Black has a number of ways to meet the Trompowsky, some of which avoid doubled pawns, while others allow them. The most common Black responses are discussed here.
2... Ne4 is the most common reply. Although Black violates an opening principle, his move attacks White's bishop, forcing it to either move again or be defended.
*3. h4 defends the bishop, and Black should avoid 3...Nxg5? since that will open up a file for the White rook. Instead Black can start making a grab for the centre and kick the White bishop away with a timely...h6 advance.
*Usually, White retreats with 3. Bf4 or 3. Bh4. In this case, Black will try to maintain his knight on e4, or at least gain a concession before retreating it.
*3. Nf3? is rarely seen except among amateurs; after 3... Nxg5 4. Nxg5 e5! Black regains the lost time by the discovered attack on the knight; White's center is liquidated and he has no compensation for the bishop pair.
2... e6 also avoids doubled pawns since the queen can recapture if White plays Bxf6. The move 2...e6 also opens a diagonal for the Black king's bishop to develop. On the other hand, the knight is now pinned, and this can be annoying.
2... d5 makes a grab for the centre, allowing White to inflict doubled pawns. If White does so, Black will try to show that his pair of bishops is valuable, and that White has wasted time by moving his bishop twice in order to trade it off. Black usually recaptures away from the center with 3...exf6, preserving a defensible pawn structure and opening diagonals for the queen and dark-squared bishop, however 3...gxf6 is also common. Alternatively, White can transpose into the Richter-Veresov Attack with 3.Nc3 or the Tartakower Variation of the Torre Attack with 3.Nf3.
2... c5 also makes a grab for the centre, planning to trade off the c-pawn for White's d-pawn. Again, White can inflict doubled pawns, and again Black will try to make use of his bishop pair.
2... g6 enables Black to fianchetto his dark-squared bishop. If White immediately captures the knight, Black must recapture away from the center with 3...exf6.
2... c6 is an offbeat line in which Black intends...Qb6, forcing White to defend or sacrifice his b-pawn. White can play the thematic 3. Bxf6 or 3. Nf3, but must avoid 3. e3?? Qa5+, when White resigned in Djordjević vs. Kovačević, Bela Crkva 1984—"the shortest ever loss by a master".
White can also play 2. Bg5 after 1. d4 d5. This is known as the Pseudo-Trompowsky, Hodgson Attack, Levitsky Attack, Queen's Bishop Attack, and Bishop Attack, and is covered in ECO code D00. Play can transpose to the Trompowsky if Black plays 2...Nf6.
