Chess Opening Theory/1. e4/1...d5/2. exd5/2...Qxd5/3. Nc3/3...Qa5/4. b4/4...Qxb4

The Black queen greedily takes the pawn, accepting White's challenge. White now has an open b-file, so she continues with 5. Rb1.

5. Nb5?! has been tried by some mavericks, setting up some deadly traps.