Criminal law is the body of law that defines crimes, prescribes punishments, and regulates the criminal process's substantive guarantees. In Nepal, the general and special criminal law now lives principally in the Muluki Criminal Code, 2074 (2017) (in force 2018) and the CriminalProcedure Code, 2074, together replacing the criminal halves of the Muluki Ain, 2020 — plus special statutes (narcotics, banking offences, anti-money laundering, public debt? no — e.g., the organised crime and anti-corruption statutes, the Public Offences and Punishment Act, the elections laws, environmental crimes).
Nature — the five-point anatomy:
1. Public law: the State is party; the wrong is conceived as against society, not merely the victim;
2. Penal, not compensatory: the aim is punishment — retribution, deterrence (general and specific), incapacitation, rehabilitation — although modern codes (including the 2074 Code) increasingly pair punishment with victim compensation, making criminal law partly reparative;
3. Ultimate ratio (last resort): criminal law is the State's heaviest instrument — the principle of ultima ratio demands criminalization only where other social controls fail;
4. Strict construction and legality: crimes and punishments are statutory; no crime without law (nullum crimen sine poena nulla... — Unit 3's principles);
5. Universal and territorial: every legal system has one, and each claims authority over defined territory and persons (jurisdiction — Section 5).
Functions of criminal law (answer to "why criminal law?"): upholding public order and security; protecting fundamental rights and interests (life, body, property, reputation, chastity, state security); expressing and reinforcing moral limits; deterring and rehabilitating; doing justice on behalf of victims.