The Sicilian Defense, which is suitable for players of all levels, has long been the most played opening against 1.e2-e4 and its popularity continues to grow. The reason is that sharp and complicated positions arise, which offer black excellent dynamic counter play. In the first part, the author treats all possible deviations before reaching the basic position with 1.e5 c5 2.Kf3 d6 3.d4 etc. ­– such as the Closed Sicilian, the Morra Gambit, the Alapin Variation, the Grand-Prix Attack, the continuation 3.Bb5+ etc. Since it is impossible to accommodate all systems with their extensive and widely ramified lines in a single book, it is limited to one of the most popular systems – the Najdorf Variation, which leads to an uncompromising fight with good black counter chances. The renowned chess author Jerzy Konikowski, a FIDE master and a seasoned player, sheds light on the secrets of the Sicilian Defense. In 18 theoretical chapters and a practical section with 74 fully commented games, he explains the strategic principles and tactical subtlelties. Based on the material offered, the reader can compile a complete personal repertoire against 1.e2-e4.