FIG. 1. Against the Caro-Kann
The Blackmar Diemer GambitThey say the King's Indian Attack is a great and easy to learn system against any of Black's opening. Yes it's easy to master but I must say it's too slow a system against the Caro-Kann, the Scandinavian(Center Counter), and the Alekhine.
More to the spirit of fighting chess is the Blackmar Diemer Gambit.
1. It's also easy to learn,Against the Caro-Kann we have 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.f3
Against the Alekhine we have 1.e4 Nf6 2.Nc3 d5 3.d4! (Transposes to BDG. Black expects e5 or exd5) 3... dxe4 4.f3
Against the Scandanavian or Center Counter Defense we have 1.e4 d5 2.d4! (Transposes to BDG. Black expects exd5) 2... dxe4 3.Nc3 Nf6 4.f3