If you are a beginner in chess then play the Cambridge Springs Defense as Black against first move 1.d4 for a start, as this chess opening is pretty straightforward and fairly easy to understand.
1.d4 d5 2.c4 e6 3.Sb1-c3 Sg8-f6 4.Lc1-g5 Sb8-d7 5.e2-e3 c7-c6 6.Sg1-f3 Dd8-a5
Hint: You can play this opening when the white bishop on c1 comes out and moves to g5! Just watch White where he will put his bishop c1.
If the white bishop goes to g5 then Black wants to play Bb4 and Ne4 to put pressure on the white knight on c3, that is not protected by the white bishop sitting already on g5. To move back this bishop from g5 to d2 would mean a loss in time.
White can fall into the following trap and loses a piece. See below
Or White can fall into this trap: 7.Nd2 Bb4 8.Qc2 0-0 9.Bd3? dxc4! (the white bishop on g5 is not protected! If Bxc4 you take Qxg5 and win the bishop!) 10.Bxf6 cxd3! (Zwischenzug!) 11.Qxd3 Nxf6 and you are a piece up and should win. (see diagramm)
In the Cambridge Springs Defence it is important for Black to bring out his inactive bishop on c8. Bring it into the game. For that reason Black usually plays the pawn move e6-e5. This opens the diagonal c8-h3 for the bishop to come out later on. (see next diagramm)
Here Black has just played e6-e5. This makes it possible to bring the bishop out along the c8-h3 diagonal.
When you replay the following chess games please observe where the black bishop goes and what it does. This will speed up your learning process. You might even memorize the story of each black piece, what it does and where it goes.