The book aims to shed light on the system of preliminary criminal liability enshrined in the General Part of the Criminal Code, which is expressed in sections 30 and 31. Based on this examination, the problematic areas of the provisions are identified, and the various factual questions are addressed. In particular, references to the regulations on authorship and participation, as well as attempts and withdrawal, come to the forefront, with the specifics of preliminary criminal liability always being the focal point of consideration. Another objective of this work is to integrate the aforementioned provisions on preliminary criminal liability into the framework of penalizing preliminary behavior in general. To this end, the focus extends beyond sections 30 and 31 to the preliminary criminal offenses enshrined in the Special Part of the Criminal Code. The problems and frictions that arise in this context are then exemplified using a specific provision - section 176 (5) - and are addressed with a proposed solution.