This article is devoted to new issues of complicity in a crime in the criminal codes of Russia and foreign countries. It examines the very concept of complicity and its responsibility, the legal nature of complicity, the theory of complicity, including accessory theory, complicity with an inappropriate subject or subject acting inadvertently or innocently, types of accomplices: organizer, performer, accomplice, instigator and new species - initiator, concealer, provocateur, connivance, "thief in law" and their responsibility, forms of complicity: group of persons (co-execution), group of persons by prior agreement, organized group, crime nd organization, criminal organization "thieves in law", complicity in a crime with a special compound and special issues such as the participation excess of the perpetrator, the voluntary renunciation of accomplices