Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4/3. c3/3...dxc3/4. Bc4/4...cxb2/5. Bxb2

= Danish Gambit Accepted = The pawn is recaptured. White has great attacking chances with her two open bishops and quick development, but Black is up two pawns. A player who is up two pawns can safely assume that they're going to win any endgame that arises, which means White's attack needs concrete results - either material, or checkmate.

Rather than accept those stakes, Black often gambits a pawn straight back with 5...d5 to get her queen and c8-bishop into the game. This is the Schlechter Defence, in which Black can either try to hold onto the second pawn, or return that one too to steer the game into a level, queenless middlegame.

A more ambitious approach is 5...Nf6, the Classical Defence. It looks like the knight is just walking into an e5 advance, but tactical considerations mean it's not that simple.

5...Bb4+ is the Copenhagen Defence. Committing the bishop to b4 invites a later Qb3, but who doesn't love developing a piece with check when you're behind in development?

5...d6 is not fatal, but abandons any hope of active defence in favour of Turtle Mode.

5...Nc6 offers a transposition to the Göring Gambit.

5...c6 hampers the b8-knight and doesn't actually help Black achieve ...d5. Likewise 5...f6 is anti-developing move, and the attempted Scholar's Mate with 5...Qh4 doesn't work.

5...Qe7 is interesting move which plans Qb4+! winning bishop and with two pawns and bishop black is totally winning

Theory table
'''1. e4 e5 2. d4 exd4 3. c3 dxc3 4. Bc4 cxb2 5. Bxb2'''