A criminal code (or penal code) is a document that compiles all, or a significant amount of, a particular jurisdiction's criminal law. Typically a criminal code will contain offences that are recognised in the jurisdiction, penalties that might be imposed for these offences, and some general provisions (such as definitions and prohibitions on retroactive prosecution).
Criminal codes are relatively common in civil law jurisdictions, which tend to build legal systems around codes and principles which are relatively abstract and apply them on a case-by-case basis. Conversely they are not as common in common law jurisdictions.
The proposed introduction of a criminal code in England and Wales was a significant project of the Law Commission from 1968 to 2008. Due to the strong tradition of legal precedent in the jurisdiction and consequently the large number of binding legal judgements and ambiguous 'common law offences', as well as the often inconsistent nature of English law, the creation of a satisfactory code became very difficult. The project was officially abandoned in 2008 although as of 2009 it has been revived.
In the United States, a Model Penal Code exists which is not itself law but which provides the basis for the criminal law of many states. Individual states often choose to make use of criminal codes which are often based, to a varying extent on the model code. Title 18 of the United States Code is the criminal code for federal crimes. However, Title 18 does not contain many of the general provisions concerning criminal law that are found in the criminal codes of many so-called "civil law" countries.
Criminal codes are generally supported for their introduction of consistency to legal systems and for making the criminal law more accessible to laypeople. A code may help avoid a chilling effect where legislation and case law appears to be either inaccessible or beyond comprehension to non-lawyers. Alternatively critics have argued that codes are too rigid and that they fail to provide enough flexibility for the law to be effective.