3.d4 exd4 4.Qxd4: the queen takes back is variation 2 of 6 in the Philidor Defence course, a beginner opening course for Black (ECO C41). It runs 20 moves and begins 1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Qxd4 Nc6 …. White takes back with the queen. Black gains time by attacking it with ...Nc6. After the trade on c6 Black gets the two bishops, castles short and has a solid game. In the lesson every move is explained on a board and then drilled; it is free.
Move by move
1. e4 – White takes the centre.
1... e5 – Black claims an equal share.
2. Nf3 – White develops and attacks e5.
2... d6 – Black defends e5 with a pawn.
3. d4 – White attacks e5 again.
3... exd4 – Black takes the pawn.
4. Qxd4 – White takes back with the queen. The queen is strong in the centre, but it can be attacked.
4... Nc6 – Black develops with an attack on the queen.
5. Bb5 – The bishop pins the c6 knight, so the queen can stay on d4.
5... Bd7 – Black breaks the pin and develops.
6. Bxc6 – White trades so that the queen can stay in the centre.
6... Bxc6 – Black takes back and gets the two bishops. The c6 bishop aims at e4.
7. Nc3 – White defends e4 and develops.
7... Nf6 – Black develops and attacks e4 again.
8. Bg5 – The bishop pins the f6 knight.
8... Be7 – Black breaks the pin and gets ready to castle.
The lesson goes on for 4 more moves, each with its explanation.