Closed

With 2. Nc3 White develops toward d5 but postpones d4. The knight blocks the c-pawn and leaves Black more say over d4. Its grip on d5 is what makes the closed setups work: after 2. f4 or 2. g3 Black can strike with 2...d5 at once, while here that break is held back. 2. Nc3 is White's second most common answer to 1...c5 and the chief anti-Sicilian. Most databases begin the Closed Sicilian here, although some writers keep the name for the fianchetto lines. Bent Larsen favored it on the grounds that giving up a center pawn for the c-pawn is positionally suspect. Louis Paulsen used it against Anderssen in 1862, and Boris Spassky later made it a regular weapon.

The traditional scheme is 2...Nc6 3. g3 g6 4. Bg2 Bg7 5. d3 d6, the Fianchetto Variation. Here White chooses between 6. Be3 with Qd2 and possibly O-O-O, and 6. f4 followed by Nf3 and O-O. The usual plan is a kingside pawn advance with f4-f5, while Black seeks a queenside breakthrough first. A common reply is ...e5, the Botvinnik Defense, seen after 6. Nge2 e5 and after 6. f4 e5. The other main approach is the Grand Prix Attack, 2...Nc6 3. f4. White develops the light-squared bishop to b5 or c4 before closing the chain with d3, castles after Nf3, and brings the queen over via e1 or pushes f5. This attacks faster but is less harmonious, and Black usually aims for an early ...d5, often prepared by ...e6 and ...Nge7.

2. Nc3 commits White to little, since 3. Nf3 and 4. d4 can still lead into an Open Sicilian. That shapes Black's choice. 2...Nc6, played in nearly half of all games, keeps Black's pawns flexible until White's plan is clear, but it rules out a Najdorf. 2...d6 keeps that option open. 2...e6 prepares to meet 3. g3 or 3. f4 with 3...d5, as in the Korchnoi Defense, 2...e6 3. g3 d5. For that reason White often transposes to open lines, and Black must know a Kan or Taimanov. 3. Nge2 after 2...Nc6, which Andrew Soltis named the Chameleon, keeps both 4. g3 and 4. d4 available. However, 3...g6 4. d4 then gives an Accelerated Dragon in which White can no longer set up the Maróczy Bind with c4.

Both closed setups have a reputation for giving White practical attacking chances. Engine analysis, though, shows that Black has ample defensive resources, and theory is relatively shallow as a result. Results in the Lichess database are close to even, and the engine judges the position roughly balanced. Rarer tries include the Grob Attack, 2...Nc6 3. g4, and the Portland Attack, 2...Nc6 3. d3 g6 4. g4.