Chess Opening Theory/1. e4/1...c5/2. b4

Sicilian Wing Gambit
2. b4 marks the Sicilian Wing Gambit. There are other wing gambits like this using the b-pawn (for instance, the Evans Gambit); however, this wing gambit is the most common one. The b-pawn push tries to undermine Black's c-pawn control of d4.

This gambit is unsound at the top level, and Black can safely accept it. However, it is common in amateur play.

Black's responses
2...cxb4. Black usually accepts the gambit. White is most likely to play 3. a3 to try to develop the knight by either recapturing on a3 or going to c3.

2...d5. Black can always decline the gambit and attack White's e-pawn.

Theory table
'''1. e4 c5 2. b4'''