This chapter explores the dual concepts of lawful behavior and legal responsibility as central elements in the regulation of social relations. It begins by defining lawful behavior as conduct aligned with legal norms and examines its types such as marginal, conformist, habitual, and socially active, based on motivation and internalization of legal values. The chapter stresses the role of legal culture and conscious engagement in fostering stable, socially beneficial conduct. The second part analyzes unlawful behavior (offenses), outlining its legal characteristics and structural elements: subject, subjective side (guilt), object, and objective side (harm and causality). It categorizes offenses into criminal, administrative, civil, disciplinary, procedural, and international violations. The final section presents legal responsibility as the coercive response to offenses, detailing its key features, goals, and principles: legality, justice, inevitability, expediency, individualization, guilt-based responsibility, and protection against double jeopardy. Different forms of legal responsibility (criminal, administrative, civil, disciplinary, material) are distinguished by their enforcement mechanisms and legal consequences. The chapter emphasizes that balanced, principled legal responsibility reinforces legal order and encourages voluntary compliance in post-Soviet societies.