The article contains an analysis of views on 1. the issue of the features of a prohibited act in the structure of the sanctioned norm, 2. the relation between the circumstances excluding unlawfulness and the features of a prohibited act, and 3. the issue of “the normative features”. Author’s view on what in the statutory provisions, which are regarded to the issue of the scope of 1. the error regarding features of a prohibited act, 2. the error regarding premises excluding unlawfulness and 3. the error regarding circumstances affecting the perpetrator’s consciousness that his behavior is unlawful, should be contained, is presented in the study. There is also a revision of what should enclose the content of the perpetrator’s consciousness, so that it can be assumed that he has fulfilled the features of a prohibited act intentionally. The article discusses the methods of describing in statutory provisions the mental state of a prohibited act and the issue of the error. Author’s view on the method of the interpretation of the distinction between premises of a mental state of a prohibited act and premises constitute conditions of the assignment of culpability to the perpetrator, also is presented in the article. All theoretical considerations were transferred to the current criminal code.