk to shield, dodge, or escape a dangerous situation. However, you cannot use your Quirk to physically attack or retaliate against an assailant, as the law mandates relying on quirkless martial arts or calling a hero. Quirk are officially grouped into three main biological categories. Some analyses also include a fourth overlapping category for Quirks based entirely on building up energy over time. Emitter-Type (発動, Hatsudō) What they are: Quirks that allow the user to generate substances, manipulate their environment, or alter the properties of matter. They typically require conscious activation and focus. Transformation-Type (変形, Henkei) What they are: Quirks that temporarily change the user's physical body—or parts of it—into something else, altering their biological properties or granting them special physical traits. Mutant-Type (異形, Igyō) What they are: Quirks that permanently alter the user's anatomy, giving them constant, unchangeable physical traits that grant them supernatural abilities. Accumulation-Type (蓄積, Chikuseki) What they are: An overlapping sub-classification for Quirks that require the user to continuously build up specific resources—such as physical energy, impact, or sugar—over a long period before they can be used.