The Moscow Variation is a common line that white will use to attack the Sicilian Defense. It begins with the moves:
1. e4 c5 (Sicilian Defense)
2. Nf3 d6
White looks to be aggressive by putting the black king in check on the third move. There are three replies that black has:
Each of these options is viable. Bd7 allows black to immediately put white to the test on if they want to exchange the bishops off the board. Since this tends to be the weaker bishop for black, trading the bishop off here is solid choice for black. If black doesn’t want to give up his bishop he can always move his knight out to protect the king. While Nc6 allows white to trade and give black doubles pawns on the c file, it also gives black the only bishop pair and it should be easy for black to remove the doubled pawns later in the game. If black doesn’t want to worry about doubled pawns then Nd7 is the go to move.
If you would like to learn more about each of these variations be sure to watch the video below.