Albin Countergambit

The Albin Countergambit is a chess opening that begins with the moves:
and the usual continuation is:
The opening is an uncommon defense to the Queen's Gambit. In exchange for the gambit pawn, Black has a central wedge at d4 and gets some chances for an attack. Often White will try to return the pawn at an opportune moment to gain a positional advantage.
In the "Encyclopaedia of Chess Openings" the Albin Countergambit is assigned codes D08 and D09. 
History.
Although this opening was originally played by Cavallotti against Salvioli at the Milan tournament of 1881, it takes its name from Adolf Albin, who played it against Emanuel Lasker in New York 1893. Though it is not played frequently at the master level, Russian grandmaster Alexander Morozevich has recently made some successful use of it.
Main line.
The main line continues 4. Nf3 Nc6 (4...c5 allows 5.e3 because Black no longer has the bishop check) and now White's primary options are 5.a3, 5.Nbd2, and 5.g3. Perhaps White's surest try for an advantage is to their king bishop with 5.g3 followed by Bg2 and Nbd2. Black will often castle . A typical continuation is 5.g3 Be6 6.Nbd2 Qd7 7.Bg2 0-0-0 8.0-0 Bh3.
Variations.
Lasker Trap.
The black pawn at d4 is stronger than it may appear. After 3. the careless move 4.e3 can lead to the Lasker Trap. After 4...Bb4+ 5.Bd2 dxe3 6.Bxb4 is a blunder—Black plays 6...exf2+ 7.Ke2 fxg1=N+ and Black's position is superior. The Lasker Trap is notable because it is rare to see an underpromotion in practical play.
Spassky Variation.
In the Spassky Variation White plays 4. e4 to take advantage of the fact that an "en passant" capture must be made immediately after the enemy pawn advances. So now after 4...Bb4+ 5.Bd2 the capture ...dxe3 is no longer available to Black.
References.
Bibliography