Chess Opening Theory/1. e4/1...c5/2. Nf3/2...Nc6/3. Nc3

Sicilian with 2...Nc6 B30 Sicilian defence → 2...Nc6 3. Nc3 White develops their knights to their most active squares. White usually intends to put their knight on c3 eventually: by playing it, now White waits to open the centre with d4 until they have more information about how Black intends to play. This move suggest the possibility of not playing d4, and instead playing a closed position. 3...e5 is the main move. This capitalises on White's hesitation and prevents White from getting to play d4 after all. 4. Bc4 is the main continuation, as now Black's cannot play ...e6 to limit the bishop, and the position resembles an Italian game where Black has somehow gotten in c5. Otherwise, Black may keep things in more familiar Sicilian territory with 3...g6, 3...d6, or 3...e6, where White can then choose between 4. Bb5 or 4. d4, transposing to a main line open Sicilian. Theory table 1.e4 c5 2.Nf3 Nc6 3.Nc3 3 Sicilian, Taimanov ...e6 d4  Sicilian ...d6 d4  References See also Sicilian Defence